ethtool: pse-pd: move pse validation into set

Move validation into set, removing .set_validate operation as its current
implementation holds the rtnl lock for acquiring the PHY device, defeating
the intended purpose of checking before grabbing the lock.

Reported-by: syzbot+ec369e6d58e210135f71@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=ec369e6d58e210135f71
Fixes: 31748765bed3 ("net: ethtool: pse-pd: Target the command to the requested PHY")
Signed-off-by: Diogo Jahchan Koike <djahchankoike@gmail.com>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20240829184830.5861-1-djahchankoike@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ethtool/pse-pd.c b/net/ethtool/pse-pd.c
index 507cb21d6bf0c5a3434d6e013a2b5481a2222f95..a0705edca22a1a6bf0adeec1efe3a7dad3a3ce6f 100644 (file)
--- a/net/ethtool/pse-pd.c
+++ b/net/ethtool/pse-pd.c
@@ -222,13 +222,10 @@ const struct nla_policy ethnl_pse_set_policy[ETHTOOL_A_PSE_MAX + 1] = {
 };
 
 static int
-ethnl_set_pse_validate(struct ethnl_req_info *req_info, struct genl_info *info)
+ethnl_set_pse_validate(struct phy_device *phydev, struct genl_info *info)
 {
        struct nlattr **tb = info->attrs;
-       struct phy_device *phydev;
 
-       phydev = ethnl_req_get_phydev(req_info, tb[ETHTOOL_A_PSE_HEADER],
-                                     info->extack);
        if (IS_ERR_OR_NULL(phydev)) {
                NL_SET_ERR_MSG(info->extack, "No PHY is attached");
                return -EOPNOTSUPP;
@@ -254,7 +251,7 @@ ethnl_set_pse_validate(struct ethnl_req_info *req_info, struct genl_info *info)
                return -EOPNOTSUPP;
        }
 
-       return 1;
+       return 0;
 }
 
 static int
@@ -262,12 +259,13 @@ ethnl_set_pse(struct ethnl_req_info *req_info, struct genl_info *info)
 {
        struct nlattr **tb = info->attrs;
        struct phy_device *phydev;
-       int ret = 0;
+       int ret;
 
        phydev = ethnl_req_get_phydev(req_info, tb[ETHTOOL_A_PSE_HEADER],
                                      info->extack);
-       if (IS_ERR_OR_NULL(phydev))
-               return -ENODEV;
+       ret = ethnl_set_pse_validate(phydev, info);
+       if (ret)
+               return ret;
 
        if (tb[ETHTOOL_A_C33_PSE_AVAIL_PW_LIMIT]) {
                unsigned int pw_limit;
@@ -314,7 +312,6 @@ const struct ethnl_request_ops ethnl_pse_request_ops = {
        .fill_reply             = pse_fill_reply,
        .cleanup_data           = pse_cleanup_data,
 
-       .set_validate           = ethnl_set_pse_validate,
        .set                    = ethnl_set_pse,
        /* PSE has no notification */
 };