syzbot


KCSAN: data-race in ext4_alloc_da_blocks / ext4_da_reserve_space (3)

Status: closed as invalid on 2020/06/18 14:24
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 865d, last: 845d
similar bugs (6):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_alloc_da_blocks / ext4_da_reserve_space (4) 10 722d 823d 0/24 auto-closed as invalid on 2020/11/07 06:53
upstream KCSAN: data-race in ext4_alloc_da_blocks / ext4_da_reserve_space 2 1049d 1066d 0/24 closed as invalid on 2019/11/19 14:44
upstream KCSAN: data-race in ext4_alloc_da_blocks / ext4_da_reserve_space (6) 23 440d 584d 0/24 auto-closed as invalid on 2021/08/16 16:28
upstream KCSAN: data-race in ext4_alloc_da_blocks / ext4_da_reserve_space (7) 16 289d 397d 0/24 auto-closed as invalid on 2022/01/14 22:09
upstream KCSAN: data-race in ext4_alloc_da_blocks / ext4_da_reserve_space (5) 1 621d 621d 0/24 auto-closed as invalid on 2021/02/16 17:07
upstream KCSAN: data-race in ext4_alloc_da_blocks / ext4_da_reserve_space (2) 7 955d 1020d 0/24 auto-closed as invalid on 2020/04/23 17:25

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_alloc_da_blocks / ext4_da_reserve_space

write to 0xffff8880b26fdc78 of 4 bytes by task 29142 on cpu 1:
 ext4_da_reserve_space+0x132/0x270 fs/ext4/inode.c:1468
 ext4_insert_delayed_block fs/ext4/inode.c:1631 [inline]
 ext4_da_map_blocks fs/ext4/inode.c:1746 [inline]
 ext4_da_get_block_prep+0x87e/0xa50 fs/ext4/inode.c:1810
 ext4_block_write_begin+0x336/0xbd0 fs/ext4/inode.c:1053
 ext4_da_write_begin+0x220/0xa10 fs/ext4/inode.c:2995
 generic_perform_write+0x13a/0x320 mm/filemap.c:3302
 ext4_buffered_write_iter+0x14e/0x280 fs/ext4/file.c:270
 ext4_file_write_iter+0xf4/0xd30 fs/ext4/file.c:642
 call_write_iter include/linux/fs.h:1907 [inline]
 do_iter_readv_writev+0x4a7/0x5d0 fs/read_write.c:694
 do_iter_write fs/read_write.c:999 [inline]
 do_iter_write+0x137/0x3a0 fs/read_write.c:980
 vfs_iter_write+0x56/0x80 fs/read_write.c:1040
 iter_file_splice_write+0x530/0x830 fs/splice.c:760
 do_splice_from fs/splice.c:863 [inline]
 direct_splice_actor+0x97/0xb0 fs/splice.c:1037
 splice_direct_to_actor+0x22f/0x540 fs/splice.c:992
 do_splice_direct+0x152/0x1d0 fs/splice.c:1080
 do_sendfile+0x380/0x800 fs/read_write.c:1521
 __do_sys_sendfile64 fs/read_write.c:1576 [inline]
 __se_sys_sendfile64 fs/read_write.c:1568 [inline]
 __x64_sys_sendfile64+0xb8/0x140 fs/read_write.c:1568
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880b26fdc78 of 4 bytes by task 29141 on cpu 0:
 ext4_alloc_da_blocks+0x48/0x170 fs/ext4/inode.c:3110
 ext4_release_file+0x107/0x200 fs/ext4/file.c:142
 __fput+0x1e9/0x500 fs/file_table.c:280
 ____fput+0x1b/0x30 fs/file_table.c:313
 task_work_run+0xba/0x120 kernel/task_work.c:123
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2ae/0x2c0 arch/x86/entry/common.c:165
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x38b/0x3b0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 29141 Comm: syz-executor.5 Not tainted 5.7.0-rc1-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 2020/06/02 08:20 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a0331e89 .config log report
ci2-upstream-kcsan-gce 2020/05/14 01:07 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a885920d .config log report
* Struck through repros no longer work on HEAD.