jbd: fix oops in jbd_journal_init_inode() on corrupted fs

On 32-bit system with CONFIG_LBD getblk can fail because provided block
number is too big. Make JBD gracefully handle that.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: <dmaciejak@fortinet.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 24 insertions, 10 deletions

diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
index e79c07812afa..737f7246a4b5 100644
--- a/fs/jbd/journal.c
+++ b/fs/jbd/journal.c
@@ -637,6 +637,8 @@ struct journal_head *journal_get_descriptor_buffer(journal_t *journal)
                 return NULL;
 
         bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
+        if (!bh)
+                return NULL;
         lock_buffer(bh);
         memset(bh->b_data, 0, journal->j_blocksize);
         set_buffer_uptodate(bh);
@@ -733,9 +735,7 @@ journal_t * journal_init_dev(struct block_device *bdev,
         if (!journal->j_wbuf) {
                 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
                         __func__);
-                kfree(journal);
-                journal = NULL;
-                goto out;
+                goto out_err;
         }
         journal->j_dev = bdev;
         journal->j_fs_dev = fs_dev;
@@ -743,11 +743,19 @@ journal_t * journal_init_dev(struct block_device *bdev,
         journal->j_maxlen = len;
 
         bh = __getblk(journal->j_dev, start, journal->j_blocksize);
-        J_ASSERT(bh != NULL);
+        if (!bh) {
+                printk(KERN_ERR
+                       "%s: Cannot get buffer for journal superblock\n",
+                       __func__);
+                goto out_err;
+        }
         journal->j_sb_buffer = bh;
         journal->j_superblock = (journal_superblock_t *)bh->b_data;
-out:
+
         return journal;
+out_err:
+        kfree(journal);
+        return NULL;
 }
 
 /**
@@ -787,8 +795,7 @@ journal_t * journal_init_inode (struct inode *inode)
         if (!journal->j_wbuf) {
                 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
                         __func__);
-                kfree(journal);
-                return NULL;
+                goto out_err;
         }
 
         err = journal_bmap(journal, 0, &blocknr);
@@ -796,16 +803,23 @@ journal_t * journal_init_inode (struct inode *inode)
         if (err) {
                 printk(KERN_ERR "%s: Cannnot locate journal superblock\n",
                        __func__);
-                kfree(journal);
-                return NULL;
+                goto out_err;
         }
 
         bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
-        J_ASSERT(bh != NULL);
+        if (!bh) {
+                printk(KERN_ERR
+                       "%s: Cannot get buffer for journal superblock\n",
+                       __func__);
+                goto out_err;
+        }
         journal->j_sb_buffer = bh;
         journal->j_superblock = (journal_superblock_t *)bh->b_data;
 
         return journal;
+out_err:
+        kfree(journal);
+        return NULL;
 }
 
 /*