jbd2: Fix oops in jbd2_journal_init_inode() on corrupted fs From: Jan Kara 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 Signed-off-by: "Theodore Ts'o" cc: stable@kernel.org --- fs/jbd2/journal.c | 40 +++++++++++++++++++++++++++------------- 1 files changed, 27 insertions(+), 13 deletions(-) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index f6bff9d..a263f76 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -650,6 +650,8 @@ struct journal_head *jbd2_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); @@ -1035,15 +1037,14 @@ journal_t * jbd2_journal_init_dev(struct block_device *bdev, /* 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; @@ -1053,14 +1054,22 @@ journal_t * jbd2_journal_init_dev(struct block_device *bdev, 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; } /** @@ -1108,9 +1117,7 @@ journal_t * jbd2_journal_init_inode (struct inode *inode) 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); @@ -1118,17 +1125,24 @@ journal_t * jbd2_journal_init_inode (struct inode *inode) 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; } /* -- 1.6.0.2