syzbot


KCSAN: data-race in io_submit_sqes / io_uring_poll

Status: auto-closed as invalid on 2020/10/29 16:22
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 764d, last: 738d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in io_submit_sqes / io_uring_poll (2) 1 637d 637d 0/24 auto-closed as invalid on 2021/02/08 06:39
upstream KCSAN: data-race in io_submit_sqes / io_uring_poll (3) 55 315d 392d 0/24 auto-closed as invalid on 2021/12/27 08:47
upstream KCSAN: data-race in io_submit_sqes / io_uring_poll (4) 123 36d 202d 0/24 auto-obsoleted due to no activity on 2022/10/01 12:19

Sample crash report:
==================================================================
BUG: KCSAN: data-race in io_submit_sqes / io_uring_poll

write to 0xffff88804fe4c050 of 4 bytes by task 31086 on cpu 1:
 io_consume_sqe fs/io_uring.c:6407 [inline]
 io_submit_sqes+0x785/0xfb0 fs/io_uring.c:6508
 __do_sys_io_uring_enter fs/io_uring.c:8349 [inline]
 __se_sys_io_uring_enter+0x1e8/0x790 fs/io_uring.c:8308
 __x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:8308
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88804fe4c050 of 4 bytes by task 31092 on cpu 0:
 io_uring_poll+0x90/0x140 fs/io_uring.c:7936
 vfs_poll include/linux/poll.h:90 [inline]
 do_pollfd fs/select.c:869 [inline]
 do_poll fs/select.c:917 [inline]
 do_sys_poll+0x606/0xbc0 fs/select.c:1011
 __do_sys_ppoll fs/select.c:1111 [inline]
 __se_sys_ppoll+0x169/0x1b0 fs/select.c:1091
 __x64_sys_ppoll+0x63/0x70 fs/select.c:1091
 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: 31092 Comm: syz-executor.2 Not tainted 5.9.0-rc6-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: 31092 Comm: syz-executor.2 Not tainted 5.9.0-rc6-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+0x10f/0x19d lib/dump_stack.c:118
 panic+0x207/0x64a kernel/panic.c:231
 kcsan_report+0x684/0x690 kernel/kcsan/report.c:630
 kcsan_setup_watchpoint+0x41e/0x4a0 kernel/kcsan/core.c:540
 io_uring_poll+0x90/0x140 fs/io_uring.c:7936
 vfs_poll include/linux/poll.h:90 [inline]
 do_pollfd fs/select.c:869 [inline]
 do_poll fs/select.c:917 [inline]
 do_sys_poll+0x606/0xbc0 fs/select.c:1011
 __do_sys_ppoll fs/select.c:1111 [inline]
 __se_sys_ppoll+0x169/0x1b0 fs/select.c:1091
 __x64_sys_ppoll+0x63/0x70 fs/select.c:1091
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e179
Code: 3d b2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 0b b2 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f38a9fe5c78 EFLAGS: 00000246 ORIG_RAX: 000000000000010f
RAX: ffffffffffffffda RBX: 0000000000024bc0 RCX: 000000000045e179
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000020000280
RBP: 000000000118d038 R08: 0000000000000008 R09: 0000000000000000
R10: 0000000020000300 R11: 0000000000000246 R12: 000000000118cff4
R13: 00007ffd24f444cf R14: 00007f38a9fe69c0 R15: 000000000118cff4
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2020/09/24 16:17 upstream c9c9e6a49f89 54289b08 .config log report info
ci2-upstream-kcsan-gce 2020/08/29 16:36 upstream 4d41ead6ead9 d5a3ae1f .config log report
* Struck through repros no longer work on HEAD.