[PATCH 4.9 188/240] wl3501_cs: Fix out-of-bounds warnings in wl3501_mgmt_join

Greg Kroah-Hartman
2021-05-20T11:24:25Z

From: Gustavo A. R. Silva <gustavoars@kernel.org>

[ Upstream commit bb43e5718d8f1b46e7a77e7b39be3c691f293050 ]

Fix the following out-of-bounds warnings by adding a new structure
wl3501_req instead of duplicating the same members in structure
wl3501_join_req and wl3501_scan_confirm:

arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [39, 108] from the object at 'sig' is out of the bounds of referenced subobject 'beacon_period' with type 'short unsigned int' at offset 36 [-Warray-bounds]
arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [25, 95] from the object at 'sig' is out of the bounds of referenced subobject 'beacon_period' with type 'short unsigned int' at offset 22 [-Warray-bounds]

Refactor the code, accordingly:

$ pahole -C wl3501_req drivers/net/wireless/wl3501_cs.o
struct wl3501_req {
u16 beacon_period; /* 0 2 */
u16 dtim_period; /* 2 2 */
u16 cap_info; /* 4 2 */
u8 bss_type; /* 6 1 */
u8 bssid[6]; /* 7 6 */
struct iw_mgmt_essid_pset ssid; /* 13 34 */
struct iw_mgmt_ds_pset ds_pset; /* 47 3 */
struct iw_mgmt_cf_pset cf_pset; /* 50 8 */
struct iw_mgmt_ibss_pset ibss_pset; /* 58 4 */
struct iw_mgmt_data_rset bss_basic_rset; /* 62 10 */

/* size: 72, cachelines: 2, members: 10 */
/* last cacheline: 8 bytes */
};

$ pahole -C wl3501_join_req drivers/net/wireless/wl3501_cs.o
struct wl3501_join_req {
u16 next_blk; /* 0 2 */
u8 sig_id; /* 2 1 */
u8 reserved; /* 3 1 */
struct iw_mgmt_data_rset operational_rset; /* 4 10 */
u16 reserved2; /* 14 2 */
u16 timeout; /* 16 2 */
u16 probe_delay; /* 18 2 */
u8 timestamp[8]; /* 20 8 */
u8 local_time[8]; /* 28 8 */
struct wl3501_req req; /* 36 72 */

/* size: 108, cachelines: 2, members: 10 */
/* last cacheline: 44 bytes */
};

$ pahole -C wl3501_scan_confirm drivers/net/wireless/wl3501_cs.o
struct wl3501_scan_confirm {
u16 next_blk; /* 0 2 */
u8 sig_id; /* 2 1 */
u8 reserved; /* 3 1 */
u16 status; /* 4 2 */
char timestamp[8]; /* 6 8 */
char localtime[8]; /* 14 8 */
struct wl3501_req req; /* 22 72 */
/* --- cacheline 1 boundary (64 bytes) was 30 bytes ago --- */
u8 rssi; /* 94 1 */

/* size: 96, cachelines: 2, members: 8 */
/* padding: 1 */
/* last cacheline: 32 bytes */
};

The problem is that the original code is trying to copy data into a
bunch of struct members adjacent to each other in a single call to
memcpy(). Now that a new struct wl3501_req enclosing all those adjacent
members is introduced, memcpy() doesn't overrun the length of
&sig.beacon_period and &this->bss_set[i].beacon_period, because the
address of the new struct object _req_ is used as the destination,
instead.

This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().

Link: https://github.com/KSPP/linux/issues/109
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1fbaf516da763b50edac47d792a9145aa4482e29.1618442265.git.gustavoars@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/wl3501.h | 35 +++++++++++--------------
drivers/net/wireless/wl3501_cs.c | 44 +++++++++++++++++---------------
2 files changed, 38 insertions(+), 41 deletions(-)

diff --git a/drivers/net/wireless/wl3501.h b/drivers/net/wireless/wl3501.h
index ba2a36cfb1c8..ca2021bcac14 100644
--- a/drivers/net/wireless/wl3501.h
+++ b/drivers/net/wireless/wl3501.h
@@ -378,16 +378,7 @@ struct wl3501_get_confirm {
u8 mib_value[100];
};

