Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f613dfcb authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: check to make make sure bd_dev is set before dereferencing it 



There are some drivers which may not set bdev->bd_dev.  So make sure
it is non-NULL before dereferencing it.

Google-Bug-Id: 1773557

Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent cc937db7

fs/ext4/super.c

+13 −4
Original line number Diff line number Diff line
@@ -2304,6 +2304,8 @@ static ssize_t session_write_kbytes_show(struct ext4_attr *a, 
{

	struct super_block *sb = sbi->s_buddy_cache->i_sb;



	if (!sb->s_bdev->bd_part)

		return snprintf(buf, PAGE_SIZE, "0\n");

	return snprintf(buf, PAGE_SIZE, "%lu\n",

			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -

			 sbi->s_sectors_written_start) >> 1);
@@ -2314,6 +2316,8 @@ static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a, 
{

	struct super_block *sb = sbi->s_buddy_cache->i_sb;



	if (!sb->s_bdev->bd_part)

		return snprintf(buf, PAGE_SIZE, "0\n");

	return snprintf(buf, PAGE_SIZE, "%llu\n",

			(unsigned long long)(sbi->s_kbytes_written +

			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
@@ -2575,8 +2579,9 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) 
	sbi->s_resgid = EXT4_DEF_RESGID;

	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;

	sbi->s_sb_block = sb_block;

	sbi->s_sectors_written_start = part_stat_read(sb->s_bdev->bd_part,

						      sectors[1]);

	if (sb->s_bdev->bd_part)

		sbi->s_sectors_written_start =

			part_stat_read(sb->s_bdev->bd_part, sectors[1]);



	unlock_kernel();
@@ -3492,10 +3497,14 @@ static int ext4_commit_super(struct super_block *sb, int sync) 
	 */

	if (!(sb->s_flags & MS_RDONLY))

		es->s_wtime = cpu_to_le32(get_seconds());

	if (sb->s_bdev->bd_part)

		es->s_kbytes_written =

			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +

			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -

			      EXT4_SB(sb)->s_sectors_written_start) >> 1));

	else

		es->s_kbytes_written =

			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);

	ext4_free_blocks_count_set(es, percpu_counter_sum_positive(

					&EXT4_SB(sb)->s_freeblocks_counter));

	es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(