syzbot


KCSAN: data-race in do_sendfile / ksys_write (16)

Status: moderation: reported on 2024/04/23 12:59
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+4a5812884a6bf667caf2@syzkaller.appspotmail.com
First crash: 10d, last: 10d
Similar bugs (15)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in do_sendfile / ksys_write (5) fs 1 1200d 1200d 0/26 auto-closed as invalid on 2021/02/23 08:15
upstream KCSAN: data-race in do_sendfile / ksys_write (7) fs 3 831d 855d 0/26 auto-closed as invalid on 2022/02/27 04:59
upstream KCSAN: data-race in do_sendfile / ksys_write (8) fs 1 791d 791d 0/26 auto-closed as invalid on 2022/04/08 18:00
upstream KCSAN: data-race in do_sendfile / ksys_write (12) fs 2 320d 333d 0/26 auto-obsoleted due to no activity on 2023/07/23 08:25
upstream KCSAN: data-race in do_sendfile / ksys_write (15) fs 1 70d 70d 0/26 auto-obsoleted due to no activity on 2024/03/29 14:30
upstream KCSAN: data-race in do_sendfile / ksys_write fs 1 1643d 1643d 0/26 closed as invalid on 2019/11/19 13:24
upstream KCSAN: data-race in do_sendfile / ksys_write (14) fs 2 145d 144d 0/26 auto-obsoleted due to no activity on 2024/01/14 07:58
upstream KCSAN: data-race in do_sendfile / ksys_write (13) fs 5 213d 270d 0/26 auto-obsoleted due to no activity on 2023/11/07 08:57
upstream KCSAN: data-race in do_sendfile / ksys_write (2) fs 2 1526d 1589d 0/26 auto-closed as invalid on 2020/05/08 04:57
upstream KCSAN: data-race in do_sendfile / ksys_write (6) fs 1 1132d 1132d 0/26 auto-closed as invalid on 2021/05/17 10:56
upstream KCSAN: data-race in do_sendfile / ksys_write (4) fs 1 1236d 1236d 0/26 auto-closed as invalid on 2021/01/18 19:47
upstream KCSAN: data-race in do_sendfile / ksys_write (10) fs 1 650d 650d 0/26 auto-closed as invalid on 2022/08/27 13:39
upstream KCSAN: data-race in do_sendfile / ksys_write (3) fs 1 1309d 1309d 0/26 auto-closed as invalid on 2020/11/06 02:13
upstream KCSAN: data-race in do_sendfile / ksys_write (9) fs 2 732d 735d 0/26 auto-closed as invalid on 2022/06/06 18:20
upstream KCSAN: data-race in do_sendfile / ksys_write (11) fs 1 583d 583d 0/26 auto-obsoleted due to no activity on 2022/11/02 18:18

Sample crash report:
==================================================================
BUG: KCSAN: data-race in do_sendfile / ksys_write

write to 0xffff888104341740 of 8 bytes by task 23264 on cpu 0:
 do_sendfile+0x787/0x970
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
 x64_sys_call+0x2c67/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff888104341740 of 8 bytes by task 23263 on cpu 1:
 ksys_write+0x11e/0x1b0 fs/read_write.c:645
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:652
 x64_sys_call+0x27b7/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0x0000000000260000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23263 Comm: syz-executor.0 Tainted: G        W          6.9.0-rc5-syzkaller-00031-g71b1543c83d6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/23 12:59 upstream 71b1543c83d6 21339d7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in do_sendfile / ksys_write
* Struck through repros no longer work on HEAD.