kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-10-24 19:10:26 +00:00
Code Issues Releases Packages Activity
No description
1,154,209 commits 117 branches 5,803 tags 5.7 GiB
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Miaohe Lin 0c42f7e039 fork: defer linking file vma until vma is fully initialized 
commit 35e351780f upstream.

Thorvald reported a WARNING [1]. And the root cause is below race:

 CPU 1					CPU 2
 fork					hugetlbfs_fallocate
  dup_mmap				 hugetlbfs_punch_hole
   i_mmap_lock_write(mapping);
   vma_interval_tree_insert_after -- Child vma is visible through i_mmap tree.
   i_mmap_unlock_write(mapping);
   hugetlb_dup_vma_private -- Clear vma_lock outside i_mmap_rwsem!
					 i_mmap_lock_write(mapping);
   					 hugetlb_vmdelete_list
					  vma_interval_tree_foreach
					   hugetlb_vma_trylock_write -- Vma_lock is cleared.
   tmp->vm_ops->open -- Alloc new vma_lock outside i_mmap_rwsem!
					   hugetlb_vma_unlock_write -- Vma_lock is assigned!!!
					 i_mmap_unlock_write(mapping);

hugetlb_dup_vma_private() and hugetlb_vm_op_open() are called outside
i_mmap_rwsem lock while vma lock can be used in the same time.  Fix this
by deferring linking file vma until vma is fully initialized.  Those vmas
should be initialized first before they can be used.

Link: https://lkml.kernel.org/r/20240410091441.3539905-1-linmiaohe@huawei.com
Fixes: 8d9bfb2608 ("hugetlb: add vma based lock for pmd sharing")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reported-by: Thorvald Natvig <thorvald@google.com>
Closes: https://lore.kernel.org/linux-mm/20240129161735.6gmjsswx62o4pbja@revolver/T/ [1]
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Tycho Andersen <tandersen@netflix.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2024-05-02 16:29:27 +02:00
arch ARM: dts: microchip: at91-sama7g5ek: Replace regulator-suspend-voltage with the valid property 2024-05-02 16:29:23 +02:00
block block: prevent division by zero in blk_rq_stat_sum() 2024-04-13 13:05:12 +02:00
certs certs: Fix build error when PKCS#11 URI contains semicolon 2023-02-09 11:28:11 +01:00
crypto Revert "crypto: api - Disallow identical driver names" 2024-05-02 16:29:27 +02:00
Documentation net: make SK_MEMORY_PCPU_RESERV tunable 2024-05-02 16:29:24 +02:00
drivers virtio_net: Do not send RSS key if it is not supported 2024-05-02 16:29:27 +02:00
fs cifs: Replace remaining 1-element arrays 2024-05-02 16:29:27 +02:00
include af_unix: Suppress false-positive lockdep splat for spin_lock() in __unix_gc(). 2024-05-02 16:29:27 +02:00
init init/main.c: Fix potential static_command_line memory overflow 2024-04-27 17:07:16 +02:00
io_uring io_uring: Fix io_cqring_wait() not restoring sigmask on get_timespec64() failure 2024-04-27 17:07:04 +02:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel fork: defer linking file vma until vma is fully initialized 2024-05-02 16:29:27 +02:00
lib bootconfig: use memblock_free_late to free xbc memory to buddy 2024-04-27 17:07:17 +02:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm/memory-failure: fix deadlock when hugetlb_optimize_vmemmap is enabled 2024-04-27 17:07:16 +02:00
net af_unix: Suppress false-positive lockdep splat for spin_lock() in __unix_gc(). 2024-05-02 16:29:27 +02:00
rust rust: allocator: Prevent mis-aligned allocation 2023-08-11 12:08:18 +02:00
samples work around gcc bugs with 'asm goto' with outputs 2024-02-23 09:12:28 +01:00
scripts gcc-plugins/stackleak: Avoid .head.text section 2024-04-13 13:05:23 +02:00
security landlock: Warn once if a Landlock action is requested while disabled 2024-04-03 15:19:32 +02:00
sound Revert "ASoC: ti: Convert Pandora ASoC to GPIO descriptors" 2024-04-29 12:32:48 +02:00
tools selftests/ftrace: Limit length in subsystem-enable tests 2024-04-27 17:07:04 +02:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt KVM: Always flush async #PF workqueue when vCPU is being destroyed 2024-04-03 15:19:25 +02:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS ALSA: scarlett2: Rename scarlett_gen2 to scarlett2 2024-04-27 17:07:11 +02:00
Makefile Linux 6.1.89 2024-04-29 12:32:48 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.