syzbot


KCSAN: data-race in __dput_to_list / d_walk (2)

Status: auto-closed as invalid on 2022/06/30 17:55
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 184d, last: 184d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __dput_to_list / d_walk 1 232d 232d 0/24 auto-closed as invalid on 2022/05/13 10:59

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

read-write to 0xffff888127d8c840 of 4 bytes by task 6829 on cpu 1:
 d_shrink_add fs/dcache.c:456 [inline]
 __dput_to_list+0x1eb/0x240 fs/dcache.c:928
 shrink_dentry_list+0x19c/0x380 fs/dcache.c:1200
 shrink_dcache_parent+0x3d/0x190
 d_invalidate+0x70/0x1b0 fs/dcache.c:1737
 proc_invalidate_siblings_dcache+0x1e3/0x2d0 fs/proc/inode.c:150
 proc_flush_pid+0x16/0x20 fs/proc/base.c:3345
 release_task+0xbc7/0xcd0 kernel/exit.c:226
 exit_notify kernel/exit.c:708 [inline]
 do_exit+0xf66/0x1720 kernel/exit.c:815
 do_group_exit+0xa5/0x160 kernel/exit.c:925
 get_signal+0xf54/0x1020 kernel/signal.c:2875
 arch_do_signal_or_restart+0x87/0x2d0 arch/x86/kernel/signal.c:869
 exit_to_user_mode_loop+0x78/0x130 kernel/entry/common.c:166
 exit_to_user_mode_prepare kernel/entry/common.c:201 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x6a/0x90 kernel/entry/common.c:294
 do_syscall_64+0x37/0x70 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

read to 0xffff888127d8c840 of 4 bytes by task 1838 on cpu 0:
 d_walk+0x237/0x4e0 fs/dcache.c:1431
 shrink_dcache_parent+0x6e/0x190 fs/dcache.c:1625
 d_invalidate+0x70/0x1b0 fs/dcache.c:1737
 proc_invalidate_siblings_dcache+0x1e3/0x2d0 fs/proc/inode.c:150
 proc_flush_pid+0x16/0x20 fs/proc/base.c:3345
 release_task+0xa9e/0xcd0 kernel/exit.c:226
 wait_task_zombie kernel/exit.c:1111 [inline]
 wait_consider_task+0xfad/0x1750 kernel/exit.c:1338
 do_wait_thread kernel/exit.c:1401 [inline]
 do_wait+0x182/0x670 kernel/exit.c:1518
 kernel_wait4+0x14b/0x1b0 kernel/exit.c:1681
 __do_sys_wait4 kernel/exit.c:1709 [inline]
 __se_sys_wait4 kernel/exit.c:1705 [inline]
 __x64_sys_wait4+0x90/0x120 kernel/exit.c:1705
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

value changed: 0x0020000c -> 0x0028040c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1838 Comm: syz-executor.5 Not tainted 5.18.0-syzkaller-07496-gd7227785e384-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/05/26 17:46 upstream d7227785e384 3037caa9 .config log report info KCSAN: data-race in __dput_to_list / d_walk
* Struck through repros no longer work on HEAD.