jbd2: Fix oops in jbd2_journal_init_inode() on corrupted fs
On 32-bit system with CONFIG_LBD getblk can fail because provided
block number is too big. Add error checks so we fail gracefully if
getblk() returns NULL (which can also happen on memory allocation
failures).
Thanks to David Maciejak from Fortinet's FortiGuard Global Security
Research Team for reporting this bug.
http://bugzilla.kernel.org/show_bug.cgi?id=12370
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
cc: stable@kernel.org
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index fe20e40..2932c8f 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -632,6 +632,8 @@
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);
@@ -1021,15 +1023,14 @@
/* journal descriptor can store up to n blocks -bzzz */
journal->j_blocksize = blocksize;
+ jbd2_stats_proc_init(journal);
n = journal->j_blocksize / sizeof(journal_block_tag_t);
journal->j_wbufsize = n;
journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
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;
@@ -1039,14 +1040,22 @@
p = journal->j_devname;
while ((p = strchr(p, '/')))
*p = '!';
- jbd2_stats_proc_init(journal);
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:
+ jbd2_stats_proc_exit(journal);
+ kfree(journal);
+ return NULL;
}
/**
@@ -1094,9 +1103,7 @@
if (!journal->j_wbuf) {
printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
__func__);
- jbd2_stats_proc_exit(journal);
- kfree(journal);
- return NULL;
+ goto out_err;
}
err = jbd2_journal_bmap(journal, 0, &blocknr);
@@ -1104,17 +1111,24 @@
if (err) {
printk(KERN_ERR "%s: Cannnot locate journal superblock\n",
__func__);
- jbd2_stats_proc_exit(journal);
- 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:
+ jbd2_stats_proc_exit(journal);
+ kfree(journal);
+ return NULL;
}
/*