From acc657692aed438e9931438f8c923b2b107aebf9 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 10 Jan 2024 21:11:40 +0000 Subject: [PATCH] keys, dns: Fix size check of V1 server-list header Fix the size check added to dns_resolver_preparse() for the V1 server-list header so that it doesn't give EINVAL if the size supplied is the same as the size of the header struct (which should be valid). This can be tested with: echo -n -e '\0\0\01\xff\0\0' | keyctl padd dns_resolver desc @p which will give "add_key: Invalid argument" without this fix. Fixes: 1997b3cb4217 ("keys, dns: Fix missing size check of V1 server-list header") Reported-by: Pengfei Xu Link: https://lore.kernel.org/r/ZZ4fyY4r3rqgZL+4@xpf.sh.intel.com/ Signed-off-by: David Howells Signed-off-by: Linus Torvalds --- net/dns_resolver/dns_key.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c index f18ca02aa95a..c42ddd85ff1f 100644 --- a/net/dns_resolver/dns_key.c +++ b/net/dns_resolver/dns_key.c @@ -104,7 +104,7 @@ dns_resolver_preparse(struct key_preparsed_payload *prep) const struct dns_server_list_v1_header *v1; /* It may be a server list. */ - if (datalen <= sizeof(*v1)) + if (datalen < sizeof(*v1)) return -EINVAL; v1 = (const struct dns_server_list_v1_header *)data;