This is a note to let you know that I've just added the patch titled

af_key: fix buffer overread in parse_exthdrs()

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: af_key-fix-buffer-overread-in-parse_exthdrs.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 4e765b4972af7b07adcb1feb16e7a525ce1f6b28 Mon Sep 17 00:00:00 2001

From: Eric Biggers ebiggers@google.com Date: Fri, 29 Dec 2017 18:15:23 -0600 Subject: af_key: fix buffer overread in parse_exthdrs()

From: Eric Biggers ebiggers@google.com

commit 4e765b4972af7b07adcb1feb16e7a525ce1f6b28 upstream.

If a message sent to a PF_KEY socket ended with an incomplete extension header (fewer than 4 bytes remaining), then parse_exthdrs() read past the end of the message, into uninitialized memory. Fix it by returning -EINVAL in this case.

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[17] = { 0 }; struct sadb_msg *msg = (void *)buf;

msg->sadb_msg_version = PF_KEY_V2; msg->sadb_msg_type = SADB_DELETE; msg->sadb_msg_len = 2;

write(sock, buf, 17); }

Signed-off-by: Eric Biggers ebiggers@google.com Signed-off-by: Steffen Klassert steffen.klassert@secunet.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- net/key/af_key.c | 3 +++ 1 file changed, 3 insertions(+)

--- a/net/key/af_key.c +++ b/net/key/af_key.c @@ -516,6 +516,9 @@ static int parse_exthdrs(struct sk_buff uint16_t ext_type; int ext_len;

+ if (len < sizeof(*ehdr)) + return -EINVAL; + ext_len = ehdr->sadb_ext_len; ext_len *= sizeof(uint64_t); ext_type = ehdr->sadb_ext_type;

Patches currently in stable-queue which might be from ebiggers@google.com are

queue-4.9/af_key-fix-buffer-overread-in-parse_exthdrs.patch queue-4.9/af_key-fix-buffer-overread-in-verify_address_len.patch