[moderation] [fs?] [mm?] KCSAN: data-race in bprm_execve / copy_fs (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e9d22f7a6655 Merge tag 'linux_kselftest-fixes-6.10-rc7' of..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=143a8635980000
kernel config: https://syzkaller.appspot.com/x/.config?x=5b9537cd00be479e
dashboard link: https://syzkaller.appspot.com/bug?extid=d67f2f707d5947d70985
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [bra...@kernel.org ebie...@xmission.com ja...@suse.cz ke...@kernel.org linux-...@vger.kernel.org linux-...@vger.kernel.org linu...@kvack.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/5e3912de3686/disk-e9d22f7a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/06c6ed6b8ced/vmlinux-e9d22f7a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d8d5fa9f2eff/bzImage-e9d22f7a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d67f2f...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in bprm_execve / copy_fs

write to 0xffff888112b93e10 of 4 bytes by task 11199 on cpu 0:
bprm_execve+0x971/0xc60 fs/exec.c:1916
do_execveat_common+0x768/0x7d0 fs/exec.c:1998
do_execveat fs/exec.c:2083 [inline]
__do_sys_execveat fs/exec.c:2157 [inline]
__se_sys_execveat fs/exec.c:2151 [inline]
__x64_sys_execveat+0x75/0x90 fs/exec.c:2151
x64_sys_call+0x8b2/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:323
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 0xffff888112b93e10 of 4 bytes by task 11197 on cpu 1:
copy_fs+0x95/0xf0 kernel/fork.c:1755
copy_process+0xe6c/0x1f90 kernel/fork.c:2381
kernel_clone+0x16a/0x570 kernel/fork.c:2797
__do_sys_clone3 kernel/fork.c:3098 [inline]
__se_sys_clone3+0x1b5/0x1f0 kernel/fork.c:3082
__x64_sys_clone3+0x31/0x40 kernel/fork.c:3082
x64_sys_call+0x28df/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:436
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: 0x00000001 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 11197 Comm: syz.3.1893 Not tainted 6.10.0-rc6-syzkaller-00061-ge9d22f7a6655 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup