From: Shyam Sunder Reddy Padira <shyamsunderreddypadira@gmail.com>
To: gregkh@linuxfoundation.org
Cc: linux-kernel@vger.kernel.org, linux-staging@lists.linux.dev,
Shyam Sunder Reddy Padira <shyamsunderreddypadira@gmail.com>
Subject: [PATCH] staging: vme_user: check find_bridge() return value
Date: Wed, 6 May 2026 02:27:46 +0530 [thread overview]
Message-ID: <20260505205746.227144-1-shyamsunderreddypadira@gmail.com> (raw)
find_bridge() returns NULL when no matching bridge is found
for a given resource. Some call sites dereference the return
value without verifying it is non-NULL.
Add NULL checks before use to avoid potentail NULL pointer
dereferences.
Signed-off-by: Shyam Sunder Reddy Padira <shyamsunderreddypadira@gmail.com>
---
drivers/staging/vme_user/vme.c | 63 ++++++++++++++++++++++++++++++++++
1 file changed, 63 insertions(+)
diff --git a/drivers/staging/vme_user/vme.c b/drivers/staging/vme_user/vme.c
index b5c66b66ce32..2ed2f1fe502f 100644
--- a/drivers/staging/vme_user/vme.c
+++ b/drivers/staging/vme_user/vme.c
@@ -82,6 +82,9 @@ void *vme_alloc_consistent(struct vme_resource *resource, size_t size,
{
struct vme_bridge *bridge = find_bridge(resource);
+ if (!bridge)
+ return NULL;
+
if (!bridge->alloc_consistent) {
dev_err(bridge->parent,
"alloc_consistent not supported by bridge %s\n",
@@ -107,6 +110,9 @@ void vme_free_consistent(struct vme_resource *resource, size_t size,
{
struct vme_bridge *bridge = find_bridge(resource);
+ if (!bridge)
+ return;
+
if (!bridge->free_consistent) {
dev_err(bridge->parent,
"free_consistent not supported by bridge %s\n",
@@ -136,6 +142,9 @@ size_t vme_get_size(struct vme_resource *resource)
dma_addr_t buf_base;
u32 aspace, cycle, dwidth;
+ if (!bridge)
+ return 0;
+
switch (resource->type) {
case VME_MASTER:
retval = vme_master_get(resource, &enabled, &base, &size,
@@ -332,6 +341,9 @@ int vme_slave_set(struct vme_resource *resource, int enabled,
struct vme_slave_resource *image;
int retval;
+ if (!bridge)
+ return 0;
+
if (resource->type != VME_SLAVE) {
dev_err(bridge->parent, "Not a slave resource\n");
return -EINVAL;
@@ -381,6 +393,9 @@ int vme_slave_get(struct vme_resource *resource, int *enabled,
struct vme_bridge *bridge = find_bridge(resource);
struct vme_slave_resource *image;
+ if (!bridge)
+ return 0;
+
if (resource->type != VME_SLAVE) {
dev_err(bridge->parent, "Not a slave resource\n");
return -EINVAL;
@@ -409,6 +424,9 @@ void vme_slave_free(struct vme_resource *resource)
struct vme_bridge *bridge = find_bridge(resource);
struct vme_slave_resource *slave_image;
+ if (!bridge)
+ return;
+
if (resource->type != VME_SLAVE) {
dev_err(bridge->parent, "Not a slave resource\n");
return;
@@ -529,6 +547,9 @@ int vme_master_set(struct vme_resource *resource, int enabled,
struct vme_master_resource *image;
int retval;
+ if (!bridge)
+ return 0;
+
if (resource->type != VME_MASTER) {
dev_err(bridge->parent, "Not a master resource\n");
return -EINVAL;
@@ -579,6 +600,9 @@ int vme_master_get(struct vme_resource *resource, int *enabled,
struct vme_bridge *bridge = find_bridge(resource);
struct vme_master_resource *image;
+ if (!bridge)
+ return 0;
+
if (resource->type != VME_MASTER) {
dev_err(bridge->parent, "Not a master resource\n");
return -EINVAL;
@@ -618,6 +642,9 @@ ssize_t vme_master_read(struct vme_resource *resource, void *buf, size_t count,
struct vme_master_resource *image;
size_t length;
+ if (!bridge)
+ return 0;
+
if (!bridge->master_read) {
dev_warn(bridge->parent,
"Reading from resource not supported\n");
@@ -667,6 +694,9 @@ ssize_t vme_master_write(struct vme_resource *resource, void *buf,
struct vme_master_resource *image;
size_t length;
+ if (!bridge)
+ return 0;
+
