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5,247 commits

Author SHA1 Message Date
Ye Bin
098927a13f ext4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all()
[ Upstream commit 5701875f96 ]

There's issue as follows:
BUG: KASAN: use-after-free in ext4_xattr_inode_dec_ref_all+0x6ff/0x790
Read of size 4 at addr ffff88807b003000 by task syz-executor.0/15172

CPU: 3 PID: 15172 Comm: syz-executor.0
Call Trace:
 __dump_stack lib/dump_stack.c:82 [inline]
 dump_stack+0xbe/0xfd lib/dump_stack.c:123
 print_address_description.constprop.0+0x1e/0x280 mm/kasan/report.c:400
 __kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560
 kasan_report+0x3a/0x50 mm/kasan/report.c:585
 ext4_xattr_inode_dec_ref_all+0x6ff/0x790 fs/ext4/xattr.c:1137
 ext4_xattr_delete_inode+0x4c7/0xda0 fs/ext4/xattr.c:2896
 ext4_evict_inode+0xb3b/0x1670 fs/ext4/inode.c:323
 evict+0x39f/0x880 fs/inode.c:622
 iput_final fs/inode.c:1746 [inline]
 iput fs/inode.c:1772 [inline]
 iput+0x525/0x6c0 fs/inode.c:1758
 ext4_orphan_cleanup fs/ext4/super.c:3298 [inline]
 ext4_fill_super+0x8c57/0xba40 fs/ext4/super.c:5300
 mount_bdev+0x355/0x410 fs/super.c:1446
 legacy_get_tree+0xfe/0x220 fs/fs_context.c:611
 vfs_get_tree+0x8d/0x2f0 fs/super.c:1576
 do_new_mount fs/namespace.c:2983 [inline]
 path_mount+0x119a/0x1ad0 fs/namespace.c:3316
 do_mount+0xfc/0x110 fs/namespace.c:3329
 __do_sys_mount fs/namespace.c:3540 [inline]
 __se_sys_mount+0x219/0x2e0 fs/namespace.c:3514
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x67/0xd1

Memory state around the buggy address:
 ffff88807b002f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88807b002f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88807b003000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88807b003080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807b003100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

Above issue happens as ext4_xattr_delete_inode() isn't check xattr
is valid if xattr is in inode.
To solve above issue call xattr_check_inode() check if xattr if valid
in inode. In fact, we can directly verify in ext4_iget_extra_inode(),
so that there is no divergent verification.

Fixes: e50e5129f3 ("ext4: xattr-in-inode support")
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250208063141.1539283-3-yebin@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Rajani Kantha <681739313@139.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24 10:35:56 +01:00
Ye Bin
04b1fd7945 ext4: introduce ITAIL helper
[ Upstream commit 69f3a3039b ]

Introduce ITAIL helper to get the bound of xattr in inode.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250208063141.1539283-2-yebin@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Rajani Kantha <681739313@139.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24 10:35:56 +01:00
Julian Sun
1c553d19ff ext4: increase IO priority of fastcommit
[ Upstream commit 46e75c56df ]

The following code paths may result in high latency or even task hangs:
   1. fastcommit io is throttled by wbt.
   2. jbd2_fc_wait_bufs() might wait for a long time while
JBD2_FAST_COMMIT_ONGOING is set in journal->flags, and then
jbd2_journal_commit_transaction() waits for the
JBD2_FAST_COMMIT_ONGOING bit for a long time while holding the write
lock of j_state_lock.
   3. start_this_handle() waits for read lock of j_state_lock which
results in high latency or task hang.

Given the fact that ext4_fc_commit() already modifies the current
process' IO priority to match that of the jbd2 thread, it should be
reasonable to match jbd2's IO submission flags as well.

Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Julian Sun <sunjunchao@bytedance.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-ID: <20250827121812.1477634-1-sunjunchao@bytedance.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-13 15:34:30 -05:00
chuguangqing
238f7a7356 fs: ext4: change GFP_KERNEL to GFP_NOFS to avoid deadlock
[ Upstream commit 1534f72dc2 ]

The parent function ext4_xattr_inode_lookup_create already uses GFP_NOFS for memory alloction, so the function ext4_xattr_inode_cache_find should use same gfp_flag.

Signed-off-by: chuguangqing <chuguangqing@inspur.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-13 15:34:30 -05:00
Deepanshu Kartikey
de985264ee ext4: detect invalid INLINE_DATA + EXTENTS flag combination
commit 1d3ad18394 upstream.

syzbot reported a BUG_ON in ext4_es_cache_extent() when opening a verity
file on a corrupted ext4 filesystem mounted without a journal.

The issue is that the filesystem has an inode with both the INLINE_DATA
and EXTENTS flags set:

    EXT4-fs error (device loop0): ext4_cache_extents:545: inode #15:
    comm syz.0.17: corrupted extent tree: lblk 0 < prev 66

Investigation revealed that the inode has both flags set:
    DEBUG: inode 15 - flag=1, i_inline_off=164, has_inline=1, extents_flag=1

This is an invalid combination since an inode should have either:
- INLINE_DATA: data stored directly in the inode
- EXTENTS: data stored in extent-mapped blocks

Having both flags causes ext4_has_inline_data() to return true, skipping
extent tree validation in __ext4_iget(). The unvalidated out-of-order
extents then trigger a BUG_ON in ext4_es_cache_extent() due to integer
underflow when calculating hole sizes.

Fix this by detecting this invalid flag combination early in ext4_iget()
and rejecting the corrupted inode.

Cc: stable@kernel.org
Reported-and-tested-by: syzbot+038b7bf43423e132b308@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=038b7bf43423e132b308
Suggested-by: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Message-ID: <20250930112810.315095-1-kartikey406@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-23 16:20:19 +02:00
Zhang Yi
5b7b9a1715 ext4: wait for ongoing I/O to complete before freeing blocks
commit 328a782cb1 upstream.

When freeing metadata blocks in nojournal mode, ext4_forget() calls
bforget() to clear the dirty flag on the buffer_head and remvoe
associated mappings. This is acceptable if the metadata has not yet
begun to be written back. However, if the write-back has already started
but is not yet completed, ext4_forget() will have no effect.
Subsequently, ext4_mb_clear_bb() will immediately return the block to
the mb allocator. This block can then be reallocated immediately,
potentially causing an data corruption issue.

Fix this by clearing the buffer's dirty flag and waiting for the ongoing
I/O to complete, ensuring that no further writes to stale data will
occur.

Fixes: 16e08b14a4 ("ext4: cleanup clean_bdev_aliases() calls")
Cc: stable@kernel.org
Reported-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Closes: https://lore.kernel.org/linux-ext4/a9417096-9549-4441-9878-b1955b899b4e@huaweicloud.com/
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-ID: <20250916093337.3161016-3-yi.zhang@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-23 16:20:19 +02:00
Jan Kara
4c0df2938e ext4: free orphan info with kvfree
commit 971843c511 upstream.

Orphan info is now getting allocated with kvmalloc_array(). Free it with
kvfree() instead of kfree() to avoid complaints from mm.

Reported-by: Chris Mason <clm@meta.com>
Fixes: 0a6ce20c15 ("ext4: verify orphan file size is not too big")
Cc: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Message-ID: <20251007134936.7291-2-jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19 16:34:00 +02:00
Deepanshu Kartikey
c7242c71cb ext4: validate ea_ino and size in check_xattrs
commit 44d2a72f4d upstream.

During xattr block validation, check_xattrs() processes xattr entries
without validating that entries claiming to use EA inodes have non-zero
sizes. Corrupted filesystems may contain xattr entries where e_value_size
is zero but e_value_inum is non-zero, indicating invalid xattr data.

