Hello,
syzbot found the following issue on:
HEAD commit: 4ef8451b Merge tag 'perf-tools-for-v5.10-2020-11-03' of gi..
git tree: upstream
console output:
https://syzkaller.appspot.com/x/log.txt?x=122bf932500000
kernel config:
https://syzkaller.appspot.com/x/.config?x=76dfc991796328d4
dashboard link:
https://syzkaller.appspot.com/bug?extid=19480160ef25c9ffa29d
compiler: clang version 12.0.0 (
https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [
linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]
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+194801...@syzkaller.appspotmail.com
==================================================================
BUG: KCSAN: data-race in do_epoll_ctl / do_epoll_wait
write to 0xffff88810ca06a18 of 8 bytes by task 8438 on cpu 1:
__list_add include/linux/list.h:70 [inline]
list_add_tail include/linux/list.h:100 [inline]
ep_insert fs/eventpoll.c:1570 [inline]
do_epoll_ctl+0x1ab2/0x1c10 fs/eventpoll.c:2228
__do_sys_epoll_ctl fs/eventpoll.c:2281 [inline]
__se_sys_epoll_ctl fs/eventpoll.c:2272 [inline]
__x64_sys_epoll_ctl+0xb3/0xe0 fs/eventpoll.c:2272
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
read to 0xffff88810ca06a18 of 8 bytes by task 8436 on cpu 0:
list_empty_careful include/linux/list.h:319 [inline]
ep_events_available fs/eventpoll.c:377 [inline]
ep_poll fs/eventpoll.c:1856 [inline]
do_epoll_wait+0x38e/0x810 fs/eventpoll.c:2323
__do_sys_epoll_pwait fs/eventpoll.c:2354 [inline]
__se_sys_epoll_pwait fs/eventpoll.c:2340 [inline]
__x64_sys_epoll_pwait+0x92/0x150 fs/eventpoll.c:2340
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: 8436 Comm: syz-fuzzer Not tainted 5.10.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 8436 Comm: syz-fuzzer Not tainted 5.10.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x116/0x15d lib/dump_stack.c:118
panic+0x1e7/0x5fa kernel/panic.c:231
kcsan_report+0x67b/0x680 kernel/kcsan/report.c:634
kcsan_setup_watchpoint+0x46a/0x4d0 kernel/kcsan/core.c:568
list_empty_careful include/linux/list.h:319 [inline]
ep_events_available fs/eventpoll.c:377 [inline]
ep_poll fs/eventpoll.c:1856 [inline]
do_epoll_wait+0x38e/0x810 fs/eventpoll.c:2323
__do_sys_epoll_pwait fs/eventpoll.c:2354 [inline]
__se_sys_epoll_pwait fs/eventpoll.c:2340 [inline]
__x64_sys_epoll_pwait+0x92/0x150 fs/eventpoll.c:2340
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x469240
Code: 0f 05 89 44 24 20 c3 cc cc cc 8b 7c 24 08 48 8b 74 24 10 8b 54 24 18 44 8b 54 24 1c 49 c7 c0 00 00 00 00 b8 19 01 00 00 0f 05 <89> 44 24 20 c3 cc cc cc cc cc cc cc cc cc cc cc 8b 7c 24 08 48 c7
RSP: 002b:000000c0000497f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000119
RAX: ffffffffffffffda RBX: 0000000000000bb5 RCX: 0000000000469240
RDX: 0000000000000080 RSI: 000000c000049840 RDI: 0000000000000003
RBP: 000000c000049e40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000bb5 R11: 0000000000000246 R12: 0000000000000003
R13: 000000c000000f00 R14: 000080c02eafa000 R15: 000080c02eb19fff
Kernel Offset: disabled
Rebooting in 86400 seconds..
---
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