Commit a9687605 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

netlink: fix policy dump for int with validation callback 



Recent devlink change added validation of an integer value
via NLA_POLICY_VALIDATE_FN, for sparse enums. Handle this
in policy dump. We can't extract any info out of the callback,
so report only the type.

Fixes: 429ac621 ("devlink: define enum for attr types of dynamic attributes")
Reported-by: default avatar <syzbot+01eb26848144516e7f0a@syzkaller.appspotmail.com>
Link: https://patch.msgid.link/20250509212751.1905149-1-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent cc422631

include/net/netlink.h

+6 −0
Original line number Diff line number Diff line
@@ -321,7 +321,13 @@ enum nla_policy_validation { 
 *    All other            Unused - but note that it's a union

 *

 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:

 *    NLA_U8, NLA_U16,

 *    NLA_U32, NLA_U64,

 *    NLA_S8, NLA_S16,

 *    NLA_S32, NLA_S64,

 *    NLA_MSECS,

 *    NLA_BINARY           Validation function called for the attribute.

 *

 *    All other            Unused - but note that it's a union

 *

 * Example:

net/netlink/policy.c

+5 −0
Original line number Diff line number Diff line
@@ -311,6 +311,8 @@ __netlink_policy_dump_write_attr(struct netlink_policy_dump_state *state, 
					      NL_POLICY_TYPE_ATTR_PAD))

				goto nla_put_failure;

			break;

		} else if (pt->validation_type == NLA_VALIDATE_FUNCTION) {

			break;

		}



		nla_get_range_unsigned(pt, &range);
@@ -340,6 +342,9 @@ __netlink_policy_dump_write_attr(struct netlink_policy_dump_state *state, 
		else

			type = NL_ATTR_TYPE_SINT;



		if (pt->validation_type == NLA_VALIDATE_FUNCTION)

			break;



		nla_get_range_signed(pt, &range);



		if (nla_put_s64(skb, NL_POLICY_TYPE_ATTR_MIN_VALUE_S,