Commit 1894e893 authored by Ben Hutchings's avatar Ben Hutchings

mwifiex: Don't abort on small, spec-compliant vendor IEs

parent 70b1e1a8
......@@ -11,6 +11,7 @@ linux (4.19.37-4) UNRELEASED; urgency=medium
* mwifiex: Fix possible buffer overflows at parsing bss descriptor
(CVE-2019-3846)
* mwifiex: Abort at too short BSS descriptor element
* mwifiex: Don't abort on small, spec-compliant vendor IEs
[ Romain Perier ]
* [rt] Update to 4.19.37-rt20
......
From: Brian Norris <briannorris@chromium.org>
Subject: [PATCH 5.2 1/2] mwifiex: Don't abort on small,
spec-compliant vendor IEs
Date: Fri, 14 Jun 2019 17:13:20 -0700
Origin: https://patchwork.kernel.org/patch/10996895/
Per the 802.11 specification, vendor IEs are (at minimum) only required
to contain an OUI. A type field is also included in ieee80211.h (struct
ieee80211_vendor_ie) but doesn't appear in the specification. The
remaining fields (subtype, version) are a convention used in WMM
headers.
Thus, we should not reject vendor-specific IEs that have only the
minimum length (3 bytes) -- we should skip over them (since we only want
to match longer IEs, that match either WMM or WPA formats). We can
reject elements that don't have the minimum-required 3 byte OUI.
While we're at it, move the non-standard subtype and version fields into
the WMM structs, to avoid this confusion in the future about generic
"vendor header" attributes.
Fixes: 685c9b7750bf ("mwifiex: Abort at too short BSS descriptor element")
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Brian Norris <briannorris@chromium.org>
---
It appears that commit 685c9b7750bf is on its way to 5.2, so I labeled
this bugfix for 5.2 as well.
drivers/net/wireless/marvell/mwifiex/fw.h | 12 +++++++++---
drivers/net/wireless/marvell/mwifiex/scan.c | 18 +++++++++++-------
.../net/wireless/marvell/mwifiex/sta_ioctl.c | 4 ++--
drivers/net/wireless/marvell/mwifiex/wmm.c | 2 +-
4 files changed, 23 insertions(+), 13 deletions(-)
--- a/drivers/net/wireless/marvell/mwifiex/fw.h
+++ b/drivers/net/wireless/marvell/mwifiex/fw.h
@@ -1759,9 +1759,10 @@ struct mwifiex_ie_types_wmm_queue_status
struct ieee_types_vendor_header {
u8 element_id;
u8 len;
- u8 oui[4]; /* 0~2: oui, 3: oui_type */
- u8 oui_subtype;
- u8 version;
+ struct {
+ u8 oui[3];
+ u8 oui_type;
+ } __packed oui;
} __packed;
struct ieee_types_wmm_parameter {
@@ -1775,6 +1776,9 @@ struct ieee_types_wmm_parameter {
* Version [1]
*/
struct ieee_types_vendor_header vend_hdr;
+ u8 oui_subtype;
+ u8 version;
+
u8 qos_info_bitmap;
u8 reserved;
struct ieee_types_wmm_ac_parameters ac_params[IEEE80211_NUM_ACS];
@@ -1792,6 +1796,8 @@ struct ieee_types_wmm_info {
* Version [1]
*/
struct ieee_types_vendor_header vend_hdr;
+ u8 oui_subtype;
+ u8 version;
u8 qos_info_bitmap;
} __packed;
--- a/drivers/net/wireless/marvell/mwifiex/scan.c
+++ b/drivers/net/wireless/marvell/mwifiex/scan.c
@@ -1361,21 +1361,25 @@ int mwifiex_update_bss_desc_with_ie(stru
break;
case WLAN_EID_VENDOR_SPECIFIC:
- if (element_len + 2 < sizeof(vendor_ie->vend_hdr))
- return -EINVAL;
-
vendor_ie = (struct ieee_types_vendor_specific *)
current_ptr;
- if (!memcmp
- (vendor_ie->vend_hdr.oui, wpa_oui,
- sizeof(wpa_oui))) {
+ /* 802.11 requires at least 3-byte OUI. */
+ if (element_len < sizeof(vendor_ie->vend_hdr.oui.oui))
+ return -EINVAL;
+
+ /* Not long enough for a match? Skip it. */
+ if (element_len < sizeof(wpa_oui))
+ break;
+
+ if (!memcmp(&vendor_ie->vend_hdr.oui, wpa_oui,
+ sizeof(wpa_oui))) {
bss_entry->bcn_wpa_ie =
(struct ieee_types_vendor_specific *)
current_ptr;
bss_entry->wpa_offset = (u16)
(current_ptr - bss_entry->beacon_buf);
- } else if (!memcmp(vendor_ie->vend_hdr.oui, wmm_oui,
+ } else if (!memcmp(&vendor_ie->vend_hdr.oui, wmm_oui,
sizeof(wmm_oui))) {
if (total_ie_len ==
sizeof(struct ieee_types_wmm_parameter) ||
--- a/drivers/net/wireless/marvell/mwifiex/sta_ioctl.c
+++ b/drivers/net/wireless/marvell/mwifiex/sta_ioctl.c
@@ -1348,7 +1348,7 @@ mwifiex_set_gen_ie_helper(struct mwifiex
/* Test to see if it is a WPA IE, if not, then
* it is a gen IE
*/
- if (!memcmp(pvendor_ie->oui, wpa_oui,
+ if (!memcmp(&pvendor_ie->oui, wpa_oui,
sizeof(wpa_oui))) {
/* IE is a WPA/WPA2 IE so call set_wpa function
*/
@@ -1358,7 +1358,7 @@ mwifiex_set_gen_ie_helper(struct mwifiex
goto next_ie;
}
- if (!memcmp(pvendor_ie->oui, wps_oui,
+ if (!memcmp(&pvendor_ie->oui, wps_oui,
sizeof(wps_oui))) {
/* Test to see if it is a WPS IE,
* if so, enable wps session flag
--- a/drivers/net/wireless/marvell/mwifiex/wmm.c
+++ b/drivers/net/wireless/marvell/mwifiex/wmm.c
@@ -240,7 +240,7 @@ mwifiex_wmm_setup_queue_priorities(struc
mwifiex_dbg(priv->adapter, INFO,
"info: WMM Parameter IE: version=%d,\t"
"qos_info Parameter Set Count=%d, Reserved=%#x\n",
- wmm_ie->vend_hdr.version, wmm_ie->qos_info_bitmap &
+ wmm_ie->version, wmm_ie->qos_info_bitmap &
IEEE80211_WMM_IE_AP_QOSINFO_PARAM_SET_CNT_MASK,
wmm_ie->reserved);
......@@ -219,6 +219,7 @@ bugfix/all/ext4-zero-out-the-unused-memory-region-in-the-extent.patch
bugfix/all/Bluetooth-hidp-fix-buffer-overflow.patch
bugfix/all/mwifiex-fix-possible-buffer-overflows-at-parsing-bss.patch
bugfix/all/mwifiex-abort-at-too-short-bss-descriptor-element.patch
bugfix/all/mwifiex-don-t-abort-on-small-spec-compliant-vendor-ies.patch
# Fix exported symbol versions
bugfix/all/module-disable-matching-missing-version-crc.patch
......
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