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KCSAN: data-race in kernel_clone / mm_release (2)

Status: auto-closed as invalid on 2021/12/02 09:15
Subsystems: kernel
[Documentation on labels]
First crash: 923d, last: 904d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in kernel_clone / mm_release kernel 4 992d 1045d 0/26 auto-closed as invalid on 2021/09/04 13:36
upstream KCSAN: data-race in kernel_clone / mm_release (3) kernel 1 777d 777d 0/26 auto-closed as invalid on 2022/04/08 03:37
upstream KCSAN: data-race in kernel_clone / mm_release (4) kernel 1 616d 616d 0/26 auto-closed as invalid on 2022/09/15 13:45

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

write to 0xffff88800af09608 of 8 bytes by task 1180 on cpu 0:
 wait_for_vfork_done kernel/fork.c:1361 [inline]
 kernel_clone+0x35c/0x680 kernel/fork.c:2615
 __do_sys_clone kernel/fork.c:2701 [inline]
 __se_sys_clone kernel/fork.c:2685 [inline]
 __x64_sys_clone+0xc6/0xf0 kernel/fork.c:2685
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88800af09608 of 8 bytes by task 1182 on cpu 1:
 mm_release+0x160/0x210 kernel/fork.c:1412
 exit_mm_release+0x21/0x30 kernel/fork.c:1419
 exit_mm+0x4b/0x3e0 kernel/exit.c:439
 do_exit+0x3ef/0x14a0 kernel/exit.c:812
 do_group_exit+0xa4/0x1a0 kernel/exit.c:922
 __do_sys_exit_group+0xb/0x10 kernel/exit.c:933
 __se_sys_exit_group+0x5/0x10 kernel/exit.c:931
 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:931
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffffc9000240fe18 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1182 Comm: syz-executor.4 Not tainted 5.15.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/10/28 09:06 upstream 1fc596a56b33 be531bb4 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in kernel_clone / mm_release
2021/10/10 17:45 upstream efb52a7d9511 838e7e2c .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in kernel_clone / mm_release
2021/10/08 20:09 upstream 741668ef7832 efe0f24d .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in kernel_clone / mm_release
* Struck through repros no longer work on HEAD.