syzbot


KCSAN: data-race in do_sendfile / generic_file_llseek_size

Status: auto-closed as invalid on 2022/02/18 10:51
Subsystems: fs
[Documentation on labels]
First crash: 847d, last: 847d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in do_sendfile / generic_file_llseek_size (2) ext4 1 321d 321d 0/26 auto-obsoleted due to no activity on 2023/07/29 04:16
upstream KCSAN: data-race in do_sendfile / generic_file_llseek_size (3) ext4 1 160d 150d 0/26 auto-obsoleted due to no activity on 2024/01/09 18:17

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

write to 0xffff8881043d9468 of 8 bytes by task 2253 on cpu 0:
 vfs_setpos fs/read_write.c:62 [inline]
 generic_file_llseek_size+0x184/0x270 fs/read_write.c:130
 vfs_llseek fs/read_write.c:300 [inline]
 ksys_lseek fs/read_write.c:313 [inline]
 __do_sys_lseek fs/read_write.c:324 [inline]
 __se_sys_lseek fs/read_write.c:322 [inline]
 __x64_sys_lseek+0xf0/0x150 fs/read_write.c:322
 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 0xffff8881043d9468 of 8 bytes by task 2256 on cpu 1:
 do_sendfile+0x129/0xc40 fs/read_write.c:1193
 __do_sys_sendfile64 fs/read_write.c:1310 [inline]
 __se_sys_sendfile64 fs/read_write.c:1296 [inline]
 __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296
 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: 0x0000000000000000 -> 0x0000000000000007

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2256 Comm: syz-executor.0 Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/01/14 10:50 upstream fb3b0673b7d5 b8d780ab .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in do_sendfile / generic_file_llseek_size
* Struck through repros no longer work on HEAD.