hfsplus: 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>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 10 insertions, 6 deletions

diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index acaef57e3606..2c1a72287fb5 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -73,11 +73,13 @@ struct inode *hfsplus_iget(struct super_block *sb, unsigned long ino)
 
         if (inode->i_ino >= HFSPLUS_FIRSTUSER_CNID ||
             inode->i_ino == HFSPLUS_ROOT_CNID) {
-                hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
-                err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
-                if (!err)
-                        err = hfsplus_cat_read_inode(inode, &fd);
-                hfs_find_exit(&fd);
+                err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
+                if (!err) {
+                        err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
+                        if (!err)
+                                err = hfsplus_cat_read_inode(inode, &fd);
+                        hfs_find_exit(&fd);
+                }
         } else {
                 err = hfsplus_system_read_inode(inode);
         }
@@ -456,7 +458,9 @@ static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
 
         str.len = sizeof(HFSP_HIDDENDIR_NAME) - 1;
         str.name = HFSP_HIDDENDIR_NAME;
-        hfs_find_init(sbi->cat_tree, &fd);
+        err = hfs_find_init(sbi->cat_tree, &fd);
+        if (err)
+                goto out_put_root;
         hfsplus_cat_build_key(sb, fd.search_key, HFSPLUS_ROOT_CNID, &str);
         if (!hfs_brec_read(&fd, &entry, sizeof(entry))) {
                 hfs_find_exit(&fd);