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KCSAN: data-race in do_task_stat / handle_mm_fault (2)

Status: auto-closed as invalid on 2021/01/24 01:57
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+ba2362d5a0758ad2de50@syzkaller.appspotmail.com
First crash: 1227d, last: 1185d
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 (4) fs 1 1038d 1038d 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 1140d 1140d 0/26 auto-closed as invalid on 2021/03/10 04:55
upstream KCSAN: data-race in do_task_stat / handle_mm_fault fs 3 1280d 1294d 0/26 auto-closed as invalid on 2020/10/20 18:42
upstream KCSAN: data-race in do_task_stat / handle_mm_fault (5) fs 3 916d 945d 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

read-write to 0xffff8881063cd688 of 8 bytes by task 15612 on cpu 0:
 mm_account_fault mm/memory.c:4568 [inline]
 handle_mm_fault+0x15ab/0x17b0 mm/memory.c:4632
 do_user_addr_fault+0x433/0x830 arch/x86/mm/fault.c:1393
 handle_page_fault arch/x86/mm/fault.c:1450 [inline]
 exc_page_fault+0x94/0x2a0 arch/x86/mm/fault.c:1506
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:580

read to 0xffff8881063cd688 of 8 bytes by task 1 on cpu 1:
 do_task_stat+0x5ed/0x10c0 fs/proc/array.c:533
 proc_tgid_stat+0x2f/0x40 fs/proc/array.c:663
 proc_single_show+0x84/0x100 fs/proc/base.c:775
 seq_read_iter+0x2d8/0x8e0 fs/seq_file.c:227
 seq_read+0x221/0x260 fs/seq_file.c:159
 vfs_read+0x154/0x5c0 fs/read_write.c:494
 ksys_read+0xce/0x180 fs/read_write.c:634
 __do_sys_read fs/read_write.c:644 [inline]
 __se_sys_read fs/read_write.c:642 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:642
 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: 1 PID: 1 Comm: systemd Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/12/20 01:56 upstream 467f8165a2b0 04201c06 .config console log report info ci2-upstream-kcsan-gce
2020/12/08 02:35 upstream cd796ed33450 51a9082e .config console log report info ci2-upstream-kcsan-gce
2020/11/27 15:10 upstream 85a2c56cb445 486f93ef .config console log report info ci2-upstream-kcsan-gce
2020/11/08 06:37 upstream 4429f14aeea9 cba33199 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.