6.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: Matt Johnston <matt@xxxxxxxxxxxxxxxxxxxx>
[ Upstream commit 26db9c9ee19c36a97dbb1cfef007a3c189c4c874 ]
Use skb_cow_head() prior to modifying the tx skb. This is necessary
when the skb has been cloned, to avoid modifying other shared clones.
Signed-off-by: Matt Johnston <matt@xxxxxxxxxxxxxxxxxxxx>
Fixes: c8755b29b58e ("mctp i3c: MCTP I3C driver")
Link: https://patch.msgid.link/20250306-matt-i3c-cow-head-v1-1-d5e6a5495227@xxxxxxxxxxxxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/mctp/mctp-i3c.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/net/mctp/mctp-i3c.c b/drivers/net/mctp/mctp-i3c.c
index c1e72253063b5..c678f79aa3561 100644
--- a/drivers/net/mctp/mctp-i3c.c
+++ b/drivers/net/mctp/mctp-i3c.c
@@ -506,10 +506,15 @@ static int mctp_i3c_header_create(struct sk_buff *skb, struct net_device *dev,
const void *saddr, unsigned int len)
{
struct mctp_i3c_internal_hdr *ihdr;
+ int rc;
if (!daddr || !saddr)
return -EINVAL;
+ rc = skb_cow_head(skb, sizeof(struct mctp_i3c_internal_hdr));
+ if (rc)
+ return rc;
+
skb_push(skb, sizeof(struct mctp_i3c_internal_hdr));
skb_reset_mac_header(skb);
ihdr = (void *)skb_mac_header(skb);
--
2.39.5
