Commit aed9eb1b authored Sep 05, 2017 by Colin Ian King Committed by Dan Williams Sep 05, 2017

ext4: fix null pointer dereference on sbi



In the case of a kzalloc failure when allocating sbi we end up
with a null pointer dereference on sbi when assigning sbi->s_daxdev.
Fix this by moving the assignment of sbi->s_daxdev to after the
null pointer check of sbi.

Detected by CoverityScan CID#1455379 ("Dereference before null check")

Fixes: 5e405595 ("ext4: perform dax_device lookup at mount")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

parent 9edcad53

fs/ext4/super.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3401,10 +3401,10 @@ static int ext4_fill_super(struct super_block sb, void data, int silent)
		unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
		ext4_group_t first_not_zeroed;

		sbi->s_daxdev = dax_dev;
		if ((data && !orig_data) \|\| !sbi)
		goto out_free_base;

		sbi->s_daxdev = dax_dev;
		sbi->s_blockgroup_lock =
		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
		if (!sbi->s_blockgroup_lock)

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