Add validation in check_xattrs() to detect this corruption pattern early
and return -EFSCORRUPTED, preventing invalid xattr entries from causing
issues throughout the ext4 codebase.

Cc: stable@kernel.org
Suggested-by: Theodore Ts'o <tytso@mit.edu>
Reported-by: syzbot+4c9d23743a2409b80293@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=4c9d23743a2409b80293
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Message-ID: <20250923133245.1091761-1-kartikey406@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19 16:34:00 +02:00
Ahmet Eray Karadag
6b879c4c6b ext4: guard against EA inode refcount underflow in xattr update
commit 57295e8354 upstream.

syzkaller found a path where ext4_xattr_inode_update_ref() reads an EA
inode refcount that is already <= 0 and then applies ref_change (often
-1). That lets the refcount underflow and we proceed with a bogus value,
triggering errors like:

  EXT4-fs error: EA inode <n> ref underflow: ref_count=-1 ref_change=-1
  EXT4-fs warning: ea_inode dec ref err=-117

Make the invariant explicit: if the current refcount is non-positive,
treat this as on-disk corruption, emit ext4_error_inode(), and fail the
operation with -EFSCORRUPTED instead of updating the refcount. Delete the
WARN_ONCE() as negative refcounts are now impossible; keep error reporting
in ext4_error_inode().

This prevents the underflow and the follow-on orphan/cleanup churn.

Reported-by: syzbot+0be4f339a8218d2a5bb1@syzkaller.appspotmail.com
Fixes: https://syzbot.org/bug?extid=0be4f339a8218d2a5bb1
Cc: stable@kernel.org
Co-developed-by: Albin Babu Varghese <albinbabuvarghese20@gmail.com>
Signed-off-by: Albin Babu Varghese <albinbabuvarghese20@gmail.com>
Signed-off-by: Ahmet Eray Karadag <eraykrdg1@gmail.com>
Message-ID: <20250920021342.45575-1-eraykrdg1@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19 16:33:59 +02:00
Zhang Yi
4c2473d591 ext4: fix an off-by-one issue during moving extents
commit 12e803c882 upstream.

During the movement of a written extent, mext_page_mkuptodate() is
called to read data in the range [from, to) into the page cache and to
update the corresponding buffers. Therefore, we should not wait on any
buffer whose start offset is >= 'to'. Otherwise, it will return -EIO and
fail the extents movement.

 $ for i in `seq 3 -1 0`; \
   do xfs_io -fs -c "pwrite -b 1024 $((i * 1024)) 1024" /mnt/foo; \
   done
 $ umount /mnt && mount /dev/pmem1s /mnt  # drop cache
 $ e4defrag /mnt/foo
   e4defrag 1.47.0 (5-Feb-2023)
   ext4 defragmentation for /mnt/foo
   [1/1]/mnt/foo:    0%    [ NG ]
   Success:                       [0/1]

Cc: stable@kernel.org
Fixes: a40759fb16 ("ext4: remove array of buffer_heads from mext_page_mkuptodate()")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-ID: <20250912105841.1886799-1-yi.zhang@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19 16:33:59 +02:00
Theodore Ts'o
2a0cf43832 ext4: avoid potential buffer over-read in parse_apply_sb_mount_options()
commit 8ecb790ea8 upstream.

Unlike other strings in the ext4 superblock, we rely on tune2fs to
make sure s_mount_opts is NUL terminated.  Harden
parse_apply_sb_mount_options() by treating s_mount_opts as a potential
__nonstring.

Cc: stable@vger.kernel.org
Fixes: 8b67f04ab9 ("ext4: Add mount options in superblock")
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Message-ID: <20250916-tune2fs-v2-1-d594dc7486f0@mit.edu>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19 16:33:59 +02:00
Ojaswin Mujoo
d0327630ec ext4: correctly handle queries for metadata mappings
commit 46c22a8bb4 upstream.

Currently, our handling of metadata is _ambiguous_ in some scenarios,
that is, we end up returning unknown if the range only covers the
mapping partially.

For example, in the following case:

$ xfs_io -c fsmap -d

  0: 254:16 [0..7]: static fs metadata 8
  1: 254:16 [8..15]: special 102:1 8
  2: 254:16 [16..5127]: special 102:2 5112
  3: 254:16 [5128..5255]: special 102:3 128
  4: 254:16 [5256..5383]: special 102:4 128
  5: 254:16 [5384..70919]: inodes 65536
  6: 254:16 [70920..70967]: unknown 48
  ...

$ xfs_io -c fsmap -d 24 33

  0: 254:16 [24..39]: unknown 16  <--- incomplete reporting

$ xfs_io -c fsmap -d 24 33  (With patch)

    0: 254:16 [16..5127]: special 102:2 5112

This is because earlier in ext4_getfsmap_meta_helper, we end up ignoring
any extent that starts before our queried range, but overlaps it. While
the man page [1] is a bit ambiguous on this, this fix makes the output
make more sense since we are anyways returning an "unknown" extent. This
is also consistent to how XFS does it:

$ xfs_io -c fsmap -d

  ...
  6: 254:16 [104..127]: free space 24
  7: 254:16 [128..191]: inodes 64
  ...

$ xfs_io -c fsmap -d 137 150

  0: 254:16 [128..191]: inodes 64   <-- full extent returned

 [1] https://man7.org/linux/man-pages/man2/ioctl_getfsmap.2.html

Reported-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Message-ID: <023f37e35ee280cd9baac0296cbadcbe10995cab.1757058211.git.ojaswin@linux.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19 16:33:59 +02:00
Yongjian Sun
c2ad6583fe ext4: increase i_disksize to offset + len in ext4_update_disksize_before_punch()
commit 9d80eaa1a1 upstream.

After running a stress test combined with fault injection,
we performed fsck -a followed by fsck -fn on the filesystem
image. During the second pass, fsck -fn reported:

Inode 131512, end of extent exceeds allowed value
	(logical block 405, physical block 1180540, len 2)

This inode was not in the orphan list. Analysis revealed the
following call chain that leads to the inconsistency:

                             ext4_da_write_end()
                              //does not update i_disksize
                             ext4_punch_hole()
                              //truncate folio, keep size
ext4_page_mkwrite()
 ext4_block_page_mkwrite()
  ext4_block_write_begin()
    ext4_get_block()
     //insert written extent without update i_disksize
journal commit
echo 1 > /sys/block/xxx/device/delete

da-write path updates i_size but does not update i_disksize. Then
ext4_punch_hole truncates the da-folio yet still leaves i_disksize
unchanged(in the ext4_update_disksize_before_punch function, the
condition offset + len < size is met). Then ext4_page_mkwrite sees
ext4_nonda_switch return 1 and takes the nodioread_nolock path, the
folio about to be written has just been punched out, and it’s offset
sits beyond the current i_disksize. This may result in a written
extent being inserted, but again does not update i_disksize. If the
journal gets committed and then the block device is yanked, we might
run into this. It should be noted that replacing ext4_punch_hole with
ext4_zero_range in the call sequence may also trigger this issue, as
neither will update i_disksize under these circumstances.

To fix this, we can modify ext4_update_disksize_before_punch to
increase i_disksize to min(i_size, offset + len) when both i_size and
(offset + len) are greater than i_disksize.

Cc: stable@kernel.org
Signed-off-by: Yongjian Sun <sunyongjian1@huawei.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Message-ID: <20250911133024.1841027-1-sunyongjian@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19 16:33:59 +02:00
Jan Kara
a2d803fab8 ext4: verify orphan file size is not too big
commit 0a6ce20c15 upstream.

