From b7ea5ae197085e2b985b86cb29f47b44e4e9f578 Mon Sep 17 00:00:00 2001 From: Jack He Date: Fri, 1 Jun 2018 14:00:42 -0700 Subject: BNEP: Fix OOB access in bnep_data_ind * Stop reading the L2CAP packet if packet length is 0 * Process the buffer for BNEP_EXTENSION_CONTROL packet before advancing the buffer pointer by length of payload * Reject BNEP_EXTENSION_CONTROL packet when the payload size is zero * Move error logging to more appropriate locations at where the OOB access is most likely triggered Bug: 78286118 Bug: 79164722 Test: Send zero length L2CAP packet to BNEP, send invalid BNEP_EXTENSION_CONTROL packet Merged-In: I7e18632b8faab1b6aaca1bff1b7f55d69962729e Change-Id: I7e18632b8faab1b6aaca1bff1b7f55d69962729e (cherry picked from commit 3c799a6e25abdf6bacb660ff7a06338836cc7356) (cherry picked from commit 0416340ffa61337dbaa2f6602ef85a1c32563ec2) --- stack/bnep/bnep_main.c | 35 ++++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 9 deletions(-) diff --git a/stack/bnep/bnep_main.c b/stack/bnep/bnep_main.c index cb7a3c20d..0fb3e0e2f 100644 --- a/stack/bnep/bnep_main.c +++ b/stack/bnep/bnep_main.c @@ -468,6 +468,11 @@ static void bnep_data_ind (UINT16 l2cap_cid, BT_HDR *p_buf) tBNEP_CONN *p_bcb; UINT8 *p = (UINT8 *)(p_buf + 1) + p_buf->offset; UINT16 rem_len = p_buf->len; + if (rem_len == 0) { + android_errorWriteLog(0x534e4554, "78286118"); + osi_free(p_buf); + return; + } UINT8 type, ctrl_type, ext_type = 0; BOOLEAN extension_present, fw_ext_present; UINT16 protocol = 0; @@ -520,22 +525,34 @@ static void bnep_data_ind (UINT16 l2cap_cid, BT_HDR *p_buf) UINT16 org_len, new_len; /* parse the extension headers and process unknown control headers */ org_len = rem_len; - new_len = 0; do { - if (org_len < 2) break; + if (org_len < 2) { + android_errorWriteLog(0x534e4554, "67863755"); + break; + } ext = *p++; length = *p++; - p += length; new_len = (length + 2); - if (new_len > org_len) break; + if (new_len > org_len) { + android_errorWriteLog(0x534e4554, "67863755"); + break; + } + + if ((ext & 0x7F) == BNEP_EXTENSION_FILTER_CONTROL) { + if (length == 0) { + android_errorWriteLog(0x534e4554, "79164722"); + break; + } + if (*p > BNEP_FILTER_MULTI_ADDR_RESPONSE_MSG) { + bnep_send_command_not_understood(p_bcb, *p); + } + } - if ((!(ext & 0x7F)) && (*p > BNEP_FILTER_MULTI_ADDR_RESPONSE_MSG)) - bnep_send_command_not_understood (p_bcb, *p); + p += length; org_len -= new_len; } while (ext & 0x80); - android_errorWriteLog(0x534e4554, "67863755"); } GKI_freebuf (p_buf); @@ -589,14 +606,14 @@ static void bnep_data_ind (UINT16 l2cap_cid, BT_HDR *p_buf) { ext_type = *p++; rem_len--; - android_errorWriteLog(0x534e4554, "69271284"); extension_present = ext_type >> 7; ext_type &= 0x7F; /* if unknown extension present stop processing */ - if (ext_type) + if (ext_type != BNEP_EXTENSION_FILTER_CONTROL) break; + android_errorWriteLog(0x534e4554, "69271284"); p = bnep_process_control_packet (p_bcb, p, &rem_len, TRUE); } } -- cgit v1.2.3