4.15-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
commit da17c73b6eb74aad3c3c0654394635675b623b3e upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/netfilter/x_tables.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -209,6 +209,9 @@ xt_request_find_match(uint8_t nfproto, c { 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 { 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);