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KCSAN: data-race in do_task_stat / handle_mm_fault

Status: auto-closed as invalid on 2020/10/20 18:42
Subsystems: fs
[Documentation on labels]
First crash: 1325d, last: 1311d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in do_task_stat / handle_mm_fault (2) fs 4 1216d 1228d 0/26 auto-closed as invalid on 2021/01/24 01:57
upstream KCSAN: data-race in do_task_stat / handle_mm_fault (4) fs 1 1068d 1068d 0/26 auto-closed as invalid on 2021/06/20 04:11
upstream KCSAN: data-race in do_task_stat / handle_mm_fault (3) fs 1 1170d 1170d 0/26 auto-closed as invalid on 2021/03/10 04:55
upstream KCSAN: data-race in do_task_stat / handle_mm_fault (5) fs 3 947d 975d 0/26 auto-closed as invalid on 2021/10/19 23:13

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

write to 0xffff8880ae98e610 of 8 bytes by task 22576 on cpu 1:
 mm_account_fault mm/memory.c:4394 [inline]
 handle_mm_fault+0x11f5/0x1af0 mm/memory.c:4458
 do_user_addr_fault+0x380/0x770 arch/x86/mm/fault.c:1372
 handle_page_fault arch/x86/mm/fault.c:1429 [inline]
 exc_page_fault+0xb8/0x330 arch/x86/mm/fault.c:1482
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:538

read to 0xffff8880ae98e610 of 8 bytes by task 1 on cpu 0:
 do_task_stat+0x5ed/0x1020 fs/proc/array.c:504
 proc_tgid_stat+0x2f/0x40 fs/proc/array.c:633
 proc_single_show+0x84/0x100 fs/proc/base.c:775
 seq_read+0x2ee/0x900 fs/seq_file.c:208
 vfs_read+0x16d/0x5e0 fs/read_write.c:479
 ksys_read+0xce/0x180 fs/read_write.c:607
 __do_sys_read fs/read_write.c:617 [inline]
 __se_sys_read fs/read_write.c:615 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:615
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1 Comm: systemd Not tainted 5.9.0-rc5-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
2020/09/15 18:37 upstream fc4f28bb3daf 9e681632 .config console log report info ci2-upstream-kcsan-gce
2020/09/07 17:35 upstream f4d51dffc6c0 abf9ba4f .config console log report ci2-upstream-kcsan-gce
2020/09/02 00:05 upstream b765a32a2e91 abf9ba4f .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.