In principle orphan file can be arbitrarily large. However orphan replay
needs to traverse it all and we also pin all its buffers in memory. Thus
filesystems with absurdly large orphan files can lead to big amounts of
memory consumed. Limit orphan file size to a sane value and also use
kvmalloc() for allocating array of block descriptor structures to avoid
large order allocations for sane but large orphan files.

Reported-by: syzbot+0b92850d68d9b12934f5@syzkaller.appspotmail.com
Fixes: 02f310fcf4 ("ext4: Speedup ext4 orphan inode handling")
Cc: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Message-ID: <20250909112206.10459-2-jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19 16:33:59 +02:00
Baokun Li
9169ef838d ext4: add ext4_sb_bread_nofail() helper function for ext4_free_branches()
commit d8b90e6387 upstream.

The implicit __GFP_NOFAIL flag in ext4_sb_bread() was removed in commit
8a83ac5494 ("ext4: call bdev_getblk() from sb_getblk_gfp()"), meaning
the function can now fail under memory pressure.

Most callers of ext4_sb_bread() propagate the error to userspace and do not
remount the filesystem read-only. However, ext4_free_branches() handles
ext4_sb_bread() failure by remounting the filesystem read-only.

This implies that an ext3 filesystem (mounted via the ext4 driver) could be
forcibly remounted read-only due to a transient page allocation failure,
which is unacceptable.

To mitigate this, introduce a new helper function, ext4_sb_bread_nofail(),
which explicitly uses __GFP_NOFAIL, and use it in ext4_free_branches().

Fixes: 8a83ac5494 ("ext4: call bdev_getblk() from sb_getblk_gfp()")
Cc: stable@kernel.org
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19 16:33:59 +02:00
Jan Kara
f50bece98c ext4: fix checks for orphan inodes
commit acf943e976 upstream.

When orphan file feature is enabled, inode can be tracked as orphan
either in the standard orphan list or in the orphan file. The first can
be tested by checking ei->i_orphan list head, the second is recorded by
EXT4_STATE_ORPHAN_FILE inode state flag. There are several places where
we want to check whether inode is tracked as orphan and only some of
them properly check for both possibilities. Luckily the consequences are
mostly minor, the worst that can happen is that we track an inode as
orphan although we don't need to and e2fsck then complains (resulting in
occasional ext4/307 xfstest failures). Fix the problem by introducing a
helper for checking whether an inode is tracked as orphan and use it in
appropriate places.

Fixes: 4a79a98c7b ("ext4: Improve scalability of ext4 orphan file handling")
Cc: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Message-ID: <20250925123038.20264-2-jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-15 12:00:22 +02:00
Theodore Ts'o
aa66603ddf ext4: introduce linear search for dentries
[ Upstream commit 9e28059d56 ]

This patch addresses an issue where some files in case-insensitive
directories become inaccessible due to changes in how the kernel
function, utf8_casefold(), generates case-folded strings from the
commit 5c26d2f1d3 ("unicode: Don't special case ignorable code
points").

There are good reasons why this change should be made; it's actually
quite stupid that Unicode seems to think that the characters ❤ and ❤️
should be casefolded.  Unfortimately because of the backwards
compatibility issue, this commit was reverted in 231825b2e1.

This problem is addressed by instituting a brute-force linear fallback
if a lookup fails on case-folded directory, which does result in a
performance hit when looking up files affected by the changing how
thekernel treats ignorable Uniode characters, or when attempting to
look up non-existent file names.  So this fallback can be disabled by
setting an encoding flag if in the future, the system administrator or
the manufacturer of a mobile handset or tablet can be sure that there
was no opportunity for a kernel to insert file names with incompatible
encodings.

Fixes: 5c26d2f1d3 ("unicode: Don't special case ignorable code points")
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-19 16:35:42 +02:00
Ojaswin Mujoo
eddca44ddf ext4: avoid journaling sb update on error if journal is destroying
commit ce2f26e737 upstream.

Presently we always BUG_ON if trying to start a transaction on a journal marked
with JBD2_UNMOUNT, since this should never happen. However, while ltp running
stress tests, it was observed that in case of some error handling paths, it is
possible for update_super_work to start a transaction after the journal is
destroyed eg:

(umount)
ext4_kill_sb
  kill_block_super
    generic_shutdown_super
      sync_filesystem /* commits all txns */
      evict_inodes
        /* might start a new txn */
      ext4_put_super
	flush_work(&sbi->s_sb_upd_work) /* flush the workqueue */
        jbd2_journal_destroy
          journal_kill_thread
            journal->j_flags |= JBD2_UNMOUNT;
          jbd2_journal_commit_transaction
            jbd2_journal_get_descriptor_buffer
              jbd2_journal_bmap
                ext4_journal_bmap
                  ext4_map_blocks
                    ...
                    ext4_inode_error
                      ext4_handle_error
                        schedule_work(&sbi->s_sb_upd_work)

                                               /* work queue kicks in */
                                               update_super_work
                                                 jbd2_journal_start
                                                   start_this_handle
                                                     BUG_ON(journal->j_flags &
                                                            JBD2_UNMOUNT)

Hence, introduce a new mount flag to indicate journal is destroying and only do
a journaled (and deferred) update of sb if this flag is not set. Otherwise, just
fallback to an un-journaled commit.

Further, in the journal destroy path, we have the following sequence:

  1. Set mount flag indicating journal is destroying
  2. force a commit and wait for it
  3. flush pending sb updates

This sequence is important as it ensures that, after this point, there is no sb
update that might be journaled so it is safe to update the sb outside the
journal. (To avoid race discussed in 2d01ddc866)

Also, we don't need a similar check in ext4_grp_locked_error since it is only
called from mballoc and AFAICT it would be always valid to schedule work here.

Fixes: 2d01ddc866 ("ext4: save error info to sb through journal if available")
Reported-by: Mahesh Kumar <maheshkumar657g@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/9613c465d6ff00cd315602f99283d5f24018c3f7.1742279837.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-09 18:58:20 +02:00
Ojaswin Mujoo
c868e9306e ext4: define ext4_journal_destroy wrapper
commit 5a02a6204c upstream.

Define an ext4 wrapper over jbd2_journal_destroy to make sure we
have consistent behavior during journal destruction. This will also
come useful in the next patch where we add some ext4 specific logic
in the destroy path.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/c3ba78c5c419757e6d5f2d8ebb4a8ce9d21da86a.1742279837.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-09 18:58:20 +02:00
Baokun Li
74482f0005 ext4: preserve SB_I_VERSION on remount
[ Upstream commit f2326fd14a ]

IMA testing revealed that after an ext4 remount, file accesses triggered
full measurements even without modifications, instead of skipping as
expected when i_version is unchanged.

Debugging showed `SB_I_VERSION` was cleared in reconfigure_super() during
remount due to commit 1ff2030739 ("ext4: unconditionally enable the
i_version counter") removing the fix from commit 960e0ab63b ("ext4: fix
i_version handling on remount").

To rectify this, `SB_I_VERSION` is always set for `fc->sb_flags` in
ext4_init_fs_context(), instead of `sb->s_flags` in __ext4_fill_super(),
ensuring it persists across all mounts.

Cc: stable@kernel.org
Fixes: 1ff2030739 ("ext4: unconditionally enable the i_version counter")
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250703073903.6952-2-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[ Adjust context ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:07 +02:00
Zhang Yi
275c88b797 ext4: fix hole length calculation overflow in non-extent inodes
commit 02c7f7219a upstream.

In a filesystem with a block size larger than 4KB, the hole length
calculation for a non-extent inode in ext4_ind_map_blocks() can easily
exceed INT_MAX. Then it could return a zero length hole and trigger the
following waring and infinite in the iomap infrastructure.

