syzbot


KCSAN: data-race in do_sendfile / do_sendfile (10)

Status: moderation: reported on 2024/11/13 18:24
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+be39254b0cdfa55a2579@syzkaller.appspotmail.com
First crash: 4d07h, last: 4d07h
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in do_sendfile / do_sendfile (3) fs 1 681d 681d 0/28 auto-obsoleted due to no activity on 2023/03/17 22:50
upstream KCSAN: data-race in do_sendfile / do_sendfile (4) fs 4 569d 592d 0/28 auto-obsoleted due to no activity on 2023/06/02 10:13
upstream KCSAN: data-race in do_sendfile / do_sendfile fs 2 1004d 1019d 0/28 auto-closed as invalid on 2022/03/24 16:27
upstream KCSAN: data-race in do_sendfile / do_sendfile (9) fs 1 63d 63d 0/28 auto-obsoleted due to no activity on 2024/10/20 07:46
upstream KCSAN: data-race in do_sendfile / do_sendfile (7) fs 5 294d 343d 0/28 auto-obsoleted due to no activity on 2024/03/03 18:17
upstream KCSAN: data-race in do_sendfile / do_sendfile (6) fs 1 439d 439d 0/28 auto-obsoleted due to no activity on 2023/10/10 12:26
upstream KCSAN: data-race in do_sendfile / do_sendfile (5) fs 3 480d 501d 0/28 auto-obsoleted due to no activity on 2023/08/30 17:21
upstream KCSAN: data-race in do_sendfile / do_sendfile (8) fs 2 119d 143d 0/28 auto-obsoleted due to no activity on 2024/08/25 22:44
upstream KCSAN: data-race in do_sendfile / do_sendfile (2) fs 1 820d 820d 0/28 auto-closed as invalid on 2022/09/24 23:59

Sample crash report:
ext4 filesystem being mounted at /141/file0 supports timestamps until 2038-01-19 (0x7fffffff)
==================================================================
BUG: KCSAN: data-race in do_sendfile / do_sendfile

write to 0xffff8881168d51f0 of 8 bytes by task 5956 on cpu 0:
 do_sendfile+0x76e/0x970
 __do_sys_sendfile64 fs/read_write.c:1455 [inline]
 __se_sys_sendfile64 fs/read_write.c:1441 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1441
 x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff8881168d51f0 of 8 bytes by task 5950 on cpu 1:
 do_sendfile+0x76e/0x970
 __do_sys_sendfile64 fs/read_write.c:1455 [inline]
 __se_sys_sendfile64 fs/read_write.c:1441 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1441
 x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0x00000000000002e2

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 5950 Comm: syz.1.717 Not tainted 6.12.0-rc7-syzkaller-00042-gf1b785f4c787 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/13 18:24 upstream f1b785f4c787 bb3f8425 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in do_sendfile / do_sendfile
* Struck through repros no longer work on HEAD.