KCSAN: data-race in tomoyo_check_path_acl / tomoyo_merge_path_acl (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e28c0d7c Merge branch 'akpm' (patches from Andrew)
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=133cfd9a500000
kernel config: https://syzkaller.appspot.com/x/.config?x=671e27f23e60a67b
dashboard link: https://syzkaller.appspot.com/bug?extid=bb609466f777542a0aba
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [jmo...@namei.org linux-...@vger.kernel.org linux-secu...@vger.kernel.org penguin...@I-love.SAKURA.ne.jp se...@hallyn.com take...@nttdata.co.jp]

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bb6094...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in tomoyo_check_path_acl / tomoyo_merge_path_acl

write to 0xffff88810c95929a of 2 bytes by task 8435 on cpu 1:
tomoyo_merge_path_acl+0x4c/0x70 security/tomoyo/file.c:372
tomoyo_update_domain+0x337/0x3a0 security/tomoyo/domain.c:131
tomoyo_update_path_acl security/tomoyo/file.c:398 [inline]
tomoyo_write_file+0x210/0x910 security/tomoyo/file.c:1022
tomoyo_write_domain2 security/tomoyo/common.c:1152 [inline]
tomoyo_add_entry security/tomoyo/common.c:2042 [inline]
tomoyo_supervisor+0xaad/0xb20 security/tomoyo/common.c:2103
tomoyo_audit_path_log security/tomoyo/file.c:168 [inline]
tomoyo_path_permission security/tomoyo/file.c:587 [inline]
tomoyo_path_perm+0x261/0x330 security/tomoyo/file.c:838
tomoyo_path_truncate+0x18/0x20 security/tomoyo/tomoyo.c:135
security_path_truncate+0x7f/0xd0 security/security.c:1145
do_sys_ftruncate+0x38d/0x530 fs/open.c:193
__do_sys_ftruncate fs/open.c:205 [inline]
__se_sys_ftruncate fs/open.c:203 [inline]
__x64_sys_ftruncate+0x2f/0x40 fs/open.c:203
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810c95929a of 2 bytes by task 8459 on cpu 0:
tomoyo_check_path_acl+0x1e/0xe0 security/tomoyo/file.c:258
tomoyo_check_acl+0xcc/0x200 security/tomoyo/domain.c:175
tomoyo_execute_permission+0xa1/0x190 security/tomoyo/file.c:615
tomoyo_find_next_domain+0x213/0x10a0 security/tomoyo/domain.c:754
tomoyo_bprm_check_security+0x96/0xd0 security/tomoyo/tomoyo.c:101
security_bprm_check+0x3f/0x90 security/security.c:841
search_binary_handler fs/exec.c:1691 [inline]
exec_binprm+0x143/0x720 fs/exec.c:1744
bprm_execve+0x435/0x610 fs/exec.c:1820
do_execveat_common+0x60c/0x6c0 fs/exec.c:1915
do_execve fs/exec.c:1983 [inline]
__do_sys_execve fs/exec.c:2059 [inline]
__se_sys_execve fs/exec.c:2054 [inline]
__x64_sys_execve+0x56/0x70 fs/exec.c:2054
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8459 Comm: syz-fuzzer Not tainted 5.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


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[syzbot]

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