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KCSAN: data-race in d_delete / step_into

Status: closed as invalid on 2020/06/18 14:13
Subsystems: fs
[Documentation on labels]
First crash: 1410d, last: 1409d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in d_delete / step_into (6) fs 653 23h18m 112d 0/26 moderation: reported on 2023/12/07 10:03
upstream KCSAN: data-race in d_delete / step_into (5) fs 3 988d 1024d 0/26 auto-closed as invalid on 2021/08/17 20:13
upstream KCSAN: data-race in d_delete / step_into (3) fs 1 1166d 1166d 0/26 auto-closed as invalid on 2021/02/21 16:24
upstream KCSAN: data-race in d_delete / step_into (2) fs 2 1340d 1356d 0/26 auto-closed as invalid on 2020/08/30 20:17
upstream KCSAN: data-race in d_delete / step_into (4) fs 3 1101d 1114d 0/26 auto-closed as invalid on 2021/05/17 11:48

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

write to 0xffff88811ecf0300 of 4 bytes by task 10274 on cpu 0:
 d_delete fs/dcache.c:2450 [inline]
 d_delete+0xbc/0xe0 fs/dcache.c:2440
 vfs_unlink+0x3b5/0x400 fs/namei.c:3823
 do_unlinkat+0x33f/0x550 fs/namei.c:3873
 __do_sys_unlink fs/namei.c:3920 [inline]
 __se_sys_unlink fs/namei.c:3918 [inline]
 __x64_sys_unlink+0x38/0x50 fs/namei.c:3918
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811ecf0300 of 4 bytes by task 5279 on cpu 1:
 d_is_symlink include/linux/dcache.h:419 [inline]
 step_into+0xea/0x1090 fs/namei.c:1680
 walk_component+0xde/0x390 fs/namei.c:1852
 lookup_last fs/namei.c:2295 [inline]
 path_lookupat.isra.0+0x119/0x350 fs/namei.c:2319
 filename_lookup+0x145/0x2c0 fs/namei.c:2352
 user_path_at_empty+0x47/0x60 fs/namei.c:2632
 do_readlinkat+0x89/0x230 fs/stat.c:409
 __do_sys_readlink fs/stat.c:442 [inline]
 __se_sys_readlink fs/stat.c:439 [inline]
 __x64_sys_readlink+0x4c/0x60 fs/stat.c:439
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5279 Comm: systemd-udevd Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/05/19 05:52 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 684d3606 .config console log report ci2-upstream-kcsan-gce
2020/05/18 13:11 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 24d91142 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.