Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.7 281/376] ext4: fix buffer_head refcnt leak when ext4_iget() fails | Date | Fri, 19 Jun 2020 16:33:19 +0200 |
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From: Xiyu Yang <xiyuyang19@fudan.edu.cn>
commit 3bbd0ef26098d241dc59ee77ba14b7dab0df0786 upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/ext4/ialloc.c | 1 + 1 file changed, 1 insertion(+)
--- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -1246,6 +1246,7 @@ struct inode *ext4_orphan_get(struct sup ext4_error_err(sb, -err, "couldn't read orphan inode %lu (err %d)", ino, err); + brelse(bitmap_bh); return inode; }
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