6.12-stable review patch. If anyone has any objections, please let me know.
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From: Matt Johnston matt@codeconstruct.com.au
[ 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@codeconstruct.com.au Fixes: c8755b29b58e ("mctp i3c: MCTP I3C driver") Link: https://patch.msgid.link/20250306-matt-i3c-cow-head-v1-1-d5e6a5495227@codeco... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 a2b15cddf46e6..47513ebbc6807 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);