linux

mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-10 20:48:12 +00:00

No description

C 96.8%
Assembly 0.9%
Rust 0.7%
Shell 0.6%
Python 0.5%
Other 0.3%

Find a file

Jeongjun Park 818f916e3a mm: swap: prevent possible data-race in __try_to_reclaim_swap A report [1] was uploaded from syzbot. In the previous commit `862590ac37` ("mm: swap: allow cache reclaim to skip slot cache"), the __try_to_reclaim_swap() function reads offset and folio->entry from folio without folio_lock protection. In the currently reported KCSAN log, it is assumed that the actual data-race will not occur because the calltrace that does WRITE already obtains the folio_lock and then writes. However, the existing __try_to_reclaim_swap() function was already implemented to perform reads under folio_lock protection [1], and there is a risk of a data-race occurring through a function other than the one shown in the KCSAN log. Therefore, I think it is appropriate to change read operations for folio to be performed under folio_lock. [1] ================================================================== BUG: KCSAN: data-race in __delete_from_swap_cache / __try_to_reclaim_swap write to 0xffffea0004c90328 of 8 bytes by task 5186 on cpu 0: __delete_from_swap_cache+0x1f0/0x290 mm/swap_state.c:163 delete_from_swap_cache+0x72/0xe0 mm/swap_state.c:243 folio_free_swap+0x1d8/0x1f0 mm/swapfile.c:1850 free_swap_cache mm/swap_state.c:293 [inline] free_pages_and_swap_cache+0x1fc/0x410 mm/swap_state.c:325 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu+0x2cf/0x440 mm/mmu_gather.c:373 zap_pte_range mm/memory.c:1700 [inline] zap_pmd_range mm/memory.c:1739 [inline] zap_pud_range mm/memory.c:1768 [inline] zap_p4d_range mm/memory.c:1789 [inline] unmap_page_range+0x1f3c/0x22d0 mm/memory.c:1810 unmap_single_vma+0x142/0x1d0 mm/memory.c:1856 unmap_vmas+0x18d/0x2b0 mm/memory.c:1900 exit_mmap+0x18a/0x690 mm/mmap.c:1864 __mmput+0x28/0x1b0 kernel/fork.c:1347 mmput+0x4c/0x60 kernel/fork.c:1369 exit_mm+0xe4/0x190 kernel/exit.c:571 do_exit+0x55e/0x17f0 kernel/exit.c:926 do_group_exit+0x102/0x150 kernel/exit.c:1088 get_signal+0xf2a/0x1070 kernel/signal.c:2917 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffea0004c90328 of 8 bytes by task 5189 on cpu 1: __try_to_reclaim_swap+0x9d/0x510 mm/swapfile.c:198 free_swap_and_cache_nr+0x45d/0x8a0 mm/swapfile.c:1915 zap_pte_range mm/memory.c:1656 [inline] zap_pmd_range mm/memory.c:1739 [inline] zap_pud_range mm/memory.c:1768 [inline] zap_p4d_range mm/memory.c:1789 [inline] unmap_page_range+0xcf8/0x22d0 mm/memory.c:1810 unmap_single_vma+0x142/0x1d0 mm/memory.c:1856 unmap_vmas+0x18d/0x2b0 mm/memory.c:1900 exit_mmap+0x18a/0x690 mm/mmap.c:1864 __mmput+0x28/0x1b0 kernel/fork.c:1347 mmput+0x4c/0x60 kernel/fork.c:1369 exit_mm+0xe4/0x190 kernel/exit.c:571 do_exit+0x55e/0x17f0 kernel/exit.c:926 __do_sys_exit kernel/exit.c:1055 [inline] __se_sys_exit kernel/exit.c:1053 [inline] __x64_sys_exit+0x1f/0x20 kernel/exit.c:1053 x64_sys_call+0x2d46/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:61 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x0000000000000242 -> 0x0000000000000000 Link: https://lkml.kernel.org/r/20241007070623.23340-1-aha310510@gmail.com Reported-by: syzbot+fa43f1b63e3aa6f66329@syzkaller.appspotmail.com Fixes: `862590ac37` ("mm: swap: allow cache reclaim to skip slot cache") Signed-off-by: Jeongjun Park <aha310510@gmail.com> Acked-by: Chris Li <chrisl@kernel.org> Reviewed-by: Kairui Song <kasong@tencent.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>		History 2024-10-17 00:28:11 -07:00
