[moderation] [selinux?] KCSAN: data-race in avc_policy_seqno / avc_ss_reset (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 8f7c8b88bda4 Merge tag 'sched_ext-for-6.13' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12bec75f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=a4239a0e02e161ec
dashboard link: https://syzkaller.appspot.com/bug?extid=af27e50f664a2a12bcc2
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [linux-...@vger.kernel.org omos...@redhat.com pa...@paul-moore.com sel...@vger.kernel.org stephen.sm...@gmail.com]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/aa6454497bbf/disk-8f7c8b88.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/dd054d382c7b/vmlinux-8f7c8b88.xz
kernel image: https://storage.googleapis.com/syzbot-assets/864b540a4402/bzImage-8f7c8b88.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+af27e5...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in avc_policy_seqno / avc_ss_reset

write to 0xffffffff88bffa48 of 4 bytes by task 7810 on cpu 0:
avc_latest_notif_update security/selinux/avc.c:576 [inline]
avc_ss_reset+0x218/0x250 security/selinux/avc.c:965
selinux_notify_policy_change security/selinux/ss/services.c:2182 [inline]
security_set_bools+0x30b/0x350 security/selinux/ss/services.c:3101
sel_commit_bools_write+0x1de/0x260 security/selinux/selinuxfs.c:1332
do_loop_readv_writev fs/read_write.c:843 [inline]
vfs_writev+0x3fb/0x880 fs/read_write.c:1052
do_writev+0xf4/0x220 fs/read_write.c:1096
__do_sys_writev fs/read_write.c:1164 [inline]
__se_sys_writev fs/read_write.c:1161 [inline]
__x64_sys_writev+0x45/0x50 fs/read_write.c:1161
x64_sys_call+0x1fab/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:21
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

read to 0xffffffff88bffa48 of 4 bytes by task 3016 on cpu 1:
avc_policy_seqno+0x15/0x20 security/selinux/avc.c:1200
selinux_file_permission+0x216/0x360 security/selinux/hooks.c:3638
security_file_permission+0x3d/0x80 security/security.c:2840
iterate_dir+0x5b/0x310 fs/readdir.c:93
__do_sys_getdents64 fs/readdir.c:403 [inline]
__se_sys_getdents64+0x87/0x1a0 fs/readdir.c:389
__x64_sys_getdents64+0x43/0x50 fs/readdir.c:389
x64_sys_call+0x2d24/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:218
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: 0x00000143 -> 0x00000144

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3016 Comm: udevd Not tainted 6.12.0-syzkaller-01892-g8f7c8b88bda4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
==================================================================


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[syzbot]

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