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KCSAN: data-race in ext4_alloc_da_blocks / ext4_da_release_space

Status: auto-closed as invalid on 2020/04/18 06:44
Subsystems: ext4
[Documentation on labels]
First crash: 1510d, last: 1510d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_alloc_da_blocks / ext4_da_release_space (2) ext4 2 1219d 1207d 0/26 auto-closed as invalid on 2020/12/30 22:47

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_alloc_da_blocks / ext4_da_release_space

write to 0xffff8880810dccf0 of 4 bytes by task 25272 on cpu 0:
 ext4_da_release_space+0x102/0x2c0 fs/ext4/inode.c:1502
 ext4_es_remove_extent+0xd1/0x1f0 fs/ext4/extents_status.c:1441
 ext4_ext_truncate+0xca/0x130 fs/ext4/extents.c:4611
 ext4_truncate+0x5c8/0x9d0 fs/ext4/inode.c:4175
 ext4_setattr+0xdda/0x1670 fs/ext4/inode.c:5333
 notify_change+0x7e1/0xaa0 fs/attr.c:337
 do_truncate+0xfb/0x180 fs/open.c:64
 handle_truncate fs/namei.c:3015 [inline]
 do_last fs/namei.c:3426 [inline]
 path_openat+0x13e8/0x3580 fs/namei.c:3537
 do_filp_open+0x11e/0x1b0 fs/namei.c:3567
 do_sys_open+0x3b3/0x4f0 fs/open.c:1097
 ksys_open include/linux/syscalls.h:1385 [inline]
 __do_sys_creat fs/open.c:1155 [inline]
 __se_sys_creat fs/open.c:1153 [inline]
 __x64_sys_creat+0x45/0x60 fs/open.c:1153
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880810dccf0 of 4 bytes by task 25271 on cpu 1:
 ext4_alloc_da_blocks+0x4b/0x180 fs/ext4/inode.c:3111
 ext4_release_file+0x10d/0x210 fs/ext4/file.c:141
 __fput+0x1e1/0x520 fs/file_table.c:280
 ____fput+0x1f/0x30 fs/file_table.c:313
 task_work_run+0xf6/0x130 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2b4/0x2c0 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25271 Comm: syz-executor.0 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/02/08 06:35 https://github.com/google/ktsan.git kcsan 6cccb8ba35bd 06150bf1 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.