[moderation] [fs?] KCSAN: data-race in generic_permission / setattr_copy (8)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 77a903cd8e5a MAINTAINERS: powerpc: Update my status
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1003b218580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9ab3e6c069ff12aa
dashboard link: https://syzkaller.appspot.com/bug?extid=7ba4a35d106e16d95bbb
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [amir...@gmail.com ja...@suse.cz linux-...@vger.kernel.org linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c1f988937299/disk-77a903cd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c102e69cfb90/vmlinux-77a903cd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e7f61d7c13ee/bzImage-77a903cd.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7ba4a3...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in generic_permission / setattr_copy

write to 0xffff888101fe4080 of 2 bytes by task 26 on cpu 0:
setattr_copy+0x18c/0x4a0 fs/attr.c:352
shmem_setattr+0x532/0x830 mm/shmem.c:1262
notify_change+0x85c/0x8e0 fs/attr.c:552
handle_remove drivers/base/devtmpfs.c:337 [inline]
handle drivers/base/devtmpfs.c:386 [inline]
devtmpfs_work_loop+0x841/0x8f0 drivers/base/devtmpfs.c:399
devtmpfsd+0x47/0x50 drivers/base/devtmpfs.c:441
kthread+0x1d1/0x210 kernel/kthread.c:389
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffff888101fe4080 of 2 bytes by task 14797 on cpu 1:
acl_permission_check fs/namei.c:383 [inline]
generic_permission+0x29/0x460 fs/namei.c:471
do_inode_permission fs/namei.c:532 [inline]
inode_permission+0x77/0x300 fs/namei.c:592
path_permission include/linux/fs.h:2937 [inline]
inotify_find_inode fs/notify/inotify/inotify_user.c:381 [inline]
__do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:771 [inline]
__se_sys_inotify_add_watch+0x17c/0x790 fs/notify/inotify/inotify_user.c:729
__x64_sys_inotify_add_watch+0x43/0x50 fs/notify/inotify/inotify_user.c:729
x64_sys_call+0x1f6d/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:255
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: 0x61b0 -> 0x6000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 14797 Comm: udevd Not tainted 6.13.0-rc6-syzkaller-00231-g77a903cd8e5a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.