  ------------[ cut here ]------------
  WARNING: CPU: 3 PID: 434101 at fs/iomap/iter.c:34 iomap_iter_done+0x148/0x190
  CPU: 3 UID: 0 PID: 434101 Comm: fsstress Not tainted 6.16.0-rc7+ #128 PREEMPT(voluntary)
  Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022
  pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : iomap_iter_done+0x148/0x190
  lr : iomap_iter+0x174/0x230
  sp : ffff8000880af740
  x29: ffff8000880af740 x28: ffff0000db8e6840 x27: 0000000000000000
  x26: 0000000000000000 x25: ffff8000880af830 x24: 0000004000000000
  x23: 0000000000000002 x22: 000001bfdbfa8000 x21: ffffa6a41c002e48
  x20: 0000000000000001 x19: ffff8000880af808 x18: 0000000000000000
  x17: 0000000000000000 x16: ffffa6a495ee6cd0 x15: 0000000000000000
  x14: 00000000000003d4 x13: 00000000fa83b2da x12: 0000b236fc95f18c
  x11: ffffa6a4978b9c08 x10: 0000000000001da0 x9 : ffffa6a41c1a2a44
  x8 : ffff8000880af5c8 x7 : 0000000001000000 x6 : 0000000000000000
  x5 : 0000000000000004 x4 : 000001bfdbfa8000 x3 : 0000000000000000
  x2 : 0000000000000000 x1 : 0000004004030000 x0 : 0000000000000000
  Call trace:
   iomap_iter_done+0x148/0x190 (P)
   iomap_iter+0x174/0x230
   iomap_fiemap+0x154/0x1d8
   ext4_fiemap+0x110/0x140 [ext4]
   do_vfs_ioctl+0x4b8/0xbc0
   __arm64_sys_ioctl+0x8c/0x120
   invoke_syscall+0x6c/0x100
   el0_svc_common.constprop.0+0x48/0xf0
   do_el0_svc+0x24/0x38
   el0_svc+0x38/0x120
   el0t_64_sync_handler+0x10c/0x138
   el0t_64_sync+0x198/0x1a0
  ---[ end trace 0000000000000000 ]---

Cc: stable@kernel.org
Fixes: facab4d971 ("ext4: return hole from ext4_map_blocks()")
Reported-by: Qu Wenruo <wqu@suse.com>
Closes: https://lore.kernel.org/linux-ext4/9b650a52-9672-4604-a765-bb6be55d1e4a@gmx.com/
Tested-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250811064532.1788289-1-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:30:56 +02:00
Liao Yuanhong
e767e51cae ext4: use kmalloc_array() for array space allocation
commit 76dba1fe27 upstream.

Replace kmalloc(size * sizeof) with kmalloc_array() for safer memory
allocation and overflow prevention.

Cc: stable@kernel.org
Signed-off-by: Liao Yuanhong <liaoyuanhong@vivo.com>
Link: https://patch.msgid.link/20250811125816.570142-1-liaoyuanhong@vivo.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:30:56 +02:00
Theodore Ts'o
48a6128a4a ext4: don't try to clear the orphan_present feature block device is r/o
commit c5e104a91e upstream.

When the file system is frozen in preparation for taking an LVM
snapshot, the journal is checkpointed and if the orphan_file feature
is enabled, and the orphan file is empty, we clear the orphan_present
feature flag.  But if there are pending inodes that need to be removed
the orphan_present feature flag can't be cleared.

The problem comes if the block device is read-only.  In that case, we
can't process the orphan inode list, so it is skipped in
ext4_orphan_cleanup().  But then in ext4_mark_recovery_complete(),
this results in the ext4 error "Orphan file not empty on read-only fs"
firing and the file system mount is aborted.

Fix this by clearing the needs_recovery flag in the block device is
read-only.  We do this after the call to ext4_load_and_init-journal()
since there are some error checks need to be done in case the journal
needs to be replayed and the block device is read-only, or if the
block device containing the externa journal is read-only, etc.

Cc: stable@kernel.org
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1108271
Cc: stable@vger.kernel.org
Fixes: 02f310fcf4 ("ext4: Speedup ext4 orphan inode handling")
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:30:56 +02:00
Ojaswin Mujoo
0bbcd9434c ext4: fix reserved gdt blocks handling in fsmap
commit 3ffbdd1f11 upstream.

In some cases like small FSes with no meta_bg and where the resize
doesn't need extra gdt blocks as it can fit in the current one,
s_reserved_gdt_blocks is set as 0, which causes fsmap to emit a 0
length entry, which is incorrect.

  $ mkfs.ext4 -b 65536 -O bigalloc /dev/sda 5G
  $ mount /dev/sda /mnt/scratch
  $ xfs_io -c "fsmap -d" /mnt/scartch

        0: 253:48 [0..127]: static fs metadata 128
        1: 253:48 [128..255]: special 102:1 128
        2: 253:48 [256..255]: special 102:2 0     <---- 0 len entry
        3: 253:48 [256..383]: special 102:3 128

Fix this by adding a check for this case.

Cc: stable@kernel.org
Fixes: 0c9ec4beec ("ext4: support GETFSMAP ioctls")
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://patch.msgid.link/08781b796453a5770112aa96ad14c864fbf31935.1754377641.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:30:56 +02:00
Ojaswin Mujoo
4fa1098957 ext4: fix fsmap end of range reporting with bigalloc
commit bae76c035b upstream.

With bigalloc enabled, the logic to report last extent has a bug since
we try to use cluster units instead of block units. This can cause an
issue where extra incorrect entries might be returned back to the
user. This was flagged by generic/365 with 64k bs and -O bigalloc.

** Details of issue **

The issue was noticed on 5G 64k blocksize FS with -O bigalloc which has
only 1 bg.

$ xfs_io -c "fsmap -d" /mnt/scratch

  0: 253:48 [0..127]: static fs metadata 128   /* sb */
  1: 253:48 [128..255]: special 102:1 128   /* gdt */
  3: 253:48 [256..383]: special 102:3 128   /* block bitmap */
  4: 253:48 [384..2303]: unknown 1920       /* flex bg empty space */
  5: 253:48 [2304..2431]: special 102:4 128   /* inode bitmap */
  6: 253:48 [2432..4351]: unknown 1920      /* flex bg empty space */
  7: 253:48 [4352..6911]: inodes 2560
  8: 253:48 [6912..538623]: unknown 531712
  9: 253:48 [538624..10485759]: free space 9947136

The issue can be seen with:

$ xfs_io -c "fsmap -d 0 3" /mnt/scratch

  0: 253:48 [0..127]: static fs metadata 128
  1: 253:48 [384..2047]: unknown 1664

Only the first entry was expected to be returned but we get 2. This is
because:

ext4_getfsmap_datadev()
  first_cluster, last_cluster = 0
  ...
  info->gfi_last = true;
  ext4_getfsmap_datadev_helper(sb, end_ag, last_cluster + 1, 0, info);
    fsb = C2B(1) = 16
    fslen = 0
    ...
    /* Merge in any relevant extents from the meta_list */
    list_for_each_entry_safe(p, tmp, &info->gfi_meta_list, fmr_list) {
      ...
      // since fsb = 16, considers all metadata which starts before 16 blockno
      iter 1: error = ext4_getfsmap_helper(sb, info, p);  // p = sb (0,1), nop
        info->gfi_next_fsblk = 1
      iter 2: error = ext4_getfsmap_helper(sb, info, p);  // p = gdt (1,2), nop
        info->gfi_next_fsblk = 2
      iter 3: error = ext4_getfsmap_helper(sb, info, p);  // p = blk bitmap (2,3), nop
        info->gfi_next_fsblk = 3
      iter 4: error = ext4_getfsmap_helper(sb, info, p);  // p = ino bitmap (18,19)
        if (rec_blk > info->gfi_next_fsblk) { // (18 > 3)
          // emits an extra entry ** BUG **
        }
    }

Fix this by directly calling ext4_getfsmap_datadev() with a dummy
record that has fmr_physical set to (end_fsb + 1) instead of
last_cluster + 1. By using the block instead of cluster we get the
correct behavior.

