From: David Howells <dhowells@redhat.com>
To: syzbot <syzbot+94bbb75204a05da3d89f@syzkaller.appspotmail.com>
Cc: dhowells@redhat.com, davem@davemloft.net, edumazet@google.com,
jarkko@kernel.org, jmorris@namei.org, keyrings@vger.kernel.org,
kuba@kernel.org, linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org, netdev@vger.kernel.org,
pabeni@redhat.com, paul@paul-moore.com, serge@hallyn.com,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse
Date: Sat, 23 Dec 2023 23:34:31 +0000 [thread overview]
Message-ID: <2592301.1703374471@warthog.procyon.org.uk> (raw)
In-Reply-To: <0000000000009b39bc060c73e209@google.com>
#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
index 2a6d363763a2..f18ca02aa95a 100644
--- a/net/dns_resolver/dns_key.c
+++ b/net/dns_resolver/dns_key.c
@@ -91,8 +91,6 @@ const struct cred *dns_resolver_cache;
static int
dns_resolver_preparse(struct key_preparsed_payload *prep)
{
- const struct dns_server_list_v1_header *v1;
- const struct dns_payload_header *bin;
struct user_key_payload *upayload;
unsigned long derrno;
int ret;
@@ -103,27 +101,28 @@ dns_resolver_preparse(struct key_preparsed_payload *prep)
return -EINVAL;
if (data[0] == 0) {
+ const struct dns_server_list_v1_header *v1;
+
/* It may be a server list. */
- if (datalen <= sizeof(*bin))
+ if (datalen <= sizeof(*v1))
return -EINVAL;
- bin = (const struct dns_payload_header *)data;
- kenter("[%u,%u],%u", bin->content, bin->version, datalen);
- if (bin->content != DNS_PAYLOAD_IS_SERVER_LIST) {
+ v1 = (const struct dns_server_list_v1_header *)data;
+ kenter("[%u,%u],%u", v1->hdr.content, v1->hdr.version, datalen);
+ if (v1->hdr.content != DNS_PAYLOAD_IS_SERVER_LIST) {
pr_warn_ratelimited(
"dns_resolver: Unsupported content type (%u)\n",
- bin->content);
+ v1->hdr.content);
return -EINVAL;
}
- if (bin->version != 1) {
+ if (v1->hdr.version != 1) {
pr_warn_ratelimited(
"dns_resolver: Unsupported server list version (%u)\n",
- bin->version);
+ v1->hdr.version);
return -EINVAL;
}
- v1 = (const struct dns_server_list_v1_header *)bin;
if ((v1->status != DNS_LOOKUP_GOOD &&
v1->status != DNS_LOOKUP_GOOD_WITH_BAD)) {
if (prep->expiry == TIME64_MAX)
next prev parent reply other threads:[~2023-12-23 23:34 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-14 8:15 [syzbot] [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse syzbot
2023-12-14 14:33 ` [PATCH next] keys/dns: datalen must greater than sizeof(*v1) Edward Adam Davis
2023-12-14 14:46 ` [PATCH V2 next] keys/dns: fix slab-out-of-bounds in dns_resolver_preparse Edward Adam Davis
2023-12-16 21:06 ` Simon Horman
2023-12-15 3:00 ` [PATCH next] keys/dns: datalen must greater than sizeof(*v1) Jarkko Sakkinen
2023-12-23 23:17 ` [syzbot] [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse David Howells
2023-12-23 23:17 ` syzbot
2023-12-23 23:34 ` David Howells [this message]
2023-12-23 23:59 ` syzbot
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