From 29a3967e61334d0c6a1a7d391f0e751272d77b1d Mon Sep 17 00:00:00 2001 From: David Bauer Date: Tue, 10 Aug 2021 00:28:01 +0200 Subject: [PATCH] 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 91a52f22a13d ("treewide: backport support for nvmem on non platform devices") Signed-off-by: David Bauer --- .../683-of_net-add-mac-address-to-of-tree.patch | 12 ++++-------- .../683-of_net-add-mac-address-to-of-tree.patch | 12 ++++-------- 2 files changed, 8 insertions(+), 16 deletions(-) diff --git a/target/linux/generic/pending-5.10/683-of_net-add-mac-address-to-of-tree.patch b/target/linux/generic/pending-5.10/683-of_net-add-mac-address-to-of-tree.patch index 509d721403..ea5883f037 100644 --- a/target/linux/generic/pending-5.10/683-of_net-add-mac-address-to-of-tree.patch +++ b/target/linux/generic/pending-5.10/683-of_net-add-mac-address-to-of-tree.patch @@ -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; diff --git a/target/linux/generic/pending-5.4/683-of_net-add-mac-address-to-of-tree.patch b/target/linux/generic/pending-5.4/683-of_net-add-mac-address-to-of-tree.patch index 622d19d4ff..ea5883f037 100644 --- a/target/linux/generic/pending-5.4/683-of_net-add-mac-address-to-of-tree.patch +++ b/target/linux/generic/pending-5.4/683-of_net-add-mac-address-to-of-tree.patch @@ -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; -- 2.30.2