This is a note to let you know that I've just added the patch titled
af_key: fix buffer overread in verify_address_len()
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
af_key-fix-buffer-overread-in-verify_address_len.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 06b335cb51af018d5feeff5dd4fd53847ddb675a Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@xxxxxxxxxx>
Date: Fri, 29 Dec 2017 18:13:05 -0600
Subject: af_key: fix buffer overread in verify_address_len()
From: Eric Biggers <ebiggers@xxxxxxxxxx>
commit 06b335cb51af018d5feeff5dd4fd53847ddb675a upstream.
If a message sent to a PF_KEY socket ended with one of the extensions
that takes a 'struct sadb_address' but there were not enough bytes
remaining in the message for the ->sa_family member of the 'struct
sockaddr' which is supposed to follow, then verify_address_len() read
past the end of the message, into uninitialized memory. Fix it by
returning -EINVAL in this case.
This bug was found using syzkaller with KMSAN.
Reproducer:
#include <linux/pfkeyv2.h>
#include <sys/socket.h>
#include <unistd.h>
int main()
{
int sock = socket(PF_KEY, SOCK_RAW, PF_KEY_V2);
char buf[24] = { 0 };
struct sadb_msg *msg = (void *)buf;
struct sadb_address *addr = (void *)(msg + 1);
msg->sadb_msg_version = PF_KEY_V2;
msg->sadb_msg_type = SADB_DELETE;
msg->sadb_msg_len = 3;
addr->sadb_address_len = 1;
addr->sadb_address_exttype = SADB_EXT_ADDRESS_SRC;
write(sock, buf, 24);
}
Reported-by: Alexander Potapenko <glider@xxxxxxxxxx>
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/key/af_key.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -401,6 +401,11 @@ static int verify_address_len(const void
#endif
int len;
+ if (sp->sadb_address_len <
+ DIV_ROUND_UP(sizeof(*sp) + offsetofend(typeof(*addr), sa_family),
+ sizeof(uint64_t)))
+ return -EINVAL;
+
switch (addr->sa_family) {
case AF_INET:
len = DIV_ROUND_UP(sizeof(*sp) + sizeof(*sin), sizeof(uint64_t));
Patches currently in stable-queue which might be from ebiggers@xxxxxxxxxx are
queue-3.18/af_key-fix-buffer-overread-in-parse_exthdrs.patch
queue-3.18/af_key-fix-buffer-overread-in-verify_address_len.patch