KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c2131f7e Merge tag 'gfs2-v5.13-rc2-fixes' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=179f6bcbd00000
kernel config: https://syzkaller.appspot.com/x/.config?x=7e844fa8c959d01b
dashboard link: https://syzkaller.appspot.com/bug?extid=23e6d63bad68d0ee8fe2
compiler: Debian clang version 11.0.1-2
CC: [adilger...@dilger.ca linux...@vger.kernel.org linux-...@vger.kernel.org ty...@mit.edu]

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+23e6d6...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks

write to 0xffff888101360b54 of 4 bytes by task 1749 on cpu 0:
mb_free_blocks+0x156/0xb40 fs/ext4/mballoc.c:1798
ext4_free_blocks+0x1418/0x1b50 fs/ext4/mballoc.c:5988
ext4_remove_blocks+0x61a/0x800 fs/ext4/extents.c:2498
ext4_ext_rm_leaf+0x670/0xd20 fs/ext4/extents.c:2664
ext4_ext_remove_space+0x901/0x1300 fs/ext4/extents.c:2912
ext4_ext_truncate+0xfe/0x170 fs/ext4/extents.c:4370
ext4_truncate+0x76e/0xa80 fs/ext4/inode.c:4262
ext4_evict_inode+0xa54/0xdb0 fs/ext4/inode.c:288
evict+0x1c8/0x3c0 fs/inode.c:584
iput_final fs/inode.c:1660 [inline]
iput+0x433/0x590 fs/inode.c:1686
dentry_unlink_inode+0x23a/0x260 fs/dcache.c:376
d_delete+0x78/0xe0 fs/dcache.c:2505
vfs_rmdir+0x2a6/0x2c0 fs/namei.c:3909
do_rmdir+0x14a/0x2e0 fs/namei.c:3958
__do_sys_rmdir fs/namei.c:3976 [inline]
__se_sys_rmdir fs/namei.c:3974 [inline]
__x64_sys_rmdir+0x2c/0x30 fs/namei.c:3974
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888101360b54 of 4 bytes by task 1751 on cpu 1:
ext4_mb_good_group_nolock fs/ext4/mballoc.c:2491 [inline]
ext4_mb_regular_allocator+0xae9/0x2520 fs/ext4/mballoc.c:2728
ext4_mb_new_blocks+0x762/0x1f90 fs/ext4/mballoc.c:5514
ext4_ext_map_blocks+0x1569/0x1f00 fs/ext4/extents.c:4238
ext4_map_blocks+0x70d/0xef0 fs/ext4/inode.c:638
ext4_getblk+0xb1/0x3d0 fs/ext4/inode.c:848
ext4_bread+0x28/0x130 fs/ext4/inode.c:900
ext4_append+0xd1/0x1c0 fs/ext4/namei.c:67
ext4_init_new_dir+0x177/0x500 fs/ext4/namei.c:2883
ext4_mkdir+0x329/0x760 fs/ext4/namei.c:2929
vfs_mkdir+0x2a4/0x370 fs/namei.c:3813
do_mkdirat+0x11d/0x200 fs/namei.c:3838
__do_sys_mkdir fs/namei.c:3856 [inline]
__se_sys_mkdir fs/namei.c:3854 [inline]
__x64_sys_mkdir+0x32/0x40 fs/namei.c:3854
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000595b -> 0x0000595c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1751 Comm: syz-executor.5 Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.