syzbot


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

Status: auto-closed as invalid on 2021/11/02 13:17
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 499d, last: 426d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in filemap_read / generic_write_end (3) 257 3h08m 300d 0/24 moderation: reported on 2022/01/31 16:57
upstream KCSAN: data-race in filemap_read / generic_write_end 3 556d 565d 0/24 auto-closed as invalid on 2021/06/25 01:21

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

write to 0xffff8881238a2718 of 8 bytes by task 10378 on cpu 1:
 i_size_write include/linux/fs.h:916 [inline]
 generic_write_end+0x96/0x180 fs/buffer.c:2186
 ext4_da_write_end+0x59b/0x730 fs/ext4/inode.c:3116
 generic_perform_write+0x251/0x3e0 mm/filemap.c:3781
 ext4_buffered_write_iter+0x305/0x400 fs/ext4/file.c:269
 ext4_file_write_iter+0x2e7/0x11f0
 call_write_iter include/linux/fs.h:2163 [inline]
 do_iter_readv_writev+0x2de/0x380 fs/read_write.c:729
 do_iter_write+0x192/0x5c0 fs/read_write.c:855
 vfs_iter_write+0x4c/0x70 fs/read_write.c:896
 iter_file_splice_write+0x43a/0x790 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x650 fs/splice.c:891
 do_splice_direct+0x106/0x190 fs/splice.c:979
 do_sendfile+0x63e/0xbb0 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1314 [inline]
 __se_sys_sendfile64 fs/read_write.c:1300 [inline]
 __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1300
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881238a2718 of 8 bytes by task 10389 on cpu 0:
 i_size_read include/linux/fs.h:894 [inline]
 filemap_read+0xd55/0x1220 mm/filemap.c:2640
 generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2779
 ext4_file_read_iter+0x1db/0x290
 call_read_iter include/linux/fs.h:2157 [inline]
 generic_file_splice_read+0x24f/0x330 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
 do_splice_direct+0x106/0x190 fs/splice.c:979
 do_sendfile+0x63e/0xbb0 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1314 [inline]
 __se_sys_sendfile64 fs/read_write.c:1300 [inline]
 __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1300
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000ad3400 -> 0x0000000000ad4000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10389 Comm: syz-executor.0 Not tainted 5.15.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (8):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/09/28 13:14 upstream 0513e464f900 d82cb927 .config log report info KCSAN: data-race in filemap_read / generic_write_end
ci2-upstream-kcsan-gce 2021/09/17 16:46 upstream ddf21bd8ab98 70b76c1d .config log report info KCSAN: data-race in filemap_read / generic_write_end
ci2-upstream-kcsan-gce 2021/08/20 02:17 upstream f87d64319e6f b599f2fc .config log report info KCSAN: data-race in filemap_read / generic_write_end
ci2-upstream-kcsan-gce 2021/08/14 01:36 upstream dfa377c35d70 2489ab88 .config log report info KCSAN: data-race in filemap_read / generic_write_end
ci2-upstream-kcsan-gce 2021/08/12 19:18 upstream f8fbb47c6e86 c551a195 .config log report info KCSAN: data-race in filemap_read / generic_write_end
ci2-upstream-kcsan-gce 2021/08/03 17:15 upstream d5ad8ec3cfb5 6c236867 .config log report info KCSAN: data-race in filemap_read / generic_write_end
ci2-upstream-kcsan-gce 2021/07/24 09:45 upstream f0fddcec6b62 4d1b57d4 .config log report info KCSAN: data-race in filemap_read / generic_write_end
ci2-upstream-kcsan-gce 2021/07/17 11:35 upstream d980cc0620ae f115ae98 .config log report info KCSAN: data-race in filemap_read / generic_write_end
* Struck through repros no longer work on HEAD.