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KCSAN: data-race in dentry_lru_isolate / step_into

Status: auto-closed as invalid on 2022/06/16 15:50
Subsystems: fs
[Documentation on labels]
First crash: 991d, last: 991d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in dentry_lru_isolate / step_into (2) fs 1 931d 931d 0/28 auto-closed as invalid on 2022/08/15 07:08
upstream KCSAN: data-race in dentry_lru_isolate / step_into (5) kernfs 1 603d 603d 0/28 auto-obsoleted due to no activity on 2023/07/09 13:37
upstream KCSAN: data-race in dentry_lru_isolate / step_into (3) fs 1 832d 832d 0/28 auto-obsoleted due to no activity on 2022/11/22 05:54
upstream KCSAN: data-race in dentry_lru_isolate / step_into (4) fs 5 708d 793d 0/28 auto-obsoleted due to no activity on 2023/04/06 15:13

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

write to 0xffff88813629bcc0 of 4 bytes by task 1833 on cpu 0:
 d_lru_shrink_move fs/dcache.c:480 [inline]
 dentry_lru_isolate+0x134/0x200 fs/dcache.c:1257
 __list_lru_walk_one+0x17b/0x370 mm/list_lru.c:231
 list_lru_walk_one+0x7c/0xa0 mm/list_lru.c:276
 list_lru_shrink_walk include/linux/list_lru.h:194 [inline]
 prune_dcache_sb+0x67/0xa0 fs/dcache.c:1280
 super_cache_scan+0x24e/0x300 fs/super.c:104
 do_shrink_slab+0x2ad/0x600 mm/vmscan.c:774
 shrink_slab_memcg+0x1b9/0x440 mm/vmscan.c:843
 shrink_slab+0x5c/0x1c0 mm/vmscan.c:922
 shrink_node_memcgs+0x27a/0x400 mm/vmscan.c:3100
 shrink_node+0x8c3/0x1110 mm/vmscan.c:3221
 shrink_zones+0x2c1/0x5d0 mm/vmscan.c:3458
 do_try_to_free_pages+0x165/0x720 mm/vmscan.c:3516
 try_to_free_mem_cgroup_pages+0x1cd/0x420 mm/vmscan.c:3830
 reclaim_high+0xcd/0x110 mm/memcontrol.c:2325
 mem_cgroup_handle_over_high+0x75/0x120 mm/memcontrol.c:2509
 resume_user_mode_work include/linux/resume_user_mode.h:58 [inline]
 exit_to_user_mode_loop+0xa5/0x130 kernel/entry/common.c:169
 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+0x44/0xae

read to 0xffff88813629bcc0 of 4 bytes by task 6915 on cpu 1:
 __d_entry_type include/linux/dcache.h:385 [inline]
 d_is_symlink include/linux/dcache.h:415 [inline]
 step_into+0x12b/0x760 fs/namei.c:1854
 walk_component+0x19a/0x280 fs/namei.c:2026
 lookup_last fs/namei.c:2475 [inline]
 path_lookupat+0x11d/0x2b0 fs/namei.c:2499
 filename_lookup+0x130/0x310 fs/namei.c:2528
 user_path_at_empty+0x3e/0x110 fs/namei.c:2851
 user_path_at include/linux/namei.h:57 [inline]
 __do_sys_chdir fs/open.c:490 [inline]
 __se_sys_chdir+0x56/0x150 fs/open.c:484
 __x64_sys_chdir+0x1b/0x20 fs/open.c:484
 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+0x44/0xae

value changed: 0x00280000 -> 0x00008000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 6915 Comm: syz-executor.4 Not tainted 5.18.0-rc6-syzkaller-00009-gfeb9c5e19e91 #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
2022/05/12 15:45 upstream feb9c5e19e91 9ad6612a .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in dentry_lru_isolate / step_into
* Struck through repros no longer work on HEAD.