Replacing ext4_getfsmap_datadev_helper() with ext4_getfsmap_helper()
is okay since the gfi_lastfree and metadata checks in
ext4_getfsmap_datadev_helper() are anyways redundant when we only want
to emit the last allocated block of the range, as we have already
taken care of emitting metadata and any last free blocks.

Cc: stable@kernel.org
Reported-by: Disha Goel <disgoel@linux.ibm.com>
Fixes: 4a622e4d47 ("ext4: fix FS_IOC_GETFSMAP handling")
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://patch.msgid.link/e7472c8535c9c5ec10f425f495366864ea12c9da.1754377641.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:30:56 +02:00
Andreas Dilger
14cfb25eaf ext4: check fast symlink for ea_inode correctly
commit b4cc4a4077 upstream.

The check for a fast symlink in the presence of only an
external xattr inode is incorrect.  If a fast symlink does
not have an xattr block (i_file_acl == 0), but does have
an external xattr inode that increases inode i_blocks, then
the check for a fast symlink will incorrectly fail and
__ext4_iget()->ext4_ind_check_inode() will report the inode
is corrupt when it "validates" i_data[] on the next read:

    # ln -s foo /mnt/tmp/bar
    # setfattr -h -n trusted.test \
               -v "$(yes | head -n 4000)" /mnt/tmp/bar
    # umount /mnt/tmp
    # mount /mnt/tmp
    # ls -l /mnt/tmp
    ls: cannot access '/mnt/tmp/bar': Structure needs cleaning
    total 4
     ? l?????????? ? ?    ?        ?            ? bar
    # dmesg | tail -1
    EXT4-fs error (device dm-8): __ext4_iget:5098:
        inode #24578: block 7303014: comm ls: invalid block

(note that "block 7303014" = 0x6f6f66 = "foo" in LE order).

ext4_inode_is_fast_symlink() should check the superblock
EXT4_FEATURE_INCOMPAT_EA_INODE feature flag, not the inode
EXT4_EA_INODE_FL, since the latter is only set on the xattr
inode itself, and not on the inode that uses this xattr.

Cc: stable@vger.kernel.org
Fixes: fc82228a5e ("ext4: support fast symlinks from ext3 file systems")
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Li Dongyang <dongyangli@ddn.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/59879
Lustre-bug-id: https://jira.whamcloud.com/browse/LU-19121
Link: https://patch.msgid.link/20250717063709.757077-1-adilger@dilger.ca
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:30:55 +02:00
Zhang Yi
a2bbe1fcd3 ext4: initialize superblock fields in the kballoc-test.c kunit tests
commit 82e6381e23 upstream.

Various changes in the "ext4: better scalability for ext4 block
allocation" patch series have resulted in kunit test failures, most
notably in the test_new_blocks_simple and the test_mb_mark_used tests.
The root cause of these failures is that various in-memory ext4 data
structures were not getting initialized, and while previous versions
of the functions exercised by the unit tests didn't use these
structure members, this was arguably a test bug.

Since one of the patches in the block allocation scalability patches
is a fix which is has a cc:stable tag, this commit also has a
cc:stable tag.

CC: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250714130327.1830534-1-libaokun1@huawei.com
Link: https://patch.msgid.link/20250725021550.3177573-1-yi.zhang@huaweicloud.com
Link: https://patch.msgid.link/20250725021654.3188798-1-yi.zhang@huaweicloud.com
Reported-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/linux-ext4/b0635ad0-7ebf-4152-a69b-58e7e87d5085@roeck-us.net/
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:52 +02:00
Baokun Li
c0d7c98272 ext4: fix largest free orders lists corruption on mb_optimize_scan switch
commit 7d345aa1fa upstream.

The grp->bb_largest_free_order is updated regardless of whether
mb_optimize_scan is enabled. This can lead to inconsistencies between
grp->bb_largest_free_order and the actual s_mb_largest_free_orders list
index when mb_optimize_scan is repeatedly enabled and disabled via remount.

For example, if mb_optimize_scan is initially enabled, largest free
order is 3, and the group is in s_mb_largest_free_orders[3]. Then,
mb_optimize_scan is disabled via remount, block allocations occur,
updating largest free order to 2. Finally, mb_optimize_scan is re-enabled
via remount, more block allocations update largest free order to 1.

At this point, the group would be removed from s_mb_largest_free_orders[3]
under the protection of s_mb_largest_free_orders_locks[2]. This lock
mismatch can lead to list corruption.

To fix this, whenever grp->bb_largest_free_order changes, we now always
attempt to remove the group from its old order list. However, we only
insert the group into the new order list if `mb_optimize_scan` is enabled.
This approach helps prevent lock inconsistencies and ensures the data in
the order lists remains reliable.

Fixes: 196e402adf ("ext4: improve cr 0 / cr 1 group scanning")
CC: stable@vger.kernel.org
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250714130327.1830534-12-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:52 +02:00
Baokun Li
9dc75a54c0 ext4: fix zombie groups in average fragment size lists
commit 1c320d8e92 upstream.

Groups with no free blocks shouldn't be in any average fragment size list.
However, when all blocks in a group are allocated(i.e., bb_fragments or
bb_free is 0), we currently skip updating the average fragment size, which
means the group isn't removed from its previous s_mb_avg_fragment_size[old]
list.

This created "zombie" groups that were always skipped during traversal as
they couldn't satisfy any block allocation requests, negatively impacting
traversal efficiency.

Therefore, when a group becomes completely full, bb_avg_fragment_size_order
is now set to -1. If the old order was not -1, a removal operation is
performed; if the new order is not -1, an insertion is performed.

Fixes: 196e402adf ("ext4: improve cr 0 / cr 1 group scanning")
CC: stable@vger.kernel.org
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250714130327.1830534-11-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:52 +02:00
Theodore Ts'o
81e7e2e7ba ext4: do not BUG when INLINE_DATA_FL lacks system.data xattr
[ Upstream commit 099b847ccc ]

A syzbot fuzzed image triggered a BUG_ON in ext4_update_inline_data()
when an inode had the INLINE_DATA_FL flag set but was missing the
system.data extended attribute.

Since this can happen due to a maiciouly fuzzed file system, we
shouldn't BUG, but rather, report it as a corrupted file system.

Add similar replacements of BUG_ON with EXT4_ERROR_INODE() ii
ext4_create_inline_data() and ext4_inline_data_truncate().

Reported-by: syzbot+544248a761451c0df72f@syzkaller.appspotmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-20 18:30:41 +02:00
Jan Kara
b2e294216b ext4: Make sure BH_New bit is cleared in ->write_end handler
[ Upstream commit 91b8ca8b26 ]

Currently we clear BH_New bit in case of error and also in the standard
ext4_write_end() handler (in block_commit_write()). However
ext4_journalled_write_end() misses this clearing and thus we are leaving
stale BH_New bits behind. Generally ext4_block_write_begin() clears
these bits before any harm can be done but in case blocksize < pagesize
and we hit some error when processing a page with these stale bits,
we'll try to zero buffers with these stale BH_New bits and jbd2 will
complain (as buffers were not prepared for writing in this transaction).
Fix the problem by clearing BH_New bits in ext4_journalled_write_end()
and WARN if ext4_block_write_begin() sees stale BH_New bits.

