Messages in this thread Patch in this message | | | From | Xiyu Yang <> | Subject | [PATCH] ext4: Fix buffer_head refcnt leak when ext4_iget() fails | Date | Thu, 23 Apr 2020 13:09:27 +0800 |
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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> --- fs/ext4/ialloc.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index f95ee99091e4..2e4729ba17e6 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -1234,6 +1234,7 @@ struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino) ext4_set_errno(sb, -err); ext4_error(sb, "couldn't read orphan inode %lu (err %d)", ino, err); + brelse(bitmap_bh); return inode; } -- 2.7.4
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