syzbot


KCSAN: data-race in opipe_prep / pipe_write (2)

Status: auto-closed as invalid on 2022/03/11 16:40
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 304d, last: 304d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in opipe_prep / pipe_write 1 471d 471d 0/24 auto-closed as invalid on 2021/09/25 17:57

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

write to 0xffff88814c8597d0 of 4 bytes by task 26450 on cpu 1:
 pipe_write+0x458/0xda0 fs/pipe.c:516
 call_write_iter include/linux/fs.h:2074 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x7f5/0x950 fs/read_write.c:590
 ksys_write+0xd9/0x190 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:652
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88814c8597d0 of 4 bytes by task 26455 on cpu 0:
 opipe_prep+0x26/0x200 fs/splice.c:1407
 splice_pipe_to_pipe fs/splice.c:1454 [inline]
 do_splice+0x30e/0xde0 fs/splice.c:1054
 __do_splice fs/splice.c:1144 [inline]
 __do_sys_splice fs/splice.c:1350 [inline]
 __se_sys_splice+0x2bd/0x3a0 fs/splice.c:1332
 __x64_sys_splice+0x74/0x80 fs/splice.c:1332
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 26455 Comm: syz-executor.4 Not tainted 5.17.0-rc2-syzkaller-00167-gdcb85f85fa6f-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/02/04 16:38 upstream dcb85f85fa6f a3e470b2 .config log report info KCSAN: data-race in opipe_prep / pipe_write
* Struck through repros no longer work on HEAD.