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staging: rtl8192u: Avoid field-overflowing memcpy()

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In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Split the 3 addr memcpy() into 3 memcpy() calls so the compiler doesn't
think an overflowing memcpy() happens against the addr1 field (the
neighbors are intended to be copied as well).

ieee80211_read_qos_param_element() copies a struct ieee80211_info_element
into a struct ieee80211_qos_information_element, but is actually wanting to
copy into the larger struct ieee80211_qos_parameter_info (the contents of
ac_params_record[] is later examined). Refactor the routine to perform
centralized checks, and copy the entire contents directly (since the id
and len members match the elementID and length members):

struct ieee80211_info_element {
        u8 id;
        u8 len;
        u8 data[];
} __packed;

struct ieee80211_qos_information_element {
        u8 elementID;
        u8 length;
        u8 qui[QOS_OUI_LEN];
        u8 qui_type;
        u8 qui_subtype;
        u8 version;
        u8 ac_info;
} __packed;

struct ieee80211_qos_parameter_info {
        struct ieee80211_qos_information_element info_element;
        u8 reserved;
        struct ieee80211_qos_ac_parameter ac_params_record[QOS_QUEUE_NUM];
} __packed;

Additionally replace old-style zero-element arrays with flexible arrays.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Pascal Terjan <pterjan@google.com>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: devel@driverdev.osuosl.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210806201208.2871467-1-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Kees Cook 2021-08-06 13:12:07 -07:00 committed by Greg Kroah-Hartman
parent ada0e6dbbb
commit 1b3c6cccda
3 changed files with 19 additions and 38 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/staging/rtl8192u/ieee80211/ieee80211.h
View File

@ -303,7 +303,7 @@ struct ieee_param {
struct {
u32 len;
u8 reserved[32];
u8 data[0];
u8 data[];
} wpa_ie;
struct{
int command;
@ -316,7 +316,7 @@ struct ieee_param {
u8 idx;
u8 seq[8]; /* sequence counter (set: RX, get: TX) */
u16 key_len;
u8 key[0];
u8 key[];
} crypt;
} u;
};

4
drivers/staging/rtl8192u/ieee80211/ieee80211_crypt_ccmp.c
View File

@ -141,7 +141,9 @@ static int ccmp_init_iv_and_aad(struct rtl_80211_hdr_4addr *hdr,
pos = (u8 *)hdr;
aad[0] = pos[0] & 0x8f;
aad[1] = pos[1] & 0xc7;
memcpy(aad + 2, hdr->addr1, 3 * ETH_ALEN);
memcpy(&aad[2], &hdr->addr1, ETH_ALEN);
memcpy(&aad[8], &hdr->addr2, ETH_ALEN);
memcpy(&aad[14], &hdr->addr3, ETH_ALEN);
pos = (u8 *)&hdr->seq_ctl;
aad[20] = pos[0] & 0x0f;
aad[21] = 0; /* all bits masked */

49
drivers/staging/rtl8192u/ieee80211/ieee80211_rx.c
View File

@ -1310,7 +1310,8 @@ static u8 qos_oui[QOS_OUI_LEN] = { 0x00, 0x50, 0xF2 };
static int ieee80211_verify_qos_info(struct ieee80211_qos_information_element
*info_element, int sub_type)
{
if (info_element->elementID != QOS_ELEMENT_ID)
return -1;
if (info_element->qui_subtype != sub_type)
return -1;
if (memcmp(info_element->qui, qos_oui, QOS_OUI_LEN))
@ -1327,27 +1328,18 @@ static int ieee80211_verify_qos_info(struct ieee80211_qos_information_element
/*
* Parse a QoS parameter element
*/
static int ieee80211_read_qos_param_element(struct ieee80211_qos_parameter_info
*element_param, struct ieee80211_info_element
*info_element)
static int ieee80211_read_qos_param_element(
struct ieee80211_qos_parameter_info *element_param,
struct ieee80211_info_element *info_element)
{
int ret = 0;
u16 size = sizeof(struct ieee80211_qos_parameter_info) - 2;
size_t size = sizeof(*element_param);
if (!info_element || !element_param)
if (!element_param || !info_element || info_element->len != size - 2)
return -1;
if (info_element->id == QOS_ELEMENT_ID && info_element->len == size) {
memcpy(element_param->info_element.qui, info_element->data,
info_element->len);
element_param->info_element.elementID = info_element->id;
element_param->info_element.length = info_element->len;
} else
ret = -1;
if (ret == 0)
ret = ieee80211_verify_qos_info(&element_param->info_element,
QOS_OUI_PARAM_SUB_TYPE);
return ret;
memcpy(element_param, info_element, size);
return ieee80211_verify_qos_info(&element_param->info_element,
QOS_OUI_PARAM_SUB_TYPE);
}
/*
@ -1357,26 +1349,13 @@ static int ieee80211_read_qos_info_element(
struct ieee80211_qos_information_element *element_info,
struct ieee80211_info_element *info_element)
{
int ret = 0;
u16 size = sizeof(struct ieee80211_qos_information_element) - 2;
size_t size = sizeof(*element_info);
if (!element_info)
return -1;
if (!info_element)
if (!element_info || !info_element || info_element->len != size - 2)
return -1;
if ((info_element->id == QOS_ELEMENT_ID) && (info_element->len == size)) {
memcpy(element_info->qui, info_element->data,
info_element->len);
element_info->elementID = info_element->id;
element_info->length = info_element->len;
} else
ret = -1;
if (ret == 0)
ret = ieee80211_verify_qos_info(element_info,
QOS_OUI_INFO_SUB_TYPE);
return ret;
memcpy(element_info, info_element, size);
return ieee80211_verify_qos_info(element_info, QOS_OUI_INFO_SUB_TYPE);
}