Commit c30a3c95 authored Aug 31, 2020 by Johannes Berg Committed by David S. Miller Aug 31, 2020

netlink: policy: correct validation type check



In the policy export for binary attributes I erroneously used
a != NLA_VALIDATE_NONE comparison instead of checking for the
two possible values, which meant that if a validation function
pointer ended up aliasing the min/max as negatives, we'd hit
a warning in nla_get_range_unsigned().

Fix this to correctly check for only the two types that should
be handled here, i.e. range with or without warn-too-long.

Reported-by:  <syzbot+353df1490da781637624@syzkaller.appspotmail.com>
Fixes: 8aa26c57 ("netlink: make NLA_BINARY validation more flexible")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 0f091e43

net/netlink/policy.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -264,7 +264,8 @@ send_attribute:
		else
		type = NL_ATTR_TYPE_BINARY;

		if (pt->validation_type != NLA_VALIDATE_NONE) {
		if (pt->validation_type == NLA_VALIDATE_RANGE \|\|
		pt->validation_type == NLA_VALIDATE_RANGE_WARN_TOO_LONG) {
		struct netlink_range_validation range;

		nla_get_range_unsigned(pt, &range);

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