syzbot


KCSAN: data-race in __mpage_writepage / generic_write_end (2)

Status: auto-closed as invalid on 2020/10/09 21:50
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 946d, last: 881d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __mpage_writepage / generic_write_end 7 963d 993d 0/24 closed as invalid on 2020/06/18 14:13
upstream KCSAN: data-race in __mpage_writepage / generic_write_end (5) 1 271d 271d 0/24 auto-closed as invalid on 2022/06/11 23:17
upstream KCSAN: data-race in __mpage_writepage / generic_write_end (3) 1 791d 787d 0/24 auto-closed as invalid on 2021/01/07 12:23
upstream KCSAN: data-race in __mpage_writepage / generic_write_end (4) 2 328d 362d 0/24 auto-closed as invalid on 2022/04/16 04:47

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __mpage_writepage / generic_write_end

write to 0xffff8880bae0c198 of 8 bytes by task 27486 on cpu 1:
 i_size_write include/linux/fs.h:876 [inline]
 generic_write_end+0x99/0x250 fs/buffer.c:2186
 fat_write_end+0x4a/0x160 fs/fat/inode.c:249
 generic_perform_write+0x23b/0x390 mm/filemap.c:3414
 __generic_file_write_iter+0x154/0x330 mm/filemap.c:3532
 generic_file_write_iter+0x2f3/0x3e0 mm/filemap.c:3564
 call_write_iter include/linux/fs.h:1882 [inline]
 do_iter_readv_writev+0x32e/0x3d0 fs/read_write.c:713
 do_iter_write+0x112/0x4b0 fs/read_write.c:1018
 vfs_iter_write+0x4c/0x70 fs/read_write.c:1059
 iter_file_splice_write+0x41a/0x770 fs/splice.c:750
 do_splice_from fs/splice.c:846 [inline]
 direct_splice_actor+0x95/0x160 fs/splice.c:1016
 splice_direct_to_actor+0x365/0x660 fs/splice.c:971
 do_splice_direct+0xf2/0x170 fs/splice.c:1059
 do_sendfile+0x56a/0xba0 fs/read_write.c:1540
 __do_sys_sendfile64 fs/read_write.c:1601 [inline]
 __se_sys_sendfile64 fs/read_write.c:1587 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1587
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880bae0c198 of 8 bytes by task 27493 on cpu 0:
 i_size_read include/linux/fs.h:854 [inline]
 __mpage_writepage+0x95/0x1070 fs/mpage.c:501
 write_cache_pages+0x4cb/0x840 mm/page-writeback.c:2246
 mpage_writepages+0x6d/0x120 fs/mpage.c:714
 fat_writepages+0x20/0x30 fs/fat/inode.c:205
 do_writepages+0x7b/0x150 mm/page-writeback.c:2352
 __filemap_fdatawrite_range+0x19b/0x1d0 mm/filemap.c:422
 filemap_write_and_wait_range+0x8b/0x2a0 mm/filemap.c:655
 generic_file_read_iter+0x11d/0x3e0 mm/filemap.c:2375
 call_read_iter include/linux/fs.h:1876 [inline]
 generic_file_splice_read+0x22b/0x310 fs/splice.c:312
 do_splice_to fs/splice.c:870 [inline]
 splice_direct_to_actor+0x2a8/0x660 fs/splice.c:950
 do_splice_direct+0xf2/0x170 fs/splice.c:1059
 do_sendfile+0x56a/0xba0 fs/read_write.c:1540
 __do_sys_sendfile64 fs/read_write.c:1601 [inline]
 __se_sys_sendfile64 fs/read_write.c:1587 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1587
 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: 27493 Comm: syz-executor.1 Not tainted 5.9.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (9):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-upstream-kcsan-gce 2020/09/04 21:42 upstream c70672d8d316 abf9ba4f .config console log report
ci2-upstream-kcsan-gce 2020/08/22 20:36 upstream c3d8f220d012 1da71ab0 .config console log report
ci2-upstream-kcsan-gce 2020/08/19 12:44 upstream 18445bf405cb db787902 .config console log report
ci2-upstream-kcsan-gce 2020/08/13 23:53 upstream 990f227371a4 54ce1ed6 .config console log report
ci2-upstream-kcsan-gce 2020/07/14 20:26 upstream e9919e11e219 6f458026 .config console log report
ci2-upstream-kcsan-gce 2020/07/11 10:41 upstream 1df0d8960499 7ba05d2d .config console log report
ci2-upstream-kcsan-gce 2020/07/10 21:28 upstream a581387e415b 18d18b59 .config console log report
ci2-upstream-kcsan-gce 2020/07/07 18:47 upstream bfe91da29bfa 08fc4ef1 .config console log report
ci2-upstream-kcsan-gce 2020/07/01 19:04 upstream 7c30b859a947 39acb39d .config console log report
* Struck through repros no longer work on HEAD.