syzbot


KCSAN: data-race in __writeback_single_inode / ext4_sync_file (5)

Status: auto-closed as invalid on 2021/12/16 21:26
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 391d, last: 391d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __writeback_single_inode / ext4_sync_file (4) 6 470d 509d 0/24 auto-closed as invalid on 2021/09/28 17:33
upstream KCSAN: data-race in __writeback_single_inode / ext4_sync_file 15 1018d 1087d 0/24 auto-closed as invalid on 2020/05/03 19:14
upstream KCSAN: data-race in __writeback_single_inode / ext4_sync_file (3) 72 551d 730d 0/24 auto-closed as invalid on 2021/07/09 15:43
upstream KCSAN: data-race in __writeback_single_inode / ext4_sync_file (2) 3 914d 934d 0/24 closed as invalid on 2020/06/18 14:13

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __writeback_single_inode / ext4_sync_file

write to 0xffff88813a0e9a90 of 8 bytes by task 25874 on cpu 0:
 __writeback_single_inode+0x1e9/0x4d0 fs/fs-writeback.c:1652
 writeback_single_inode+0x11f/0x3d0 fs/fs-writeback.c:1729
 sync_inode_metadata+0x57/0x80 fs/fs-writeback.c:2749
 ext4_fsync_nojournal fs/ext4/fsync.c:92 [inline]
 ext4_sync_file+0x359/0x6e0 fs/ext4/fsync.c:170
 vfs_fsync_range+0x107/0x120 fs/sync.c:182
 generic_write_sync include/linux/fs.h:2956 [inline]
 ext4_buffered_write_iter+0x322/0x380 fs/ext4/file.c:277
 ext4_file_write_iter+0x2e7/0x1200
 call_write_iter include/linux/fs.h:2162 [inline]
 do_iter_readv_writev+0x2de/0x380 fs/read_write.c:725
 do_iter_write+0x192/0x5c0 fs/read_write.c:851
 vfs_iter_write+0x4c/0x70 fs/read_write.c:892
 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+0x675/0xc40 fs/read_write.c:1245
 __do_sys_sendfile64 fs/read_write.c:1310 [inline]
 __se_sys_sendfile64 fs/read_write.c:1296 [inline]
 __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88813a0e9a90 of 8 bytes by task 25731 on cpu 1:
 ext4_fsync_nojournal fs/ext4/fsync.c:87 [inline]
 ext4_sync_file+0x294/0x6e0 fs/ext4/fsync.c:170
 vfs_fsync_range+0x107/0x120 fs/sync.c:182
 generic_write_sync include/linux/fs.h:2956 [inline]
 ext4_buffered_write_iter+0x322/0x380 fs/ext4/file.c:277
 ext4_file_write_iter+0x2e7/0x1200
 call_write_iter include/linux/fs.h:2162 [inline]
 do_iter_readv_writev+0x2de/0x380 fs/read_write.c:725
 do_iter_write+0x192/0x5c0 fs/read_write.c:851
 vfs_iter_write+0x4c/0x70 fs/read_write.c:892
 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+0x675/0xc40 fs/read_write.c:1245
 __do_sys_sendfile64 fs/read_write.c:1310 [inline]
 __se_sys_sendfile64 fs/read_write.c:1296 [inline]
 __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000000084 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25731 Comm: syz-executor.5 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/11/11 21:26 upstream debe436e77c7 75b04091 .config log report info KCSAN: data-race in __writeback_single_inode / ext4_sync_file
* Struck through repros no longer work on HEAD.