From 4958b0bf1221bdf3f7e30ff0fd235eb6321d5efb Mon Sep 17 00:00:00 2001 From: Jeremy Sowden Date: Tue, 30 Nov 2021 10:55:38 +0000 Subject: input: UNIXSOCK: prevent unaligned pointer access `struct ulogd_unixsock_packet_t` is packed, so taking the address of its `struct iphdr payload` member may yield an unaligned pointer value. We only actually dereference the pointer to get the IP version, so replace the pointer with a version variable and elsewhere use `pkt.payload` directly. Remove a couple of stray semicolons. Signed-off-by: Jeremy Sowden Signed-off-by: Pablo Neira Ayuso --- input/packet/ulogd_inppkt_UNIXSOCK.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'input') diff --git a/input/packet/ulogd_inppkt_UNIXSOCK.c b/input/packet/ulogd_inppkt_UNIXSOCK.c index 0080c6a..f1d1534 100644 --- a/input/packet/ulogd_inppkt_UNIXSOCK.c +++ b/input/packet/ulogd_inppkt_UNIXSOCK.c @@ -371,7 +371,7 @@ struct ulogd_unixsock_option_t { static int handle_packet(struct ulogd_pluginstance *upi, struct ulogd_unixsock_packet_t *pkt, uint16_t total_len) { char *data = NULL; - struct iphdr *ip; + unsigned int ip_version = pkt->payload.version; struct ulogd_key *ret = upi->output.keys; uint8_t oob_family; uint16_t payload_len; @@ -387,22 +387,22 @@ static int handle_packet(struct ulogd_pluginstance *upi, struct ulogd_unixsock_p payload_len = ntohs(pkt->payload_length); - ip = &pkt->payload; - if (ip->version == 4) + if (ip_version == 4) oob_family = AF_INET; - else if (ip->version == 6) + else if (ip_version == 6) oob_family = AF_INET6; - else oob_family = 0; + else + oob_family = 0; okey_set_u8(&ret[UNIXSOCK_KEY_OOB_FAMILY], oob_family); - okey_set_ptr(&ret[UNIXSOCK_KEY_RAW_PCKT], ip); + okey_set_ptr(&ret[UNIXSOCK_KEY_RAW_PCKT], &pkt->payload); okey_set_u32(&ret[UNIXSOCK_KEY_RAW_PCKTLEN], payload_len); /* options */ if (total_len > payload_len + sizeof(uint16_t)) { /* option starts at the next aligned address after the payload */ new_offset = USOCK_ALIGN(payload_len); - options_start = (void*)ip + new_offset; + options_start = (void*)&pkt->payload + new_offset; data = options_start; total_len -= (options_start - (char*)pkt); @@ -460,7 +460,7 @@ static int handle_packet(struct ulogd_pluginstance *upi, struct ulogd_unixsock_p "ulogd2: unknown option %d\n", option_number); break; - }; + } } } @@ -666,7 +666,7 @@ static int unixsock_instance_read_cb(int fd, unsigned int what, void *param) } /* handle_packet has shifted data in buffer */ - }; + } return 0; } -- cgit v1.2.3