| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 27/53] af_key: fix buffer overread in parse_exthdrs() | Date | Mon, 22 Jan 2018 09:40:19 +0100 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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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;
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