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KCSAN: data-race in ext4_alloc_da_blocks / ext4_da_release_space (2)

Status: auto-closed as invalid on 2020/12/30 22:47
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+be753d6f8bb6a273587a@syzkaller.appspotmail.com
First crash: 1236d, last: 1219d
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 ext4 1 1511d 1511d 0/26 auto-closed as invalid on 2020/04/18 06:44

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

write to 0xffff88800cf61518 of 4 bytes by task 12433 on cpu 1:
 ext4_da_release_space+0x9a/0x230 fs/ext4/inode.c:1515
 ext4_es_remove_extent+0xf8/0x1e0 fs/ext4/extents_status.c:1462
 ext4_ext_truncate+0xbd/0x160 fs/ext4/extents.c:4360
 ext4_truncate+0x82b/0xbb0 fs/ext4/inode.c:4254
 ext4_setattr+0xbac/0xf70 fs/ext4/inode.c:5493
 notify_change+0x7b3/0xa50 fs/attr.c:336
 do_truncate+0xe0/0x120 fs/open.c:64
 handle_truncate fs/namei.c:2910 [inline]
 do_open fs/namei.c:3256 [inline]
 path_openat+0x1a37/0x20a0 fs/namei.c:3369
 do_filp_open+0xbd/0x1d0 fs/namei.c:3396
 do_sys_openat2+0xa3/0x240 fs/open.c:1168
 do_sys_open fs/open.c:1184 [inline]
 __do_sys_openat fs/open.c:1200 [inline]
 __se_sys_openat fs/open.c:1195 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1195
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88800cf61518 of 4 bytes by task 12460 on cpu 0:
 ext4_alloc_da_blocks+0x1d/0x100 fs/ext4/inode.c:3122
 ext4_release_file+0x5b/0x1d0 fs/ext4/file.c:142
 __fput+0x243/0x4d0 fs/file_table.c:281
 ____fput+0x11/0x20 fs/file_table.c:314
 task_work_run+0x8e/0x110 kernel/task_work.c:151
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:164 [inline]
 exit_to_user_mode_prepare+0x13c/0x170 kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 12460 Comm: syz-executor.5 Not tainted 5.10.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/11/25 22:46 upstream fa02fcd94b0c 3f581b43 .config console log report info ci2-upstream-kcsan-gce
2020/11/08 17:11 upstream 4429f14aeea9 cba33199 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.