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authorAndreas Dilger <adilger@dilger.ca>2012-05-28 17:02:25 -0400
committerTheodore Ts'o <tytso@mit.edu>2012-05-28 17:02:25 -0400
commit7e936b737211e6b54e34b71a827e56b872e958d8 (patch)
treeaca4b57eb1982d2cd21bcaa0cbabc45500f97026
parent967ac8af4475ce45474800709b12137aa7634c77 (diff)
ext4: disallow hard-linked directory in ext4_lookup
A hard-linked directory to its parent can cause the VFS to deadlock, and is a sign of a corrupted file system. So detect this case in ext4_lookup(), before the rmdir() lockup scenario can take place. Signed-off-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@kernel.org
-rw-r--r--fs/ext4/namei.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index a9fd5f48f3b..daf8260f0b0 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1330,6 +1330,12 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, stru
EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
return ERR_PTR(-EIO);
}
+ if (unlikely(ino == dir->i_ino)) {
+ EXT4_ERROR_INODE(dir, "'%.*s' linked to parent dir",
+ dentry->d_name.len,
+ dentry->d_name.name);
+ return ERR_PTR(-EIO);
+ }
inode = ext4_iget(dir->i_sb, ino);
if (inode == ERR_PTR(-ESTALE)) {
EXT4_ERROR_INODE(dir,