-struct wl3501_join_req {
- u16 next_blk;
- u8 sig_id;
- u8 reserved;
- struct iw_mgmt_data_rset operational_rset;
- u16 reserved2;
- u16 timeout;
- u16 probe_delay;
- u8 timestamp[8];
- u8 local_time[8];
+struct wl3501_req {
u16 beacon_period;
u16 dtim_period;
u16 cap_info;
@@ -400,6 +391,19 @@ struct wl3501_join_req {
struct iw_mgmt_data_rset bss_basic_rset;
};

+struct wl3501_join_req {
+ u16 next_blk;
+ u8 sig_id;
+ u8 reserved;
+ struct iw_mgmt_data_rset operational_rset;
+ u16 reserved2;
+ u16 timeout;
+ u16 probe_delay;
+ u8 timestamp[8];
+ u8 local_time[8];
+ struct wl3501_req req;
+};
+
struct wl3501_join_confirm {
u16 next_blk;
u8 sig_id;
@@ -442,16 +446,7 @@ struct wl3501_scan_confirm {
u16 status;
char timestamp[8];
char localtime[8];
- u16 beacon_period;
- u16 dtim_period;
- u16 cap_info;
- u8 bss_type;
- u8 bssid[ETH_ALEN];
- struct iw_mgmt_essid_pset ssid;
- struct iw_mgmt_ds_pset ds_pset;
- struct iw_mgmt_cf_pset cf_pset;
- struct iw_mgmt_ibss_pset ibss_pset;
- struct iw_mgmt_data_rset bss_basic_rset;
+ struct wl3501_req req;
u8 rssi;
};

diff --git a/drivers/net/wireless/wl3501_cs.c b/drivers/net/wireless/wl3501_cs.c
index f49a44581ede..959844a10861 100644
--- a/drivers/net/wireless/wl3501_cs.c
+++ b/drivers/net/wireless/wl3501_cs.c
@@ -589,7 +589,7 @@ static int wl3501_mgmt_join(struct wl3501_card *this, u16 stas)
struct wl3501_join_req sig = {
.sig_id = WL3501_SIG_JOIN_REQ,
.timeout = 10,
- .ds_pset = {
+ .req.ds_pset = {
.el = {
.id = IW_MGMT_INFO_ELEMENT_DS_PARAMETER_SET,
.len = 1,
@@ -598,7 +598,7 @@ static int wl3501_mgmt_join(struct wl3501_card *this, u16 stas)
},
};

- memcpy(&sig.beacon_period, &this->bss_set[stas].beacon_period, 72);
+ memcpy(&sig.req, &this->bss_set[stas].req, sizeof(sig.req));
return wl3501_esbq_exec(this, &sig, sizeof(sig));
}

@@ -666,35 +666,37 @@ static void wl3501_mgmt_scan_confirm(struct wl3501_card *this, u16 addr)
if (sig.status == WL3501_STATUS_SUCCESS) {
pr_debug("success");
if ((this->net_type == IW_MODE_INFRA &&
- (sig.cap_info & WL3501_MGMT_CAPABILITY_ESS)) ||
+ (sig.req.cap_info & WL3501_MGMT_CAPABILITY_ESS)) ||
(this->net_type == IW_MODE_ADHOC &&
- (sig.cap_info & WL3501_MGMT_CAPABILITY_IBSS)) ||
+ (sig.req.cap_info & WL3501_MGMT_CAPABILITY_IBSS)) ||
this->net_type == IW_MODE_AUTO) {
if (!this->essid.el.len)
matchflag = 1;
else if (this->essid.el.len == 3 &&
!memcmp(this->essid.essid, "ANY", 3))
matchflag = 1;
- else if (this->essid.el.len != sig.ssid.el.len)
+ else if (this->essid.el.len != sig.req.ssid.el.len)
matchflag = 0;
- else if (memcmp(this->essid.essid, sig.ssid.essid,
+ else if (memcmp(this->essid.essid, sig.req.ssid.essid,
this->essid.el.len))
matchflag = 0;
else
matchflag = 1;
if (matchflag) {
for (i = 0; i < this->bss_cnt; i++) {
- if (ether_addr_equal_unaligned(this->bss_set[i].bssid, sig.bssid)) {
+ if (ether_addr_equal_unaligned(this->bss_set[i].req.bssid,
+ sig.req.bssid)) {
matchflag = 0;
break;
}
}
}
if (matchflag && (i < 20)) {
- memcpy(&this->bss_set[i].beacon_period,
- &sig.beacon_period, 73);
+ memcpy(&this->bss_set[i].req,
+ &sig.req, sizeof(sig.req));
this->bss_cnt++;
this->rssi = sig.rssi;
+ this->bss_set[i].rssi = sig.rssi;
}
}
} else if (sig.status == WL3501_STATUS_TIMEOUT) {
@@ -886,19 +888,19 @@ static void wl3501_mgmt_join_confirm(struct net_device *dev, u16 addr)
if (this->join_sta_bss < this->bss_cnt) {
const int i = this->join_sta_bss;
memcpy(this->bssid,
- this->bss_set[i].bssid, ETH_ALEN);
- this->chan = this->bss_set[i].ds_pset.chan;
+ this->bss_set[i].req.bssid, ETH_ALEN);
+ this->chan = this->bss_set[i].req.ds_pset.chan;
iw_copy_mgmt_info_element(&this->keep_essid.el,
- &this->bss_set[i].ssid.el);
+ &this->bss_set[i].req.ssid.el);
wl3501_mgmt_auth(this);
}
} else {
const int i = this->join_sta_bss;

