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ext4: fix null pointer dereference on sbi

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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: 5e405595e5 ("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>
This commit is contained in:
Colin Ian King 2017-09-05 17:51:23 +01:00 committed by Dan Williams
parent 9edcad53d6
commit aed9eb1b21
1 changed files with 1 additions and 1 deletions
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2
fs/ext4/super.c
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@ -3401,10 +3401,10 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO; unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
ext4_group_t first_not_zeroed; ext4_group_t first_not_zeroed;
sbi->s_daxdev = dax_dev;
if ((data && !orig_data) || !sbi) if ((data && !orig_data) || !sbi)
goto out_free_base; goto out_free_base;
sbi->s_daxdev = dax_dev;
sbi->s_blockgroup_lock = sbi->s_blockgroup_lock =
kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL); kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
if (!sbi->s_blockgroup_lock) if (!sbi->s_blockgroup_lock)