+Cc Paul data race is in rcu code, presumably not yet discovered by rcutorture? On Mon, 25 Oct 2021 at 12:29, syzbot <syzbot+4dfb96a94317a78f44d9@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: 9c0c4d24ac00 Merge tag 'block-5.15-2021-10-22' of git://gi.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=159c4954b00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6339b6ea86d89fd7 > dashboard link: https://syzkaller.appspot.com/bug?extid=4dfb96a94317a78f44d9 > compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2 > > 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+4dfb96a94317a78f44d9@xxxxxxxxxxxxxxxxxxxxxxxxx > > ================================================================== > BUG: KCSAN: data-race in call_rcu / rcu_gp_fqs_loop > > write to 0xffffffff837342e0 of 8 bytes by task 11 on cpu 1: > rcu_gp_fqs kernel/rcu/tree.c:1910 [inline] > rcu_gp_fqs_loop+0x348/0x470 kernel/rcu/tree.c:1971 > rcu_gp_kthread+0x25/0x1a0 kernel/rcu/tree.c:2130 > kthread+0x262/0x280 kernel/kthread.c:319 > ret_from_fork+0x1f/0x30 > > read to 0xffffffff837342e0 of 8 bytes by task 379 on cpu 0: > __call_rcu_core kernel/rcu/tree.c:2904 [inline] > __call_rcu kernel/rcu/tree.c:3020 [inline] > call_rcu+0x4c0/0x6d0 kernel/rcu/tree.c:3067 > __dentry_kill+0x3ec/0x4e0 fs/dcache.c:596 > dput+0xc6/0x360 fs/dcache.c:888 > do_unlinkat+0x2a8/0x540 fs/namei.c:4172 > __do_sys_unlink fs/namei.c:4217 [inline] > __se_sys_unlink fs/namei.c:4215 [inline] > __x64_sys_unlink+0x2c/0x30 fs/namei.c:4215 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > value changed: 0x0000000000005c0d -> 0x0000000000005c0e > > Reported by Kernel Concurrency Sanitizer on: > CPU: 0 PID: 379 Comm: udevd Tainted: G W 5.15.0-rc6-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > ================================================================== > > > --- > 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 syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
