hfs: add error checking for hfs_find_init()

hfs_find_init() may fail with ENOMEM, but there are places, where the
returned value is not checked.  The consequences can be very unpleasant,
e.g.  kfree uninitialized pointer and inappropriate mutex unlocking.

The patch adds checks for errors in hfs_find_init().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 2 deletions

diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 3031dfdd2358..0847471ff04f 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -416,9 +416,12 @@ int hfs_write_inode(struct inode *inode, struct writeback_control *wbc)
         struct inode *main_inode = inode;
         struct hfs_find_data fd;
         hfs_cat_rec rec;
+        int res;
 
         dprint(DBG_INODE, "hfs_write_inode: %lu\n", inode->i_ino);
-        hfs_ext_write_extent(inode);
+        res = hfs_ext_write_extent(inode);
+        if (res)
+                return res;
 
         if (inode->i_ino < HFS_FIRSTUSER_CNID) {
                 switch (inode->i_ino) {
@@ -515,7 +518,11 @@ static struct dentry *hfs_file_lookup(struct inode *dir, struct dentry *dentry,
         if (!inode)
                 return ERR_PTR(-ENOMEM);
 
-        hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
+        res = hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
+        if (res) {
+                iput(inode);
+                return ERR_PTR(res);
+        }
         fd.search_key->cat = HFS_I(dir)->cat_key;
         res = hfs_brec_read(&fd, &rec, sizeof(rec));
         if (!res) {