Reported-by: Baolin Liu <liubaolin12138@163.com>
Reported-by: Zhi Long <longzhi@sangfor.com.cn>
Fixes: 3910b513fc ("ext4: persist the new uptodate buffers in ext4_journalled_zero_new_buffers")
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250709084831.23876-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15 12:13:55 +02:00
Zhang Yi
a4d60ba277 ext4: fix out of bounds punch offset
[ Upstream commit b5e58bcd79 ]

Punching a hole with a start offset that exceeds max_end is not
permitted and will result in a negative length in the
truncate_inode_partial_folio() function while truncating the page cache,
potentially leading to undesirable consequences.

A simple reproducer:

  truncate -s 9895604649994 /mnt/foo
  xfs_io -c "pwrite 8796093022208 4096" /mnt/foo
  xfs_io -c "fpunch 8796093022213 25769803777" /mnt/foo

  kernel BUG at include/linux/highmem.h:275!
  Oops: invalid opcode: 0000 [#1] SMP PTI
  CPU: 3 UID: 0 PID: 710 Comm: xfs_io Not tainted 6.15.0-rc3
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
  RIP: 0010:zero_user_segments.constprop.0+0xd7/0x110
  RSP: 0018:ffffc90001cf3b38 EFLAGS: 00010287
  RAX: 0000000000000005 RBX: ffffea0001485e40 RCX: 0000000000001000
  RDX: 000000000040b000 RSI: 0000000000000005 RDI: 000000000040b000
  RBP: 000000000040affb R08: ffff888000000000 R09: ffffea0000000000
  R10: 0000000000000003 R11: 00000000fffc7fc5 R12: 0000000000000005
  R13: 000000000040affb R14: ffffea0001485e40 R15: ffff888031cd3000
  FS:  00007f4f63d0b780(0000) GS:ffff8880d337d000(0000)
  knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 000000001ae0b038 CR3: 00000000536aa000 CR4: 00000000000006f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <TASK>
   truncate_inode_partial_folio+0x3dd/0x620
   truncate_inode_pages_range+0x226/0x720
   ? bdev_getblk+0x52/0x3e0
   ? ext4_get_group_desc+0x78/0x150
   ? crc32c_arch+0xfd/0x180
   ? __ext4_get_inode_loc+0x18c/0x840
   ? ext4_inode_csum+0x117/0x160
   ? jbd2_journal_dirty_metadata+0x61/0x390
   ? __ext4_handle_dirty_metadata+0xa0/0x2b0
   ? kmem_cache_free+0x90/0x5a0
   ? jbd2_journal_stop+0x1d5/0x550
   ? __ext4_journal_stop+0x49/0x100
   truncate_pagecache_range+0x50/0x80
   ext4_truncate_page_cache_block_range+0x57/0x3a0
   ext4_punch_hole+0x1fe/0x670
   ext4_fallocate+0x792/0x17d0
   ? __count_memcg_events+0x175/0x2a0
   vfs_fallocate+0x121/0x560
   ksys_fallocate+0x51/0xc0
   __x64_sys_fallocate+0x24/0x40
   x64_sys_call+0x18d2/0x4170
   do_syscall_64+0xa7/0x220
   entry_SYSCALL_64_after_hwframe+0x76/0x7e

Fix this by filtering out cases where the punching start offset exceeds
max_end.

Fixes: 982bf37da0 ("ext4: refactor ext4_punch_hole()")
Reported-by: Liebes Wang <wanghaichi0403@gmail.com>
Closes: https://lore.kernel.org/linux-ext4/ac3a58f6-e686-488b-a9ee-fc041024e43d@huawei.com/
Tested-by: Liebes Wang <wanghaichi0403@gmail.com>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250506012009.3896990-1-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-01 09:48:46 +01:00
Zhang Yi
51492e9989 ext4: correct the error handle in ext4_fallocate()
[ Upstream commit 129245cfbd ]

The error out label of file_modified() should be out_inode_lock in
ext4_fallocate().

Fixes: 2890e5e0f4 ("ext4: move out common parts into ext4_fallocate()")
Reported-by: Baokun Li <libaokun1@huawei.com>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250319023557.2785018-1-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-01 09:48:46 +01:00
Zhang Yi
85defb9933 ext4: fix incorrect punch max_end
[ Upstream commit 29ec9bed23 ]

For the extents based inodes, the maxbytes should be sb->s_maxbytes
instead of sbi->s_bitmap_maxbytes. Additionally, for the calculation of
max_end, the -sb->s_blocksize operation is necessary only for
indirect-block based inodes. Correct the maxbytes and max_end value to
correct the behavior of punch hole.

Fixes: 2da376228a ("ext4: limit length to bitmap_maxbytes - blocksize in punch_hole")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250506012009.3896990-2-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-01 09:48:46 +01:00
Zhang Yi
35bd33e3ef ext4: move out common parts into ext4_fallocate()
[ Upstream commit 2890e5e0f4 ]

Currently, all zeroing ranges, punch holes, collapse ranges, and insert
ranges first wait for all existing direct I/O workers to complete, and
then they acquire the mapping's invalidate lock before performing the
actual work. These common components are nearly identical, so we can
simplify the code by factoring them out into the ext4_fallocate().

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20241220011637.1157197-11-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 29ec9bed23 ("ext4: fix incorrect punch max_end")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-01 09:48:46 +01:00
Zhang Yi
8a98313caa ext4: move out inode_lock into ext4_fallocate()
[ Upstream commit ea3f17efd3 ]

Currently, all five sub-functions of ext4_fallocate() acquire the
inode's i_rwsem at the beginning and release it before exiting. This
process can be simplified by factoring out the management of i_rwsem
into the ext4_fallocate() function.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20241220011637.1157197-10-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 29ec9bed23 ("ext4: fix incorrect punch max_end")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-01 09:48:46 +01:00
Zhang Yi
1697ca500a ext4: factor out ext4_do_fallocate()
[ Upstream commit fd2f764826 ]

Now the real job of normal fallocate are open coded in ext4_fallocate(),
factor out a new helper ext4_do_fallocate() to do the real job, like
others functions (e.g. ext4_zero_range()) in ext4_fallocate() do, this
can make the code more clear, no functional changes.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20241220011637.1157197-9-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 29ec9bed23 ("ext4: fix incorrect punch max_end")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-01 09:48:45 +01:00
Zhang Yi
2cbc4d640d ext4: refactor ext4_insert_range()
[ Upstream commit 4942550437 ]

Simplify ext4_insert_range() and align its code style with that of
ext4_collapse_range(). Refactor it by: a) renaming variables, b)
removing redundant input parameter checks and moving the remaining
checks under i_rwsem in preparation for future refactoring, and c)
renaming the three stale error tags.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20241220011637.1157197-8-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 29ec9bed23 ("ext4: fix incorrect punch max_end")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-01 09:48:45 +01:00
Zhang Yi
8bb93d9882 ext4: refactor ext4_collapse_range()
[ Upstream commit 162e3c5ad1 ]

Simplify ext4_collapse_range() and align its code style with that of
ext4_zero_range() and ext4_punch_hole(). Refactor it by: a) renaming
variables, b) removing redundant input parameter checks and moving
the remaining checks under i_rwsem in preparation for future
refactoring, and c) renaming the three stale error tags.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20241220011637.1157197-7-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 29ec9bed23 ("ext4: fix incorrect punch max_end")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-01 09:48:45 +01:00
Zhang Yi
db1fcf7fd5 ext4: refactor ext4_zero_range()
[ Upstream commit 53471e0bed ]

