2018-08-24 10:58:11

by Nicholas Mc Guire

Subject: [PATCH] ARM: u300: add missing check for kmalloc

kmalloc return for bigrxbuf_virtual was not being checked - in case
of failure set status, cleanup bigtxbuf_virtual and baile out.

Signed-off-by: Nicholas Mc Guire <[email protected]>
Fixes: c7c8c78fdf6e ("ARM: 5667/3: U300 SSP/SPI board setup and test")
---

Issue found with experimental coccinelle script

Not sure about the checkpatch message:
CHECK: Comparison to NULL could be written "!bigrxbuf_virtual"
#32: FILE: arch/arm/mach-u300/dummyspichip.c:67:
+ if (bigrxbuf_virtual == NULL) {
As the current check for bigtxbuf_virtual uses == NULL that
was retained for consistency here.

Patch was compile tested with: u300_defconfig (implies MACH_U300_SPIDUMMY=y)

Patch is against 4.18 (localversion-next is next-20180824)

arch/arm/mach-u300/dummyspichip.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/arch/arm/mach-u300/dummyspichip.c b/arch/arm/mach-u300/dummyspichip.c
index 68fe986..ff293ee 100644
--- a/arch/arm/mach-u300/dummyspichip.c
+++ b/arch/arm/mach-u300/dummyspichip.c
@@ -62,7 +62,13 @@ static ssize_t dummy_looptest(struct device *dev,
status = -ENOMEM;
goto out;
}
+
bigrxbuf_virtual = kmalloc(DMA_TEST_SIZE, GFP_KERNEL);
+ if (bigrxbuf_virtual == NULL) {
+ kfree(bigtxbuf_virtual);
+ status = -ENOMEM;
+ goto out;
+ }

/* Fill TXBUF with some happy pattern */
memset(bigtxbuf_virtual, 0xAA, DMA_TEST_SIZE);
--
2.1.4

2018-09-05 09:10:50

by Linus Walleij

Subject: Re: [PATCH] ARM: u300: add missing check for kmalloc

On Fri, Aug 24, 2018 at 12:33 PM Nicholas Mc Guire <[email protected]> wrote:

> kmalloc return for bigrxbuf_virtual was not being checked - in case
> of failure set status, cleanup bigtxbuf_virtual and baile out.
>
> Signed-off-by: Nicholas Mc Guire <[email protected]>
> Fixes: c7c8c78fdf6e ("ARM: 5667/3: U300 SSP/SPI board setup and test")

I will delete this testchip instead. It is not in use.

Yours,
Linus Walleij

2018-09-05 11:23:28

by Nicholas Mc Guire

Subject: Re: [PATCH] ARM: u300: add missing check for kmalloc

On Wed, Sep 05, 2018 at 11:09:21AM +0200, Linus Walleij wrote:
> On Fri, Aug 24, 2018 at 12:33 PM Nicholas Mc Guire <[email protected]> wrote:
>
> > kmalloc return for bigrxbuf_virtual was not being checked - in case
> > of failure set status, cleanup bigtxbuf_virtual and baile out.
> >
> > Signed-off-by: Nicholas Mc Guire <[email protected]>
> > Fixes: c7c8c78fdf6e ("ARM: 5667/3: U300 SSP/SPI board setup and test")
>
> I will delete this testchip instead. It is not in use.
>
well that will for sure eliminate this bug reliably ;)

thx!
hofrat