Hello,
syzbot found the following crash on:
HEAD commit: 36756079 x86, kcsan: Enable KCSAN for x86
git tree:
https://github.com/google/ktsan.git kcsan
console output:
https://syzkaller.appspot.com/x/log.txt?x=11b88620e00000
kernel config:
https://syzkaller.appspot.com/x/.config?x=c0906aa620713d80
dashboard link:
https://syzkaller.appspot.com/bug?extid=4c6f0606244957a58652
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [
adilger...@dilger.ca
clang-bu...@googlegroups.com linux...@vger.kernel.org
linux-...@vger.kernel.org ty...@mit.edu el...@google.com]
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by:
syzbot+4c6f06...@syzkaller.appspotmail.com
==================================================================
BUG: KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set
write to 0xffff88821ff8c04e of 2 bytes by task 7300 on cpu 1:
ext4_free_inodes_set+0x29/0x90 fs/ext4/super.c:318
ext4_free_inode+0x675/0xaa0 fs/ext4/ialloc.c:320
ext4_evict_inode+0x9a9/0xdb0 fs/ext4/inode.c:333
evict+0x244/0x410 fs/inode.c:571
iput_final fs/inode.c:1560 [inline]
iput+0x362/0x4a0 fs/inode.c:1586
dentry_unlink_inode+0x27a/0x2f0 fs/dcache.c:374
d_delete fs/dcache.c:2449 [inline]
d_delete+0xdb/0xe0 fs/dcache.c:2438
vfs_rmdir fs/namei.c:3892 [inline]
vfs_rmdir+0x2e2/0x300 fs/namei.c:3857
do_rmdir+0x2cb/0x300 fs/namei.c:3940
__do_sys_rmdir fs/namei.c:3958 [inline]
__se_sys_rmdir fs/namei.c:3956 [inline]
__x64_sys_rmdir+0x2f/0x40 fs/namei.c:3956
do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x44/0xa9
read to 0xffff88821ff8c04e of 2 bytes by task 7493 on cpu 0:
ext4_free_inodes_count+0x26/0x90 fs/ext4/super.c:262
__ext4_new_inode+0xb9f/0x3070 fs/ext4/ialloc.c:896
ext4_symlink+0x30e/0x970 fs/ext4/namei.c:3262
vfs_symlink fs/namei.c:4127 [inline]
vfs_symlink+0x218/0x310 fs/namei.c:4113
do_symlinkat+0x1a5/0x1e0 fs/namei.c:4154
__do_sys_symlink fs/namei.c:4173 [inline]
__se_sys_symlink fs/namei.c:4171 [inline]
__x64_sys_symlink+0x3f/0x50 fs/namei.c:4171
do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7493 Comm: syz-executor.1 Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
==================================================================
---
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