The current implementation of ext4_zero_range() contains complex
position calculations and stale error tags. To improve the code's
clarity and maintainability, it is essential to clean up the code and
improve its readability, this can be achieved by: a) simplifying and
renaming variables, making the style the same as ext4_punch_hole(); b)
eliminating unnecessary position calculations, writing back all data in
data=journal mode, and drop page cache from the original offset to the
end, rather than using aligned blocks; c) renaming the stale out_mutex
tags.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20241220011637.1157197-6-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 29ec9bed23 ("ext4: fix incorrect punch max_end")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-01 09:48:45 +01:00
Zhang Yi
33f61ecabb ext4: refactor ext4_punch_hole()
[ Upstream commit 982bf37da0 ]

The current implementation of ext4_punch_hole() contains complex
position calculations and stale error tags. To improve the code's
clarity and maintainability, it is essential to clean up the code and
improve its readability, this can be achieved by: a) simplifying and
renaming variables; b) eliminating unnecessary position calculations;
c) writing back all data in data=journal mode, and drop page cache from
the original offset to the end, rather than using aligned blocks,
d) renaming the stale error tags.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20241220011637.1157197-5-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 29ec9bed23 ("ext4: fix incorrect punch max_end")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-01 09:48:45 +01:00
Zhang Yi
d9116d2853 ext4: don't explicit update times in ext4_fallocate()
[ Upstream commit 73ae756ecd ]

After commit 'ad5cd4f4ee ("ext4: fix fallocate to use file_modified to
update permissions consistently"), we can update mtime and ctime
appropriately through file_modified() when doing zero range, collapse
rage, insert range and punch hole, hence there is no need to explicit
update times in those paths, just drop them.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20241220011637.1157197-3-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 29ec9bed23 ("ext4: fix incorrect punch max_end")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-01 09:48:45 +01:00
Brian Foster
be5f3061a6 ext4: only dirty folios when data journaling regular files
commit e26268ff1d upstream.

fstest generic/388 occasionally reproduces a crash that looks as
follows:

BUG: kernel NULL pointer dereference, address: 0000000000000000
...
Call Trace:
 <TASK>
 ext4_block_zero_page_range+0x30c/0x380 [ext4]
 ext4_truncate+0x436/0x440 [ext4]
 ext4_process_orphan+0x5d/0x110 [ext4]
 ext4_orphan_cleanup+0x124/0x4f0 [ext4]
 ext4_fill_super+0x262d/0x3110 [ext4]
 get_tree_bdev_flags+0x132/0x1d0
 vfs_get_tree+0x26/0xd0
 vfs_cmd_create+0x59/0xe0
 __do_sys_fsconfig+0x4ed/0x6b0
 do_syscall_64+0x82/0x170
 ...

This occurs when processing a symlink inode from the orphan list. The
partial block zeroing code in the truncate path calls
ext4_dirty_journalled_data() -> folio_mark_dirty(). The latter calls
mapping->a_ops->dirty_folio(), but symlink inodes are not assigned an
a_ops vector in ext4, hence the crash.

To avoid this problem, update the ext4_dirty_journalled_data() helper to
only mark the folio dirty on regular files (for which a_ops is
assigned). This also matches the journaling logic in the ext4_symlink()
creation path, where ext4_handle_dirty_metadata() is called directly.

Fixes: d84c9ebdac ("ext4: Mark pages with journalled data dirty")
Signed-off-by: Brian Foster <bfoster@redhat.com>
Link: https://patch.msgid.link/20250516173800.175577-1-bfoster@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27 11:11:20 +01:00
Zhang Yi
4b36399711 ext4: ensure i_size is smaller than maxbytes
commit 1a77a028a3 upstream.

The inode i_size cannot be larger than maxbytes, check it while loading
inode from the disk.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250506012009.3896990-4-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27 11:11:20 +01:00
Zhang Yi
b841ca8c8f ext4: factor out ext4_get_maxbytes()
commit dbe27f06fa upstream.

There are several locations that get the correct maxbytes value based on
the inode's block type. It would be beneficial to extract a common
helper function to make the code more clear.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250506012009.3896990-3-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27 11:11:20 +01:00
Jan Kara
796632e6f8 ext4: fix calculation of credits for extent tree modification
commit 32a93f5bc9 upstream.

Luis and David are reporting that after running generic/750 test for 90+
hours on 2k ext4 filesystem, they are able to trigger a warning in
jbd2_journal_dirty_metadata() complaining that there are not enough
credits in the running transaction started in ext4_do_writepages().

Indeed the code in ext4_do_writepages() is racy and the extent tree can
change between the time we compute credits necessary for extent tree
computation and the time we actually modify the extent tree. Thus it may
happen that the number of credits actually needed is higher. Modify
ext4_ext_index_trans_blocks() to count with the worst case of maximum
tree depth. This can reduce the possible number of writers that can
operate in the system in parallel (because the credit estimates now won't
fit in one transaction) but for reasonably sized journals this shouldn't
really be an issue. So just go with a safe and simple fix.

Link: https://lore.kernel.org/all/20250415013641.f2ppw6wov4kn4wq2@offworld
Reported-by: Davidlohr Bueso <dave@stgolabs.net>
Reported-by: Luis Chamberlain <mcgrof@kernel.org>
Tested-by: kdevops@lists.linux.dev
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250429175535.23125-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27 11:11:20 +01:00
Thadeu Lima de Souza Cascardo
5766da2237 ext4: inline: fix len overflow in ext4_prepare_inline_data
commit 227cb4ca5a upstream.

When running the following code on an ext4 filesystem with inline_data
feature enabled, it will lead to the bug below.

        fd = open("file1", O_RDWR | O_CREAT | O_TRUNC, 0666);
        ftruncate(fd, 30);
        pwrite(fd, "a", 1, (1UL << 40) + 5UL);

That happens because write_begin will succeed as when
ext4_generic_write_inline_data calls ext4_prepare_inline_data, pos + len
will be truncated, leading to ext4_prepare_inline_data parameter to be 6
instead of 0x10000000006.

Then, later when write_end is called, we hit:

        BUG_ON(pos + len > EXT4_I(inode)->i_inline_size);

at ext4_write_inline_data.

Fix it by using a loff_t type for the len parameter in
ext4_prepare_inline_data instead of an unsigned int.

