netfilter: x_tables: avoid out-of-bounds reads in xt_request_find_{match|target} (da17c73b) · Commits · 戴 / test

It looks like syzbot found its way into netfilter territory. Issue here is that @name comes from user space and might not be null terminated. Out-of-bound reads happen, KASAN is not happy. v2 added similar fix for xt_request_find_target(), as Florian advised. Signed-off-by:

Eric Dumazet <edumazet@google.com> Reported-by:

syzbot <syzkaller@googlegroups.com> Acked-by:

Florian Westphal <fw@strlen.de> Signed-off-by:

Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/x_tables.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -209,6 +209,9 @@ xt_request_find_match(uint8_t nfproto, const char *name, uint8_t revision)
		{
		struct xt_match *match;

		if (strnlen(name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN)
		return ERR_PTR(-EINVAL);

		match = xt_find_match(nfproto, name, revision);
		if (IS_ERR(match)) {
		request_module("%st_%s", xt_prefix[nfproto], name);
		@@ -251,6 +254,9 @@ struct xt_target xt_request_find_target(u8 af, const char name, u8 revision)
		{
		struct xt_target *target;

		if (strnlen(name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN)
		return ERR_PTR(-EINVAL);

		target = xt_find_target(af, name, revision);
		if (IS_ERR(target)) {
		request_module("%st_%s", xt_prefix[af], name);

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