arch	powerpc fixes for 6.12 #4	2024-10-12 17:16:21 -07:00
block	block-6.12-20241004	2024-10-04 10:43:44 -07:00
certs	sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3	2024-09-20 19:52:48 +03:00
crypto	move asm/unaligned.h to linux/unaligned.h	2024-10-02 17:23:23 -04:00
Documentation	Docs/damon/maintainer-profile: update deprecated awslabs GitHub URLs	2024-10-17 00:28:09 -07:00
drivers	USB fixes for 6.12-rc3	2024-10-13 09:21:36 -07:00
fs	fs/proc: fix build with GCC 15 due to -Werror=unterminated-string-initialization	2024-10-17 00:28:07 -07:00
include	mm: huge_memory: add vma_thp_disabled() and thp_disabled_by_hw()	2024-10-17 00:28:10 -07:00
init	cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig	2024-09-26 21:27:27 +02:00
io_uring	io_uring/rw: allow pollable non-blocking attempts for !FMODE_NOWAIT	2024-10-06 20:58:53 -06:00
ipc	struct fd layout change (and conversion to accessor helpers)	2024-09-23 09:35:36 -07:00
kernel	RCU fix for v6.12	2024-10-11 14:42:27 -07:00
lib	maple_tree: check for MA_STATE_BULK on setting wr_rebalance	2024-10-17 00:28:09 -07:00
LICENSES	LICENSES: add 0BSD license text	2024-09-01 20:43:24 -07:00
mm	mm: swap: prevent possible data-race in __try_to_reclaim_swap	2024-10-17 00:28:11 -07:00
net	USB fixes for 6.12-rc3	2024-10-13 09:21:36 -07:00
rust	Driver core fix for 6.12-rc3	2024-10-13 09:10:52 -07:00
samples	[tree-wide] finally take no_llseek out	2024-09-27 08:18:43 -07:00
scripts	kbuild: deb-pkg: Remove blank first line from maint scripts	2024-10-07 02:36:38 +09:00
security	bcachefs: do not use PF_MEMALLOC_NORECLAIM	2024-10-09 12:47:18 -07:00
sound	sound fixes for 6.12-rc2	2024-10-04 11:29:46 -07:00
tools	maple_tree: check for MA_STATE_BULK on setting wr_rebalance	2024-10-17 00:28:09 -07:00
usr	initramfs: shorten cmd_initfs in usr/Makefile	2024-07-16 01:07:52 +09:00
virt	x86:	2024-09-28 09:20:14 -07:00
.clang-format	clang-format: Update with v6.11-rc1's `for_each` macro list	2024-08-02 13:20:31 +02:00
.cocciconfig	scripts: add Linux .cocciconfig for coccinelle	2016-07-22 12:13:39 +02:00
.editorconfig	.editorconfig: remove trim_trailing_whitespace option	2024-06-13 16:47:52 +02:00
.get_maintainer.ignore	Add Jeff Kirsher to .get_maintainer.ignore	2024-03-08 11:36:54 +00:00
.gitattributes	.gitattributes: set diff driver for Rust source code files	2023-05-31 17:48:25 +02:00
.gitignore	Kbuild updates for v6.12	2024-09-24 13:02:06 -07:00
.mailmap	mailmap: add an entry for Andy Chiu	2024-10-17 00:28:08 -07:00
.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	CREDITS: sort alphabetically by name	2024-10-09 12:47:19 -07:00
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	MAINTAINERS: kasan, kcov: add bugzilla links	2024-10-17 00:28:10 -07:00
Makefile	Linux 6.12-rc3	2024-10-13 14:33:32 -07:00
README	README: Fix spelling	2024-03-18 03:36:32 -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 reStructuredText 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.