[PATCH V2] staging: vc04_services: handle kzalloc failure

From: Nicholas Mc Guire
Date: Thu Apr 18 2019 - 19:37:10 EST


The kzalloc here was being used without checking the return - if the
kzalloc fails return VCHIQ_ERROR. The call-site of
vchiq_platform_init_state() vchiq_init_state() was not responding
to an allocation failure so checks for != VCHIQ_SUCCESS
and pass VCHIQ_ERROR up to vchiq_platform_init() which then
will fail with -EINVAL.

Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
Reported-by: kbuild test robot <lkp@xxxxxxxxx>
---

Problem located with experimental coccinelle script

V2: The != VCHIQ_SUCCES went unnoticed not clear how I did that as
building drivers/staging/vc04_services/vchiq.o seemed to have succeeded
anyway kbuild test found it. This is one of the disadvantages if one
can not make path/file.o due to missing Makefiles and is required to
build entire directories for compile-testing, I suspect that I did not
clean the directory before compile-testing the patch.


Patch was compile-tested with: bcm2835_defconfig (implies BCM2835_VCHIQ=m)
(with sparse warning:
CHECK drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c:410:29: warning: incorrect type in argument 1 (different address spaces)
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c:410:29: expected void const *x
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c:410:29: got char [noderef] <asn:1> *buf
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c:416:63: warning: incorrect type in argument 1 (different address spaces)
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c:416:63: expected void const *addr
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c:416:63: got char [noderef] <asn:1> *
CC [M] drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.o
Q: should this buf have been remapped to user space e.g. remap_vmalloc_range ?

Patch is against 5.1-rc5 (localversion next is 20190417)

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c | 3 +++
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c | 2 ++
2 files changed, 5 insertions(+)

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
index 31eb7d5..a9a2291 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
@@ -179,6 +179,9 @@ vchiq_platform_init_state(struct vchiq_state *state)
struct vchiq_2835_state *platform_state;

state->platform_state = kzalloc(sizeof(*platform_state), GFP_KERNEL);
+ if (!state->platform_state)
+ return VCHIQ_ERROR;
+
platform_state = (struct vchiq_2835_state *)state->platform_state;

platform_state->inited = 1;
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
index 6057a90..92e6221 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
@@ -2209,6 +2209,8 @@ vchiq_init_state(struct vchiq_state *state, struct vchiq_slot_zero *slot_zero)
local->debug[DEBUG_ENTRIES] = DEBUG_MAX;

status = vchiq_platform_init_state(state);
+ if (status != VCHIQ_SUCCESS)
+ return VCHIQ_ERROR;

/*
bring up slot handler thread
--
2.1.4