[moderation] [fs?] KCSAN: data-race in d_delete / do_coredump

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 52b1853b080a Merge tag 'i2c-for-6.7-final' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=101f5a75e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=17e138c8fc533c5e
dashboard link: https://syzkaller.appspot.com/bug?extid=c16bb43851a9c7b82e92
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [bra...@kernel.org linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/32436e2e6cf1/disk-52b1853b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c0a27bdf8e03/vmlinux-52b1853b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f165b88f9643/bzImage-52b1853b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c16bb4...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in d_delete / do_coredump

write to 0xffff888107af5550 of 8 bytes by task 10896 on cpu 1:
__d_drop fs/dcache.c:508 [inline]
d_delete+0xa0/0xf0 fs/dcache.c:2566
d_delete_notify+0x30/0xe0 include/linux/fsnotify.h:260
vfs_unlink+0x305/0x3e0 fs/namei.c:4333
do_unlinkat+0x236/0x4c0 fs/namei.c:4382
do_coredump+0x152f/0x1890 fs/coredump.c:675
get_signal+0xdb5/0x10a0 kernel/signal.c:2890
arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:309
exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168
exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
irqentry_exit_to_user_mode+0x9/0x20 kernel/entry/common.c:309
irqentry_exit+0x12/0x40 kernel/entry/common.c:412
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570

read to 0xffff888107af5550 of 8 bytes by task 10895 on cpu 0:
hlist_bl_unhashed include/linux/list_bl.h:54 [inline]
d_unhashed include/linux/dcache.h:336 [inline]
do_coredump+0x15e5/0x1890 fs/coredump.c:713
get_signal+0xdb5/0x10a0 kernel/signal.c:2890
arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:309
exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168
exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
irqentry_exit_to_user_mode+0x9/0x20 kernel/entry/common.c:309
irqentry_exit+0x12/0x40 kernel/entry/common.c:412
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570

value changed: 0xffff888237a71ea8 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10895 Comm: syz-executor.5 Not tainted 6.7.0-rc8-syzkaller-00177-g52b1853b080a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================


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[syzbot]

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