kernel: fix bugs added with mac-address-ascii support

1. Check for -EPROBE_DEFER
If it occurs we have to return immediately. Trying other properties
could result in another error and ignoring -EPROBE_DEFER which has a
special meaning.

2. Check for read result
Assuming property->read() success can result in NULL pointer
dereference. It happens e.g. for "mac-address" with NVMEM cell
containing invalid MAC.

3. Simplify code
Don't move cell reading & nvmem_cell_put() into a loop. Simplify loop
code.

Fixes: ecd81de7a5 ("ath79: add nvmem cell mac-address-ascii support")
Cc: Yousong Zhou <yszhou4tech@gmail.com>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
This commit is contained in:
Rafał Miłecki 2023-01-05 13:33:18 +01:00
parent 7c574525ee
commit a1abf71827
2 changed files with 38 additions and 40 deletions

View File

@ -75,36 +75,35 @@ Submitted-by: Yousong Zhou <yszhou4tech@gmail.com>
/**
* Obtain the MAC address from an nvmem cell named 'mac-address' associated
* with given device.
@@ -552,19 +609,23 @@ int nvmem_get_mac_address(struct device
@@ -550,21 +607,28 @@ EXPORT_SYMBOL(eth_platform_get_mac_addre
*/
int nvmem_get_mac_address(struct device *dev, void *addrbuf)
{
+ struct nvmem_cell_mac_address_property *property;
struct nvmem_cell *cell;
const void *mac;
- size_t len;
+ struct nvmem_cell_mac_address_property *property;
+ int i;
- cell = nvmem_cell_get(dev, "mac-address");
- if (IS_ERR(cell))
- return PTR_ERR(cell);
-
- mac = nvmem_cell_read(cell, &len);
- nvmem_cell_put(cell);
-
- if (IS_ERR(mac))
- return PTR_ERR(mac);
+
+ for (i = 0; i < ARRAY_SIZE(nvmem_cell_mac_address_properties); i++) {
+ property = &nvmem_cell_mac_address_properties[i];
+ cell = nvmem_cell_get(dev, property->name);
+ if (IS_ERR(cell)) {
+ if (i == ARRAY_SIZE(nvmem_cell_mac_address_properties) - 1)
+ return PTR_ERR(cell);
+ continue;
+ }
+ mac = property->read(cell);
+ nvmem_cell_put(cell);
+ break;
+ /* For -EPROBE_DEFER don't try other properties. We'll get back to this one. */
+ if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER)
+ break;
+ }
- cell = nvmem_cell_get(dev, "mac-address");
if (IS_ERR(cell))
return PTR_ERR(cell);
- mac = nvmem_cell_read(cell, &len);
+ mac = property->read(cell);
nvmem_cell_put(cell);
-
if (IS_ERR(mac))
return PTR_ERR(mac);
- if (len != ETH_ALEN || !is_valid_ether_addr(mac)) {
+ if (!is_valid_ether_addr(mac)) {
kfree(mac);

View File

@ -75,36 +75,35 @@ Submitted-by: Yousong Zhou <yszhou4tech@gmail.com>
/**
* nvmem_get_mac_address - Obtain the MAC address from an nvmem cell named
* 'mac-address' associated with given device.
@@ -551,19 +608,23 @@ int nvmem_get_mac_address(struct device
@@ -549,21 +606,28 @@ EXPORT_SYMBOL(eth_platform_get_mac_addre
*/
int nvmem_get_mac_address(struct device *dev, void *addrbuf)
{
+ struct nvmem_cell_mac_address_property *property;
struct nvmem_cell *cell;
const void *mac;
- size_t len;
+ struct nvmem_cell_mac_address_property *property;
+ int i;
- cell = nvmem_cell_get(dev, "mac-address");
- if (IS_ERR(cell))
- return PTR_ERR(cell);
-
- mac = nvmem_cell_read(cell, &len);
- nvmem_cell_put(cell);
-
- if (IS_ERR(mac))
- return PTR_ERR(mac);
+
+ for (i = 0; i < ARRAY_SIZE(nvmem_cell_mac_address_properties); i++) {
+ property = &nvmem_cell_mac_address_properties[i];
+ cell = nvmem_cell_get(dev, property->name);
+ if (IS_ERR(cell)) {
+ if (i == ARRAY_SIZE(nvmem_cell_mac_address_properties) - 1)
+ return PTR_ERR(cell);
+ continue;
+ }
+ mac = property->read(cell);
+ nvmem_cell_put(cell);
+ break;
+ /* For -EPROBE_DEFER don't try other properties. We'll get back to this one. */
+ if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER)
+ break;
+ }
- cell = nvmem_cell_get(dev, "mac-address");
if (IS_ERR(cell))
return PTR_ERR(cell);
- mac = nvmem_cell_read(cell, &len);
+ mac = property->read(cell);
nvmem_cell_put(cell);
-
if (IS_ERR(mac))
return PTR_ERR(mac);
- if (len != ETH_ALEN || !is_valid_ether_addr(mac)) {
+ if (!is_valid_ether_addr(mac)) {
kfree(mac);