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KCSAN: data-race in userfaultfd_ioctl / userfaultfd_ioctl (2)

Status: closed as invalid on 2020/01/09 14:13
Subsystems: fs
[Documentation on labels]
First crash: 1614d, last: 1614d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in userfaultfd_ioctl / userfaultfd_ioctl fs 1 1645d 1645d 0/26 closed as invalid on 2019/11/19 13:44
upstream KCSAN: data-race in userfaultfd_ioctl / userfaultfd_ioctl (3) fs 1 1517d 1517d 0/26 auto-closed as invalid on 2020/05/10 10:19
upstream KCSAN: data-race in userfaultfd_ioctl / userfaultfd_ioctl (6) fs 1 1235d 1235d 0/26 auto-closed as invalid on 2021/01/11 23:50
upstream KCSAN: data-race in userfaultfd_ioctl / userfaultfd_ioctl (4) fs 1 1325d 1325d 0/26 auto-closed as invalid on 2020/10/14 02:21
upstream KCSAN: data-race in userfaultfd_ioctl / userfaultfd_ioctl (5) fs 2 1274d 1278d 0/26 auto-closed as invalid on 2020/12/04 12:11

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

write to 0xffff8881221de5f0 of 4 bytes by task 529 on cpu 0:
 userfaultfd_api fs/userfaultfd.c:1850 [inline]
 userfaultfd_ioctl+0x17c2/0x24d0 fs/userfaultfd.c:1869
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x991/0xc60 fs/ioctl.c:696
 ksys_ioctl+0xbd/0xe0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x4c/0x60 fs/ioctl.c:718
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881221de5f0 of 4 bytes by task 561 on cpu 1:
 userfaultfd_ioctl+0x70/0x24d0 fs/userfaultfd.c:1864
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x991/0xc60 fs/ioctl.c:696
 ksys_ioctl+0xbd/0xe0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x4c/0x60 fs/ioctl.c:718
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 561 Comm: syz-executor.5 Not tainted 5.4.0-rc7+ #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
2019/11/24 16:52 https://github.com/google/ktsan.git kcsan 5863cc791e4c 598ca6c8 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.