linux/fs/ext4
Bhupesh c8e008b604 ext4: ignore xattrs past end
Once inside 'ext4_xattr_inode_dec_ref_all' we should
ignore xattrs entries past the 'end' entry.

This fixes the following KASAN reported issue:

==================================================================
BUG: KASAN: slab-use-after-free in ext4_xattr_inode_dec_ref_all+0xb8c/0xe90
Read of size 4 at addr ffff888012c120c4 by task repro/2065

CPU: 1 UID: 0 PID: 2065 Comm: repro Not tainted 6.13.0-rc2+ #11
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x1fd/0x300
 ? tcp_gro_dev_warn+0x260/0x260
 ? _printk+0xc0/0x100
 ? read_lock_is_recursive+0x10/0x10
 ? irq_work_queue+0x72/0xf0
 ? __virt_addr_valid+0x17b/0x4b0
 print_address_description+0x78/0x390
 print_report+0x107/0x1f0
 ? __virt_addr_valid+0x17b/0x4b0
 ? __virt_addr_valid+0x3ff/0x4b0
 ? __phys_addr+0xb5/0x160
 ? ext4_xattr_inode_dec_ref_all+0xb8c/0xe90
 kasan_report+0xcc/0x100
 ? ext4_xattr_inode_dec_ref_all+0xb8c/0xe90
 ext4_xattr_inode_dec_ref_all+0xb8c/0xe90
 ? ext4_xattr_delete_inode+0xd30/0xd30
 ? __ext4_journal_ensure_credits+0x5f0/0x5f0
 ? __ext4_journal_ensure_credits+0x2b/0x5f0
 ? inode_update_timestamps+0x410/0x410
 ext4_xattr_delete_inode+0xb64/0xd30
 ? ext4_truncate+0xb70/0xdc0
 ? ext4_expand_extra_isize_ea+0x1d20/0x1d20
 ? __ext4_mark_inode_dirty+0x670/0x670
 ? ext4_journal_check_start+0x16f/0x240
 ? ext4_inode_is_fast_symlink+0x2f2/0x3a0
 ext4_evict_inode+0xc8c/0xff0
 ? ext4_inode_is_fast_symlink+0x3a0/0x3a0
 ? do_raw_spin_unlock+0x53/0x8a0
 ? ext4_inode_is_fast_symlink+0x3a0/0x3a0
 evict+0x4ac/0x950
 ? proc_nr_inodes+0x310/0x310
 ? trace_ext4_drop_inode+0xa2/0x220
 ? _raw_spin_unlock+0x1a/0x30
 ? iput+0x4cb/0x7e0
 do_unlinkat+0x495/0x7c0
 ? try_break_deleg+0x120/0x120
 ? 0xffffffff81000000
 ? __check_object_size+0x15a/0x210
 ? strncpy_from_user+0x13e/0x250
 ? getname_flags+0x1dc/0x530
 __x64_sys_unlinkat+0xc8/0xf0
 do_syscall_64+0x65/0x110
 entry_SYSCALL_64_after_hwframe+0x67/0x6f
RIP: 0033:0x434ffd
Code: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 8
RSP: 002b:00007ffc50fa7b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007ffc50fa7e18 RCX: 0000000000434ffd
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000005
RBP: 00007ffc50fa7be0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc50fa7e08 R14: 00000000004bbf30 R15: 0000000000000001
 </TASK>

