ext4_orphan_get() invokes ext4_read_inode_bitmap(), which returns a
reference of the specified buffer_head object to "bitmap_bh" with
increased refcnt.
When ext4_orphan_get() returns, local variable "bitmap_bh" becomes
invalid, so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of
ext4_orphan_get(). When ext4_iget() fails, the function forgets to
decrease the refcnt increased by ext4_read_inode_bitmap(), causing a
refcnt leak.
Fix this issue by calling brelse() when ext4_iget() fails.
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/1587618568-13418-1-git-send-email-xiyuyang19@fudan.edu.cn
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4_error_err(sb, -err,
"couldn't read orphan inode %lu (err %d)",
ino, err);
+ brelse(bitmap_bh);
return inode;
}