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KCSAN: data-race in do_sendfile / do_sendfile (8)

Status: moderation: reported on 2024/06/27 21:23
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+b53ccd1d8d8f06f6c8b8@syzkaller.appspotmail.com
First crash: 2d15h, last: 2d15h
▶ ▼ Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in do_sendfile / do_sendfile (3) fs 1 540d 540d 0/27 auto-obsoleted due to no activity on 2023/03/17 22:50
upstream KCSAN: data-race in do_sendfile / do_sendfile (4) fs 4 429d 452d 0/27 auto-obsoleted due to no activity on 2023/06/02 10:13
upstream KCSAN: data-race in do_sendfile / do_sendfile fs 2 863d 878d 0/27 auto-closed as invalid on 2022/03/24 16:27
upstream KCSAN: data-race in do_sendfile / do_sendfile (7) fs 5 153d 202d 0/27 auto-obsoleted due to no activity on 2024/03/03 18:17
upstream KCSAN: data-race in do_sendfile / do_sendfile (6) fs 1 299d 299d 0/27 auto-obsoleted due to no activity on 2023/10/10 12:26
upstream KCSAN: data-race in do_sendfile / do_sendfile (5) fs 3 339d 361d 0/27 auto-obsoleted due to no activity on 2023/08/30 17:21
upstream KCSAN: data-race in do_sendfile / do_sendfile (2) fs 1 679d 679d 0/27 auto-closed as invalid on 2022/09/24 23:59

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

write to 0xffff888112770d40 of 8 bytes by task 25265 on cpu 0:
 do_sendfile+0x781/0x960
 __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+0x2c9f/0x2d70 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 0xffff888112770d40 of 8 bytes by task 25268 on cpu 1:
 do_sendfile+0x753/0x960 fs/read_write.c:1309
 __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+0x2c9f/0x2d70 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 -> 0x00000000003b0000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25268 Comm: syz.2.6900 Not tainted 6.10.0-rc5-syzkaller-00155-g66e55ff12e73 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/27 21:22 upstream 66e55ff12e73 6ef39602 .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.