syzbot


KCSAN: data-race in __unmap_and_move / delete_from_page_cache_batch

Status: auto-closed as invalid on 2020/12/21 11:51
Reported-by: syzbot+0824a71495e6ee548878@syzkaller.appspotmail.com
First crash: 654d, last: 639d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __unmap_and_move / delete_from_page_cache_batch (2) 1 485d 485d 0/23 auto-closed as invalid on 2021/05/17 09:41

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

write to 0xffffea00043bf358 of 8 bytes by task 17945 on cpu 1:
 page_cache_delete_batch mm/filemap.c:327 [inline]
 delete_from_page_cache_batch+0x36b/0x800 mm/filemap.c:358
 truncate_inode_pages_range+0x482/0xf20 mm/truncate.c:366
 truncate_inode_pages mm/truncate.c:476 [inline]
 truncate_pagecache+0x4f/0x70 mm/truncate.c:839
 ext4_setattr+0xaf9/0xf60 fs/ext4/inode.c:5486
 notify_change+0x7b3/0xa50 fs/attr.c:336
 do_truncate+0xe0/0x120 fs/open.c:64
 handle_truncate fs/namei.c:2910 [inline]
 do_open fs/namei.c:3256 [inline]
 path_openat+0x1a37/0x20a0 fs/namei.c:3369
 do_filp_open+0xbd/0x1d0 fs/namei.c:3396
 do_sys_openat2+0xa3/0x240 fs/open.c:1168
 do_sys_open fs/open.c:1184 [inline]
 __do_sys_openat fs/open.c:1200 [inline]
 __se_sys_openat fs/open.c:1195 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1195
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffffea00043bf358 of 8 bytes by task 17940 on cpu 0:
 __PageMovable include/linux/page-flags.h:490 [inline]
 __unmap_and_move+0x42/0x690 mm/migrate.c:1025
 unmap_and_move+0x130/0x860 mm/migrate.c:1197
 migrate_pages+0x24b/0xb30 mm/migrate.c:1453
 do_mbind mm/mempolicy.c:1351 [inline]
 kernel_mbind+0xe7b/0xff0 mm/mempolicy.c:1472
 __do_sys_mbind mm/mempolicy.c:1479 [inline]
 __se_sys_mbind mm/mempolicy.c:1475 [inline]
 __x64_sys_mbind+0x74/0x80 mm/mempolicy.c:1475
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17940 Comm: syz-executor.2 Not tainted 5.10.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2020/11/08 01:27 upstream 4429f14aeea9 cba33199 .config log report info
ci2-upstream-kcsan-gce 2020/10/24 11:24 upstream f11901ed723d 2bb6666c .config log report info