The buggy address belongs to the object at ffff888012c12000
 which belongs to the cache filp of size 360
The buggy address is located 196 bytes inside of
 freed 360-byte region [ffff888012c12000, ffff888012c12168)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12c12
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x40(head|node=0|zone=0)
page_type: f5(slab)
raw: 0000000000000040 ffff888000ad7640 ffffea0000497a00 dead000000000004
raw: 0000000000000000 0000000000100010 00000001f5000000 0000000000000000
head: 0000000000000040 ffff888000ad7640 ffffea0000497a00 dead000000000004
head: 0000000000000000 0000000000100010 00000001f5000000 0000000000000000
head: 0000000000000001 ffffea00004b0481 ffffffffffffffff 0000000000000000
head: 0000000000000002 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888012c11f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888012c12000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff888012c12080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888012c12100: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
 ffff888012c12180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Reported-by: syzbot+b244bda78289b00204ed@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=b244bda78289b00204ed
Suggested-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Signed-off-by: Bhupesh <bhupesh@igalia.com>
Link: https://patch.msgid.link/20250128082751.124948-2-bhupesh@igalia.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
History 2025-03-16 22:41:17 -04:00
..
.kunitconfig ext4: add .kunitconfig fragment to enable ext4-specific tests 2021-02-11 23:16:30 -05:00
acl.c ext4: convert to ctime accessor functions 2023-07-24 10:29:54 +02:00
acl.h Revert "ext4: apply umask if ACL support is disabled" 2024-05-02 18:25:39 -04:00
balloc.c ext4: fix race in buffer_head read fault injection 2024-11-12 23:54:14 -05:00
bitmap.c ext4: move checksum length calculation of inode bitmap into ext4_inode_bitmap_csum_[verify/set]() functions 2024-09-03 22:12:15 -04:00
block_validity.c ext4: block_validity: Remove unnecessary ‘NULL’ values from new_node 2024-06-27 09:34:00 -04:00
crypto.c ext4: Move CONFIG_UNICODE defguards into the code flow 2024-06-07 17:00:45 +02:00
dir.c ext4: use struct_size() to improve ext4_htree_store_dirent() 2024-11-13 12:56:48 -05:00
ext4.h ext4: remove unused input "inode" in ext4_find_dest_de 2025-03-16 22:41:17 -04:00
ext4_extents.h ext4: fix sparse warnings 2021-08-30 23:36:50 -04:00
ext4_jbd2.c ext4: add ext4_emergency_state() helper function 2025-03-13 10:16:34 -04:00
ext4_jbd2.h ext4: remove unused ext4 journal callback 2025-02-10 07:48:24 -05:00
extents.c ext4: move out common parts into ext4_fallocate() 2025-02-10 07:48:25 -05:00
extents_status.c ext4: Remove a redundant return statement 2025-03-13 09:57:19 -04:00
extents_status.h ext4: don't pass full mapping flags to ext4_es_insert_extent() 2024-11-12 23:54:14 -05:00
fast_commit.c ext4 fast_commit: make use of name_snapshot primitives 2025-01-27 19:24:43 -05:00
fast_commit.h ext4 fast_commit: make use of name_snapshot primitives 2025-01-27 19:24:43 -05:00
file.c ext4: add more ext4_emergency_state() checks around sb_rdonly() 2025-03-13 10:16:34 -04:00
fsmap.c ext4: fix FS_IOC_GETFSMAP handling 2024-11-12 23:52:47 -05:00
fsmap.h ext4: fsmap: fix the block/inode bitmap comment 2021-06-24 09:48:29 -04:00
fsync.c ext4: add ext4_emergency_state() helper function 2025-03-13 10:16:34 -04:00
hash.c ext4: remove redundant checks of s_encoding 2023-08-27 11:27:13 -04:00
ialloc.c ext4: add ext4_emergency_state() helper function 2025-03-13 10:16:34 -04:00
indirect.c ext4: fix race in buffer_head read fault injection 2024-11-12 23:54:14 -05:00
inline.c ext4: remove unused input "inode" in ext4_find_dest_de 2025-03-16 22:41:17 -04:00
inode-test.c ext4: add missing MODULE_DESCRIPTION() 2024-07-05 16:07:24 -04:00
inode.c ext4: add ext4_emergency_state() helper function 2025-03-13 10:16:34 -04:00
ioctl.c ext4: add more ext4_emergency_state() checks around sb_rdonly() 2025-03-13 10:16:34 -04:00
Kconfig ext4: switch to using the crc32c library 2024-12-01 17:23:02 -08:00
Makefile ext4: move ext4 crypto code to its own file crypto.c 2022-05-21 22:24:24 -04:00
mballoc-test.c ext4: fix potential null dereference in ext4 kunit test 2025-03-13 10:01:14 -04:00
mballoc.c ext4: add ext4_emergency_state() helper function 2025-03-13 10:16:34 -04:00
mballoc.h ext4: fix FS_IOC_GETFSMAP handling 2024-11-12 23:52:47 -05:00
migrate.c ext4: fix i_data_sem unlock order in ext4_ind_migrate() 2024-09-03 22:14:17 -04:00
mmp.c ext4: add ext4_emergency_state() helper function 2025-03-13 10:16:34 -04:00
move_extent.c ext4: fix race in buffer_head read fault injection 2024-11-12 23:54:14 -05:00
namei.c ext4: remove unused input "inode" in ext4_find_dest_de 2025-03-16 22:41:17 -04:00
orphan.c ext4: remove trailing newline from ext4_msg() message 2022-12-08 21:49:23 -05:00
page-io.c ext4: add ext4_emergency_state() helper function 2025-03-13 10:16:34 -04:00
readpage.c ext4: reduce stack usage in ext4_mpage_readpages() 2024-08-26 21:47:03 -04:00
resize.c ext4: fix race in buffer_head read fault injection 2024-11-12 23:54:14 -05:00
super.c ext4: show 'shutdown' hint when ext4 is forced to shutdown 2025-03-13 10:16:35 -04:00
symlink.c ext4_get_link(): fix breakage in RCU mode 2024-02-25 02:10:32 -05:00
sysfs.c ext4: add positive int attr pointer to avoid sysfs variables overflow 2024-05-02 23:48:30 -04:00
truncate.h ext4: Convert to use mapping->invalidate_lock 2021-07-13 14:29:00 +02:00
verity.c fs: Convert aops->write_begin to take a folio 2024-08-07 11:33:21 +02:00
xattr.c ext4: ignore xattrs past end 2025-03-16 22:41:17 -04:00
xattr.h ext4: annotate struct ext4_xattr_inode_array with __counted_by() 2024-08-26 23:40:06 -04:00
xattr_hurd.c fs: port xattr to mnt_idmap 2023-01-19 09:24:28 +01:00
xattr_security.c fs: port xattr to mnt_idmap 2023-01-19 09:24:28 +01:00
xattr_trusted.c fs: port xattr to mnt_idmap 2023-01-19 09:24:28 +01:00
xattr_user.c fs: port xattr to mnt_idmap 2023-01-19 09:24:28 +01:00