generic: fix kernel panic on existing mac-address node

Calling free for the OF property can result in a kernel panic, as the
buffer in question might be referenced elsewhere. Also, it is not
removed from the tree.

Always allocate a new property and updating the tree with it fixes both
issues.

Fixes commit 91a52f22a1 ("treewide: backport support for nvmem on non platform devices")

Signed-off-by: David Bauer <mail@david-bauer.net>
This commit is contained in:
David Bauer 2021-08-10 00:28:01 +02:00
parent 5ecd99f7d2
commit 29a3967e61
2 changed files with 8 additions and 16 deletions

View File

@ -1,6 +1,6 @@
--- a/drivers/of/of_net.c
+++ b/drivers/of/of_net.c
@@ -141,6 +141,30 @@ static int of_get_mac_address_mtd(struct
@@ -135,6 +135,26 @@ static int of_get_mac_address_mtd(struct
return -EINVAL;
}
@ -8,18 +8,14 @@
+{
+ struct property *prop;
+
+ prop = of_find_property(np, "mac-address", NULL);
+ if (prop)
+ kfree(prop);
+
+ prop = kzalloc(sizeof(*prop), GFP_KERNEL);
+ if (!prop)
+ return 0;
+ return -ENOMEM;
+
+ prop->name = "mac-address";
+ prop->length = ETH_ALEN;
+ prop->value = kmemdup(addr, ETH_ALEN, GFP_KERNEL);
+ if (!prop->value || of_add_property(np, prop))
+ if (!prop->value || of_update_property(np, prop))
+ goto free;
+
+ return 0;
@ -31,7 +27,7 @@
/**
* Search the device tree for the best MAC address to use. 'mac-address' is
@@ -216,6 +240,7 @@ found:
@@ -210,6 +230,7 @@ found:
if (!of_property_read_u32(np, "mac-address-increment", &mac_inc))
addr[inc_idx] += mac_inc;

View File

@ -1,6 +1,6 @@
--- a/drivers/of/of_net.c
+++ b/drivers/of/of_net.c
@@ -135,6 +135,30 @@ static int of_get_mac_address_mtd(struct
@@ -135,6 +135,26 @@ static int of_get_mac_address_mtd(struct
return -EINVAL;
}
@ -8,18 +8,14 @@
+{
+ struct property *prop;
+
+ prop = of_find_property(np, "mac-address", NULL);
+ if (prop)
+ kfree(prop);
+
+ prop = kzalloc(sizeof(*prop), GFP_KERNEL);
+ if (!prop)
+ return 0;
+ return -ENOMEM;
+
+ prop->name = "mac-address";
+ prop->length = ETH_ALEN;
+ prop->value = kmemdup(addr, ETH_ALEN, GFP_KERNEL);
+ if (!prop->value || of_add_property(np, prop))
+ if (!prop->value || of_update_property(np, prop))
+ goto free;
+
+ return 0;
@ -31,7 +27,7 @@
/**
* Search the device tree for the best MAC address to use. 'mac-address' is
@@ -210,6 +234,7 @@ found:
@@ -210,6 +230,7 @@ found:
if (!of_property_read_u32(np, "mac-address-increment", &mac_inc))
addr[inc_idx] += mac_inc;