syzbot


KCSAN: data-race in ext4_mpage_readpages / ext4_setattr (2)

Status: auto-closed as invalid on 2021/03/15 11:12
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+1c07301bb00f6574534a@syzkaller.appspotmail.com
First crash: 1358d, last: 1134d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_mpage_readpages / ext4_setattr ext4 3 1477d 1552d 0/26 auto-closed as invalid on 2020/05/12 04:51
upstream KCSAN: data-race in ext4_mpage_readpages / ext4_setattr (4) ext4 5 951d 990d 0/26 auto-closed as invalid on 2021/09/15 01:54
upstream KCSAN: data-race in ext4_mpage_readpages / ext4_setattr (3) ext4 8 1027d 1075d 0/26 auto-closed as invalid on 2021/06/30 12:56

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_mpage_readpages / ext4_setattr

write to 0xffff8881101b8190 of 8 bytes by task 11362 on cpu 0:
 i_size_write include/linux/fs.h:870 [inline]
 ext4_setattr+0xe19/0xf60 fs/ext4/inode.c:5483
 notify_change+0x86d/0xa60 fs/attr.c:336
 do_truncate fs/open.c:64 [inline]
 do_sys_ftruncate+0x42d/0x530 fs/open.c:195
 __do_sys_ftruncate fs/open.c:205 [inline]
 __se_sys_ftruncate fs/open.c:203 [inline]
 __x64_sys_ftruncate+0x2f/0x40 fs/open.c:203
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881101b8190 of 8 bytes by task 11357 on cpu 1:
 ext4_readpage_limit fs/ext4/readpage.c:219 [inline]
 ext4_mpage_readpages+0x4f9/0x15c0 fs/ext4/readpage.c:265
 ext4_readahead+0x99/0xa0 fs/ext4/inode.c:3261
 read_pages+0x9c/0x6e0 mm/readahead.c:130
 page_cache_ra_unbounded+0x46c/0x4c0 mm/readahead.c:238
 ondemand_readahead+0x560/0x780 mm/readahead.c:267
 page_cache_sync_ra+0x18f/0x1a0 mm/readahead.c:577
 page_cache_sync_readahead include/linux/pagemap.h:839 [inline]
 generic_file_buffered_read_get_pages+0x234/0xaf0 mm/filemap.c:2365
 generic_file_buffered_read+0x26e/0x9c0 mm/filemap.c:2485
 generic_file_read_iter+0x82/0x3e0 mm/filemap.c:2637
 ext4_file_read_iter+0x2e0/0x430 fs/ext4/file.c:74
 call_read_iter include/linux/fs.h:1895 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:311
 do_splice_to fs/splice.c:788 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:867
 do_splice_direct+0xf5/0x170 fs/splice.c:976
 do_sendfile+0x5e0/0xcf0 fs/read_write.c:1257
 __do_sys_sendfile64 fs/read_write.c:1318 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304
 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: 1 PID: 11357 Comm: syz-executor.3 Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (15):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/02/08 11:11 upstream 92bf22614b21 2ce644fc .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in ext4_mpage_readpages / ext4_setattr
2021/01/30 18:40 upstream 0e9bcda5d286 fc9fd31e .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in ext4_mpage_readpages / ext4_setattr
2021/01/08 06:55 upstream f5e6c330254a c104d4a3 .config console log report info ci2-upstream-kcsan-gce
2020/12/31 16:34 upstream f6e1ea196492 79264ae3 .config console log report info ci2-upstream-kcsan-gce
2020/12/01 12:24 upstream b65054597872 07bfe8a5 .config console log report info ci2-upstream-kcsan-gce
2020/11/19 21:41 upstream 131ad0b6f529 0767f13f .config console log report info ci2-upstream-kcsan-gce
2020/11/16 11:58 upstream 09162bc32c88 1bf9a662 .config console log report info ci2-upstream-kcsan-gce
2020/10/25 19:22 upstream 986b9eacb259 a1839e81 .config console log report info ci2-upstream-kcsan-gce
2020/09/28 02:58 upstream a1b8638ba132 5dd8aee8 .config console log report info ci2-upstream-kcsan-gce
2020/09/23 22:40 upstream c9c9e6a49f89 54289b08 .config console log report info ci2-upstream-kcsan-gce
2020/09/18 12:58 upstream 10b82d517648 38962c8b .config console log report info ci2-upstream-kcsan-gce
2020/08/25 22:56 upstream abb3438d69fb 344da168 .config console log report ci2-upstream-kcsan-gce
2020/08/04 08:09 upstream e4cbce4d1317 96dd3623 .config console log report ci2-upstream-kcsan-gce
2020/07/08 07:55 upstream dcde237b9b0e 5962a2dc .config console log report ci2-upstream-kcsan-gce
2020/06/29 16:26 upstream 9ebcfadb0610 ce9ef6f2 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.