[   44.545164] ------------[ cut here ]------------
[   44.545530] kernel BUG at fs/ext4/inline.c:240!
[   44.545834] Oops: invalid opcode: 0000 [#1] SMP NOPTI
[   44.546172] CPU: 3 UID: 0 PID: 343 Comm: test Not tainted 6.15.0-rc2-00003-g9080916f4863 #45 PREEMPT(full)  112853fcebfdb93254270a7959841d2c6aa2c8bb
[   44.546523] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   44.546523] RIP: 0010:ext4_write_inline_data+0xfe/0x100
[   44.546523] Code: 3c 0e 48 83 c7 48 48 89 de 5b 41 5c 41 5d 41 5e 41 5f 5d e9 e4 fa 43 01 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 0f 0b <0f> 0b 0f 1f 44 00 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 20 49
[   44.546523] RSP: 0018:ffffb342008b79a8 EFLAGS: 00010216
[   44.546523] RAX: 0000000000000001 RBX: ffff9329c579c000 RCX: 0000010000000006
[   44.546523] RDX: 000000000000003c RSI: ffffb342008b79f0 RDI: ffff9329c158e738
[   44.546523] RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
[   44.546523] R10: 00007ffffffff000 R11: ffffffff9bd0d910 R12: 0000006210000000
[   44.546523] R13: fffffc7e4015e700 R14: 0000010000000005 R15: ffff9329c158e738
[   44.546523] FS:  00007f4299934740(0000) GS:ffff932a60179000(0000) knlGS:0000000000000000
[   44.546523] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   44.546523] CR2: 00007f4299a1ec90 CR3: 0000000002886002 CR4: 0000000000770eb0
[   44.546523] PKRU: 55555554
[   44.546523] Call Trace:
[   44.546523]  <TASK>
[   44.546523]  ext4_write_inline_data_end+0x126/0x2d0
[   44.546523]  generic_perform_write+0x17e/0x270
[   44.546523]  ext4_buffered_write_iter+0xc8/0x170
[   44.546523]  vfs_write+0x2be/0x3e0
[   44.546523]  __x64_sys_pwrite64+0x6d/0xc0
[   44.546523]  do_syscall_64+0x6a/0xf0
[   44.546523]  ? __wake_up+0x89/0xb0
[   44.546523]  ? xas_find+0x72/0x1c0
[   44.546523]  ? next_uptodate_folio+0x317/0x330
[   44.546523]  ? set_pte_range+0x1a6/0x270
[   44.546523]  ? filemap_map_pages+0x6ee/0x840
[   44.546523]  ? ext4_setattr+0x2fa/0x750
[   44.546523]  ? do_pte_missing+0x128/0xf70
[   44.546523]  ? security_inode_post_setattr+0x3e/0xd0
[   44.546523]  ? ___pte_offset_map+0x19/0x100
[   44.546523]  ? handle_mm_fault+0x721/0xa10
[   44.546523]  ? do_user_addr_fault+0x197/0x730
[   44.546523]  ? do_syscall_64+0x76/0xf0
[   44.546523]  ? arch_exit_to_user_mode_prepare+0x1e/0x60
[   44.546523]  ? irqentry_exit_to_user_mode+0x79/0x90
[   44.546523]  entry_SYSCALL_64_after_hwframe+0x55/0x5d
[   44.546523] RIP: 0033:0x7f42999c6687
[   44.546523] Code: 48 89 fa 4c 89 df e8 58 b3 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
[   44.546523] RSP: 002b:00007ffeae4a7930 EFLAGS: 00000202 ORIG_RAX: 0000000000000012
[   44.546523] RAX: ffffffffffffffda RBX: 00007f4299934740 RCX: 00007f42999c6687
[   44.546523] RDX: 0000000000000001 RSI: 000055ea6149200f RDI: 0000000000000003
[   44.546523] RBP: 00007ffeae4a79a0 R08: 0000000000000000 R09: 0000000000000000
[   44.546523] R10: 0000010000000005 R11: 0000000000000202 R12: 0000000000000000
[   44.546523] R13: 00007ffeae4a7ac8 R14: 00007f4299b86000 R15: 000055ea61493dd8
[   44.546523]  </TASK>
[   44.546523] Modules linked in:
[   44.568501] ---[ end trace 0000000000000000 ]---
[   44.568889] RIP: 0010:ext4_write_inline_data+0xfe/0x100
[   44.569328] Code: 3c 0e 48 83 c7 48 48 89 de 5b 41 5c 41 5d 41 5e 41 5f 5d e9 e4 fa 43 01 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 0f 0b <0f> 0b 0f 1f 44 00 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 20 49
[   44.570931] RSP: 0018:ffffb342008b79a8 EFLAGS: 00010216
[   44.571356] RAX: 0000000000000001 RBX: ffff9329c579c000 RCX: 0000010000000006
[   44.571959] RDX: 000000000000003c RSI: ffffb342008b79f0 RDI: ffff9329c158e738
[   44.572571] RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
[   44.573148] R10: 00007ffffffff000 R11: ffffffff9bd0d910 R12: 0000006210000000
[   44.573748] R13: fffffc7e4015e700 R14: 0000010000000005 R15: ffff9329c158e738
[   44.574335] FS:  00007f4299934740(0000) GS:ffff932a60179000(0000) knlGS:0000000000000000
[   44.575027] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   44.575520] CR2: 00007f4299a1ec90 CR3: 0000000002886002 CR4: 0000000000770eb0
[   44.576112] PKRU: 55555554
[   44.576338] Kernel panic - not syncing: Fatal exception
[   44.576517] Kernel Offset: 0x1a600000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)

Reported-by: syzbot+fe2a25dae02a207717a0@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=fe2a25dae02a207717a0
Fixes: f19d5870cb ("ext4: add normal write support for inline data")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://patch.msgid.link/20250415-ext4-prepare-inline-overflow-v1-1-f4c13d900967@igalia.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27 11:11:20 +01:00
Zhang Yi
2a25d61107 ext4: remove writable userspace mappings before truncating page cache
[ Upstream commit 17207d0bb2 ]

When zeroing a range of folios on the filesystem which block size is
less than the page size, the file's mapped blocks within one page will
be marked as unwritten, we should remove writable userspace mappings to
ensure that ext4_page_mkwrite() can be called during subsequent write
access to these partial folios. Otherwise, data written by subsequent
mmap writes may not be saved to disk.

 $mkfs.ext4 -b 1024 /dev/vdb
 $mount /dev/vdb /mnt
 $xfs_io -t -f -c "pwrite -S 0x58 0 4096" -c "mmap -rw 0 4096" \
               -c "mwrite -S 0x5a 2048 2048" -c "fzero 2048 2048" \
               -c "mwrite -S 0x59 2048 2048" -c "close" /mnt/foo

 $od -Ax -t x1z /mnt/foo
 000000 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58
 *
 000800 59 59 59 59 59 59 59 59 59 59 59 59 59 59 59 59
 *
 001000

 $umount /mnt && mount /dev/vdb /mnt
 $od -Ax -t x1z /mnt/foo
 000000 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58
 *
 000800 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 *
 001000

Fix this by introducing ext4_truncate_page_cache_block_range() to remove
writable userspace mappings when truncating a partial folio range.
Additionally, move the journal data mode-specific handlers and
truncate_pagecache_range() into this function, allowing it to serve as a
common helper that correctly manages the page cache in preparation for
block range manipulations.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20241220011637.1157197-2-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-29 11:02:58 +02:00
Zhang Yi
73733c2fdb ext4: don't write back data before punch hole in nojournal mode
[ Upstream commit 43d0105e2c ]

There is no need to write back all data before punching a hole in
non-journaled mode since it will be dropped soon after removing space.
Therefore, the call to filemap_write_and_wait_range() can be eliminated.
Besides, similar to ext4_zero_range(), we must address the case of
partially punched folios when block size < page size. It is essential to
remove writable userspace mappings to ensure that the folio can be
faulted again during subsequent mmap write access.

In journaled mode, we need to write dirty pages out before discarding
page cache in case of crash before committing the freeing data
transaction, which could expose old, stale data, even if synchronization
has been performed.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20241220011637.1157197-4-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-29 11:02:58 +02:00
Baokun Li
785ac69911 ext4: do not convert the unwritten extents if data writeback fails
[ Upstream commit e856f93e0f ]

When dioread_nolock is turned on (the default), it will convert unwritten
extents to written at ext4_end_io_end(), even if the data writeback fails.

It leads to the possibility that stale data may be exposed when the
physical block corresponding to the file data is read-only (i.e., writes
return -EIO, but reads are normal).

Therefore a new ext4_io_end->flags EXT4_IO_END_FAILED is added, which
indicates that some bio write-back failed in the current ext4_io_end.
When this flag is set, the unwritten to written conversion is no longer
performed. Users can read the data normally until the caches are dropped,
after that, the failed extents can only be read to all 0.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250122110533.4116662-3-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-29 11:02:19 +02:00