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>

diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
index e79c078..737f724 100644 (file)
--- 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;
 }
 
 /*