if (!bridge->master_write) {
dev_warn(bridge->parent, "Writing to resource not supported\n");
return -EINVAL;
@@ -718,6 +748,9 @@ unsigned int vme_master_rmw(struct vme_resource *resource, unsigned int mask,
struct vme_bridge *bridge = find_bridge(resource);
struct vme_master_resource *image;
+ if (!bridge)
+ return 0;
+
if (!bridge->master_rmw) {
dev_warn(bridge->parent, "Writing to resource not supported\n");
return -EINVAL;
@@ -753,6 +786,9 @@ int vme_master_mmap_prepare(struct vme_resource *resource,
struct vme_master_resource *image;
phys_addr_t phys_addr;
+ if (!bridge)
+ return 0;
+
if (resource->type != VME_MASTER) {
dev_err(bridge->parent, "Not a master resource\n");
return -EINVAL;
@@ -783,6 +819,9 @@ void vme_master_free(struct vme_resource *resource)
struct vme_bridge *bridge = find_bridge(resource);
struct vme_master_resource *master_image;
+ if (!bridge)
+ return;
+
if (resource->type != VME_MASTER) {
dev_err(bridge->parent, "Not a master resource\n");
return;
@@ -889,6 +928,9 @@ struct vme_dma_list *vme_new_dma_list(struct vme_resource *resource)
struct vme_bridge *bridge = find_bridge(resource);
struct vme_dma_list *dma_list;
+ if (!bridge)
+ return NULL;
+
if (resource->type != VME_DMA) {
dev_err(bridge->parent, "Not a DMA resource\n");
return NULL;
@@ -1173,6 +1215,9 @@ int vme_dma_free(struct vme_resource *resource)
struct vme_bridge *bridge = find_bridge(resource);
struct vme_dma_resource *ctrlr;
+ if (!bridge)
+ return 0;
+
if (resource->type != VME_DMA) {
dev_err(bridge->parent, "Not a DMA resource\n");
return -EINVAL;
@@ -1494,6 +1539,9 @@ int vme_lm_count(struct vme_resource *resource)
struct vme_bridge *bridge = find_bridge(resource);
struct vme_lm_resource *lm;
+ if (!bridge)
+ return 0;
+
if (resource->type != VME_LM) {
dev_err(bridge->parent, "Not a Location Monitor resource\n");
return -EINVAL;
@@ -1525,6 +1573,9 @@ int vme_lm_set(struct vme_resource *resource, unsigned long long lm_base,
struct vme_bridge *bridge = find_bridge(resource);
struct vme_lm_resource *lm;
+ if (!bridge)
+ return 0;
+
if (resource->type != VME_LM) {
dev_err(bridge->parent, "Not a Location Monitor resource\n");
return -EINVAL;
@@ -1561,6 +1612,9 @@ int vme_lm_get(struct vme_resource *resource, unsigned long long *lm_base,
struct vme_bridge *bridge = find_bridge(resource);
struct vme_lm_resource *lm;
+ if (!bridge)
+ return 0;
+
if (resource->type != VME_LM) {
dev_err(bridge->parent, "Not a Location Monitor resource\n");
return -EINVAL;
@@ -1598,6 +1652,9 @@ int vme_lm_attach(struct vme_resource *resource, int monitor,
struct vme_bridge *bridge = find_bridge(resource);
struct vme_lm_resource *lm;
+ if (!bridge)
+ return 0;
+
if (resource->type != VME_LM) {
dev_err(bridge->parent, "Not a Location Monitor resource\n");
return -EINVAL;
@@ -1631,6 +1688,9 @@ int vme_lm_detach(struct vme_resource *resource, int monitor)
struct vme_bridge *bridge = find_bridge(resource);
struct vme_lm_resource *lm;
+ if (!bridge)
+ return 0;
+
if (resource->type != VME_LM) {
dev_err(bridge->parent, "Not a Location Monitor resource\n");
return -EINVAL;
@@ -1664,6 +1724,9 @@ void vme_lm_free(struct vme_resource *resource)
struct vme_bridge *bridge = find_bridge(resource);
struct vme_lm_resource *lm;
+ if (!bridge)
+ return;
+
if (resource->type != VME_LM) {
dev_err(bridge->parent, "Not a Location Monitor resource\n");
return;
--
2.43.0
next reply other threads:[~2026-05-05 20:58 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-05 20:57 Shyam Sunder Reddy Padira [this message]
2026-05-11 7:46 ` [PATCH] staging: vme_user: check find_bridge() return value Greg KH
2026-05-11 16:54 ` Shyam Sunder Reddy Padira
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