- memcpy(&this->bssid, &this->bss_set[i].bssid, ETH_ALEN);
- this->chan = this->bss_set[i].ds_pset.chan;
+ memcpy(&this->bssid, &this->bss_set[i].req.bssid, ETH_ALEN);
+ this->chan = this->bss_set[i].req.ds_pset.chan;
iw_copy_mgmt_info_element(&this->keep_essid.el,
- &this->bss_set[i].ssid.el);
+ &this->bss_set[i].req.ssid.el);
wl3501_online(dev);
}
} else {
@@ -1576,30 +1578,30 @@ static int wl3501_get_scan(struct net_device *dev, struct iw_request_info *info,
for (i = 0; i < this->bss_cnt; ++i) {
iwe.cmd = SIOCGIWAP;
iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
- memcpy(iwe.u.ap_addr.sa_data, this->bss_set[i].bssid, ETH_ALEN);
+ memcpy(iwe.u.ap_addr.sa_data, this->bss_set[i].req.bssid, ETH_ALEN);
current_ev = iwe_stream_add_event(info, current_ev,
extra + IW_SCAN_MAX_DATA,
&iwe, IW_EV_ADDR_LEN);
iwe.cmd = SIOCGIWESSID;
iwe.u.data.flags = 1;
- iwe.u.data.length = this->bss_set[i].ssid.el.len;
+ iwe.u.data.length = this->bss_set[i].req.ssid.el.len;
current_ev = iwe_stream_add_point(info, current_ev,
extra + IW_SCAN_MAX_DATA,
&iwe,
- this->bss_set[i].ssid.essid);
+ this->bss_set[i].req.ssid.essid);
iwe.cmd = SIOCGIWMODE;
- iwe.u.mode = this->bss_set[i].bss_type;
+ iwe.u.mode = this->bss_set[i].req.bss_type;
current_ev = iwe_stream_add_event(info, current_ev,
extra + IW_SCAN_MAX_DATA,
&iwe, IW_EV_UINT_LEN);
iwe.cmd = SIOCGIWFREQ;
- iwe.u.freq.m = this->bss_set[i].ds_pset.chan;
+ iwe.u.freq.m = this->bss_set[i].req.ds_pset.chan;
iwe.u.freq.e = 0;
current_ev = iwe_stream_add_event(info, current_ev,
extra + IW_SCAN_MAX_DATA,
&iwe, IW_EV_FREQ_LEN);
iwe.cmd = SIOCGIWENCODE;
- if (this->bss_set[i].cap_info & WL3501_MGMT_CAPABILITY_PRIVACY)
+ if (this->bss_set[i].req.cap_info & WL3501_MGMT_CAPABILITY_PRIVACY)
iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
else
iwe.u.data.flags = IW_ENCODE_DISABLED;
--
2.30.2