[PATCH] md: Combine two kmalloc() calls into one in sb_equal()

From: SF Markus Elfring
Date: Fri Dec 09 2016 - 13:30:40 EST


From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
Date: Fri, 9 Dec 2016 19:09:13 +0100

The function "kmalloc" was called in one case by the function "sb_equal"
without checking immediately if it failed.
This issue was detected by using the Coccinelle software.

Perform the desired memory allocation (and release at the end)
by a single function call instead.

Fixes: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ("Linux-2.6.12-rc2")

Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/md/md.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index b088668269b0..86caf2536255 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -843,15 +843,12 @@ static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
int ret;
mdp_super_t *tmp1, *tmp2;

- tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
- tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
-
- if (!tmp1 || !tmp2) {
- ret = 0;
- goto abort;
- }
+ tmp1 = kmalloc(2 * sizeof(*tmp1), GFP_KERNEL);
+ if (!tmp1)
+ return 0;

*tmp1 = *sb1;
+ tmp2 = tmp1 + 1;
*tmp2 = *sb2;

/*
@@ -861,9 +858,7 @@ static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
tmp2->nr_disks = 0;

ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
-abort:
kfree(tmp1);
- kfree(tmp2);
return ret;
}

--
2.11.0