Hello,
syzbot found the following crash on:
HEAD commit: dcb7fd82 Linux 5.8-rc4
git tree: upstream
console output:
https://syzkaller.appspot.com/x/log.txt?x=1323ae83100000
kernel config:
https://syzkaller.appspot.com/x/.config?x=cb5fa7cd98e489a1
dashboard link:
https://syzkaller.appspot.com/bug?extid=5a0758690f26e1909c08
compiler: clang version 11.0.0 (
https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)
CC: [
linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by:
syzbot+5a0758...@syzkaller.appspotmail.com
==================================================================
BUG: KCSAN: data-race in do_select / pollwake
write to 0xffffc90000dafa70 of 4 bytes by task 8631 on cpu 1:
__pollwake fs/select.c:197 [inline]
pollwake+0xa7/0xf0 fs/select.c:217
__wake_up_common+0xbc/0x130 kernel/sched/wait.c:93
__wake_up_common_lock kernel/sched/wait.c:123 [inline]
__wake_up_sync_key+0x83/0xc0 kernel/sched/wait.c:190
pipe_write+0x9bc/0xbc0 fs/pipe.c:599
call_write_iter include/linux/fs.h:1907 [inline]
new_sync_write fs/read_write.c:484 [inline]
__vfs_write+0x2d8/0x340 fs/read_write.c:497
vfs_write+0x19b/0x350 fs/read_write.c:559
ksys_write+0xce/0x180 fs/read_write.c:612
__do_sys_write fs/read_write.c:624 [inline]
__se_sys_write fs/read_write.c:621 [inline]
__x64_sys_write+0x3e/0x50 fs/read_write.c:621
do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
read to 0xffffc90000dafa70 of 4 bytes by task 8622 on cpu 0:
poll_schedule_timeout fs/select.c:242 [inline]
do_select+0xea6/0xf70 fs/select.c:603
core_sys_select+0x3e3/0x610 fs/select.c:677
kern_select fs/select.c:718 [inline]
__do_sys_select fs/select.c:725 [inline]
__se_sys_select+0x17e/0x1c0 fs/select.c:722
__x64_sys_select+0x63/0x70 fs/select.c:722
do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8622 Comm: sshd Not tainted 5.8.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
---
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