Re: [PATCH] ipmi: kcs_bmc: handle devm_kasprintf() failure case

From: Corey Minyard
Date: Tue Nov 27 2018 - 08:36:54 EST

On 11/21/18 9:08 AM, Nicholas Mc Guire wrote:
devm_kasprintf() may return NULL if internal allocation failed so this
assignment is not safe. Moved the error exit path and added the !NULL
which then allows the devres manager to take care of cleanup.

Added the original author. This looks correct to me, I've included it, but I would
like Haiyue to comment, if possible.



Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
Fixes: cd2315d471f4 ("ipmi: kcs_bmc: don't change device name")

Problem located with experimental coccinelle script

Patch was compile tested with: aspeed_g5_defconfig (implies

Patch is against 4.20-rc3 (localversion-next is next-20181121)

drivers/char/ipmi/kcs_bmc.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
index e6124bd..86d29d2 100644
--- a/drivers/char/ipmi/kcs_bmc.c
+++ b/drivers/char/ipmi/kcs_bmc.c
@@ -440,12 +440,13 @@ struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv, u32 channel)
kcs_bmc->data_in = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
kcs_bmc->data_out = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
kcs_bmc->kbuffer = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
- if (!kcs_bmc->data_in || !kcs_bmc->data_out || !kcs_bmc->kbuffer)
- return NULL;
kcs_bmc->miscdev.minor = MISC_DYNAMIC_MINOR;
kcs_bmc-> = devm_kasprintf(dev, GFP_KERNEL, "%s%u",
DEVICE_NAME, channel);
+ if (!kcs_bmc->data_in || !kcs_bmc->data_out || !kcs_bmc->kbuffer ||
+ !kcs_bmc->
+ return NULL;
kcs_bmc->miscdev.fops = &kcs_bmc_fops;
return kcs_bmc;