On Tue, Sep 5, 2017 at 9:51 AM, Colin King <[email protected]> wrote: > From: Colin Ian King <[email protected]> > > 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: 5e405595e5bf ("ext4: perform dax_device lookup at mount") > Signed-off-by: Colin Ian King <[email protected]> > --- > fs/ext4/super.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 0e63fcd12c5b..71b9a667e1bc 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -3422,10 +3422,10 @@ 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)
Thanks, this looks obviously correct to me. I'll append to the branch with 5e405595e5bf.
