[moderation] [keyrings?] [lsm?] KCSAN: data-race in key_task_permission / keyctl_chown_key (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: cd2286fc5775 Merge tag 'xfs-6.8-fixes-1' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=178924bbe80000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1bd33f45956bbc2
dashboard link: https://syzkaller.appspot.com/bug?extid=e2d82e1d35c69335de7f
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [dhow...@redhat.com jar...@kernel.org jmo...@namei.org keyr...@vger.kernel.org linux-...@vger.kernel.org linux-secu...@vger.kernel.org pa...@paul-moore.com se...@hallyn.com]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8d1d5b187557/disk-cd2286fc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b8f7a5eaec2e/vmlinux-cd2286fc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5e98a9942012/bzImage-cd2286fc.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e2d82e...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in key_task_permission / keyctl_chown_key

write to 0xffff888120d4916c of 4 bytes by task 13814 on cpu 0:
keyctl_chown_key+0x27c/0x5b0 security/keys/keyctl.c:1045
__do_sys_keyctl security/keys/keyctl.c:1920 [inline]
__se_sys_keyctl+0x112/0xba0 security/keys/keyctl.c:1873
__x64_sys_keyctl+0x67/0x80 security/keys/keyctl.c:1873
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888120d4916c of 4 bytes by task 13813 on cpu 1:
key_task_permission+0x165/0x2b0 security/keys/permission.c:61
lookup_user_key+0x9e9/0xde0 security/keys/process_keys.c:803
keyctl_chown_key+0x112/0x5b0 security/keys/keyctl.c:970
__do_sys_keyctl security/keys/keyctl.c:1920 [inline]
__se_sys_keyctl+0x112/0xba0 security/keys/keyctl.c:1873
__x64_sys_keyctl+0x67/0x80 security/keys/keyctl.c:1873
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00000000 -> 0x239cceba

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13813 Comm: syz-executor.2 Not tainted 6.8.0-rc1-syzkaller-00331-gcd2286fc5775 #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.