syzbot


KCSAN: data-race in ext4_mb_free_metadata / ext4_should_retry_alloc (2)

Status: auto-closed as invalid on 2022/01/23 07:11
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 349d, last: 349d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_mb_free_metadata / ext4_should_retry_alloc (3) 1 207d 207d 0/24 closed as invalid on 2022/05/13 11:20
upstream KCSAN: data-race in ext4_mb_free_metadata / ext4_should_retry_alloc 1 409d 409d 0/24 auto-closed as invalid on 2021/11/24 05:46

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_mb_free_metadata / ext4_should_retry_alloc

write to 0xffff8881031822e4 of 4 bytes by task 21327 on cpu 1:
 ext4_mb_free_metadata+0x3f1/0x450 fs/ext4/mballoc.c:5743
 ext4_free_blocks+0x112b/0x1b00 fs/ext4/mballoc.c:6042
 ext4_remove_blocks+0x7fb/0xa10 fs/ext4/extents.c:2541
 ext4_ext_rm_leaf+0x6a7/0xef0 fs/ext4/extents.c:2707
 ext4_ext_remove_space+0x956/0x14c0 fs/ext4/extents.c:2955
 ext4_ext_truncate+0xfe/0x170 fs/ext4/extents.c:4417
 ext4_truncate+0x76e/0xae0 fs/ext4/inode.c:4201
 ext4_setattr+0xaff/0xf20 fs/ext4/inode.c:5474
 notify_change+0x8a3/0xac0 fs/attr.c:410
 do_truncate+0xf7/0x140 fs/open.c:64
 handle_truncate fs/namei.c:3082 [inline]
 do_open fs/namei.c:3430 [inline]
 path_openat+0x191f/0x1eb0 fs/namei.c:3559
 do_filp_open+0x105/0x220 fs/namei.c:3586
 do_sys_openat2+0xb5/0x2b0 fs/open.c:1212
 do_sys_open fs/open.c:1228 [inline]
 __do_sys_openat fs/open.c:1244 [inline]
 __se_sys_openat fs/open.c:1239 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1239
 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 0xffff8881031822e4 of 4 bytes by task 21321 on cpu 0:
 ext4_should_retry_alloc+0xc2/0x170 fs/ext4/balloc.c:655
 ext4_alloc_file_blocks+0x6ab/0x730 fs/ext4/extents.c:4503
 ext4_fallocate+0x2a7/0x540 fs/ext4/extents.c:4753
 vfs_fallocate+0x486/0x720 fs/open.c:307
 do_vfs_ioctl+0x13cb/0x14a0 fs/ioctl.c:853
 __do_sys_ioctl fs/ioctl.c:872 [inline]
 __se_sys_ioctl+0x83/0x140 fs/ioctl.c:860
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:860
 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: 0x00012b5d -> 0x00012ba4

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 21321 Comm: syz-executor.5 Not tainted 5.16.0-rc5-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 2021/12/19 07:03 upstream 3f667b5d4053 44068e19 .config log report info KCSAN: data-race in ext4_mb_free_metadata / ext4_should_retry_alloc
* Struck through repros no longer work on HEAD.