syzbot


KCSAN: data-race in copy_process / ksys_unshare (2)

Status: auto-closed as invalid on 2022/03/17 05:22
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 331d, last: 291d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in copy_process / ksys_unshare 1 417d 417d 0/24 auto-closed as invalid on 2021/11/11 12:42

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

write to 0xffff8881008529c0 of 4 bytes by task 16514 on cpu 0:
 copy_fs kernel/fork.c:1523 [inline]
 copy_process+0xef8/0x2f30 kernel/fork.c:2155
 kernel_clone+0x15c/0x6a0 kernel/fork.c:2555
 __do_sys_clone kernel/fork.c:2672 [inline]
 __se_sys_clone kernel/fork.c:2656 [inline]
 __x64_sys_clone+0xc6/0xf0 kernel/fork.c:2656
 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 0xffff8881008529c0 of 4 bytes by task 16520 on cpu 1:
 unshare_fs kernel/fork.c:2961 [inline]
 ksys_unshare+0x237/0x6f0 kernel/fork.c:3039
 __do_sys_unshare kernel/fork.c:3119 [inline]
 __se_sys_unshare kernel/fork.c:3117 [inline]
 __x64_sys_unshare+0x1b/0x20 kernel/fork.c:3117
 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: 0x00000005 -> 0x00000006

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16520 Comm: syz-executor.3 Not tainted 5.17.0-rc3-syzkaller-00043-gf4bc5bbb5fef-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/02/10 05:21 upstream f4bc5bbb5fef 0b33604d .config log report info KCSAN: data-race in copy_process / ksys_unshare
ci2-upstream-kcsan-gce 2022/01/18 18:00 upstream e3a8b6a1e70c 731a2d23 .config log report info KCSAN: data-race in copy_process / ksys_unshare
ci2-upstream-kcsan-gce 2021/12/31 20:43 upstream 4f3d93c6eaff 36bd2e48 .config log report info KCSAN: data-race in copy_process / ksys_unshare
* Struck through repros no longer work on HEAD.