diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2026-05-22 16:06:42 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-05-26 08:17:56 -0700 |
| commit | c75b6f6eaacd0b74b832414cc3b9289c3686e941 (patch) | |
| tree | 149558b220a3fe5cf3c2c1684c188f9ae526757f /net/ethtool | |
| parent | 2e357f002c61fd76fd8f12468744a06a5ec48eaa (diff) | |
ethtool: rss: avoid modifying the RSS context response
Gemini says that we're modifying the RSS_CREATE response skb.
I think it's right, the comment says that unicast() should
unshare the skb but I'm not entirely sure what I meant there.
netlink_trim() does a copy but only if skb is not well sized
(it's at least 2x larger than necessary for the payload).
Fixes: a166ab7816c5 ("ethtool: rss: support creating contexts via Netlink")
Link: https://patch.msgid.link/20260522230647.1705600-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ethtool')
| -rw-r--r-- | net/ethtool/rss.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/net/ethtool/rss.c b/net/ethtool/rss.c index 353110b862ab..8ffec9785efa 100644 --- a/net/ethtool/rss.c +++ b/net/ethtool/rss.c @@ -981,11 +981,17 @@ ethnl_rss_create_validate(struct net_device *dev, struct genl_info *info) } static void -ethnl_rss_create_send_ntf(struct sk_buff *rsp, struct net_device *dev) +ethnl_rss_create_send_ntf(const struct sk_buff *rsp, struct net_device *dev) { - struct nlmsghdr *nlh = (void *)rsp->data; struct genlmsghdr *genl_hdr; + struct nlmsghdr *nlh; + struct sk_buff *ntf; + + ntf = skb_copy_expand(rsp, 0, 0, GFP_KERNEL); + if (!ntf) + return; + nlh = nlmsg_hdr(ntf); /* Convert the reply into a notification */ nlh->nlmsg_pid = 0; nlh->nlmsg_seq = ethnl_bcast_seq_next(); @@ -993,7 +999,7 @@ ethnl_rss_create_send_ntf(struct sk_buff *rsp, struct net_device *dev) genl_hdr = nlmsg_data(nlh); genl_hdr->cmd = ETHTOOL_MSG_RSS_CREATE_NTF; - ethnl_multicast(rsp, dev); + ethnl_multicast(ntf, dev); } int ethnl_rss_create_doit(struct sk_buff *skb, struct genl_info *info) @@ -1104,12 +1110,8 @@ int ethnl_rss_create_doit(struct sk_buff *skb, struct genl_info *info) genlmsg_end(rsp, hdr); - /* Use the same skb for the response and the notification, - * genlmsg_reply() will copy the skb if it has elevated user count. - */ - skb_get(rsp); - ret = genlmsg_reply(rsp, info); ethnl_rss_create_send_ntf(rsp, dev); + ret = genlmsg_reply(rsp, info); rsp = NULL; exit_unlock: |