Commit df8ce77b authored by Matt Johnston's avatar Matt Johnston Committed by Jakub Kicinski
Browse files

net: mctp i2c: Copy headers if cloned 



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: default avatarMatt Johnston <matt@codeconstruct.com.au>
Fixes: f5b8abf9 ("mctp i2c: MCTP I2C binding driver")
Link: https://patch.msgid.link/20250306-matt-mctp-i2c-cow-v1-1-293827212681@codeconstruct.com.au


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 26db9c9e

drivers/net/mctp/mctp-i2c.c

+5 −0
Original line number Diff line number Diff line
@@ -583,6 +583,7 @@ static int mctp_i2c_header_create(struct sk_buff *skb, struct net_device *dev, 
	struct mctp_i2c_hdr *hdr;

	struct mctp_hdr *mhdr;

	u8 lldst, llsrc;

	int rc;



	if (len > MCTP_I2C_MAXMTU)

		return -EMSGSIZE;
@@ -593,6 +594,10 @@ static int mctp_i2c_header_create(struct sk_buff *skb, struct net_device *dev, 
	lldst = *((u8 *)daddr);

	llsrc = *((u8 *)saddr);



	rc = skb_cow_head(skb, sizeof(struct mctp_i2c_hdr));

	if (rc)

		return rc;



	skb_push(skb, sizeof(struct mctp_i2c_hdr));

	skb_reset_mac_header(skb);

	hdr = (void *)skb_mac_header(skb);