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KCSAN: data-race in ksm_scan_thread / run_store

Status: auto-closed as invalid on 2021/03/02 05:08
Subsystems: mm
[Documentation on labels]
First crash: 1185d, last: 1185d

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

write to 0xffffffff88318a28 of 8 bytes by task 23124 on cpu 0:
 run_store+0x19a/0x2d0 mm/ksm.c:2908
 kobj_attr_store+0x40/0x60 lib/kobject.c:856
 sysfs_kf_write+0xa6/0xc0 fs/sysfs/file.c:139
 kernfs_fop_write_iter+0x1d3/0x2c0 fs/kernfs/file.c:296
 call_write_iter include/linux/fs.h:1901 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x6d4/0x7c0 fs/read_write.c:605
 ksys_write+0xce/0x180 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:667
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffffffff88318a28 of 8 bytes by task 1658 on cpu 1:
 ksmd_should_run mm/ksm.c:2405 [inline]
 ksm_scan_thread+0x1e0/0x5f0 mm/ksm.c:2424
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1658 Comm: ksmd Not tainted 5.11.0-rc5-syzkaller #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
2021/01/26 05:03 upstream f8ad8187c3b5 52e37319 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in ksm_scan_thread / run_store
* Struck through repros no longer work on HEAD.