[PATCH][next] wifi: mwifiex: Fix memcpy() field-spanning write warning in mwifiex_cmd_802_11_scan_ext()

[PATCH][next] wifi: mwifiex: Fix memcpy() field-spanning write warning in mwifiex_cmd_802_11_scan_ext()

[Gustavo A. R. Silva]

Replace one-element array with a flexible-array member in
`struct host_cmd_ds_802_11_scan_ext`.

With this, fix the following warning:

elo 16 17:51:58 surfacebook kernel: ------------[ cut here ]------------
elo 16 17:51:58 surfacebook kernel: memcpy: detected field-spanning write (size 243) of single field "ext_scan->tlv_buffer" at drivers/net/wireless/marvell/mwifiex/scan.c:2239 (size 1)
elo 16 17:51:58 surfacebook kernel: WARNING: CPU: 0 PID: 498 at drivers/net/wireless/marvell/mwifiex/scan.c:2239 mwifiex_cmd_802_11_scan_ext+0x83/0x90 [mwifiex]

Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Closes: https://lore.kernel.org/linux-hardening/ZsZNgfnEwOcPdCly@black.fi.intel.com/
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/net/wireless/marvell/mwifiex/fw.h   | 2 +-
 drivers/net/wireless/marvell/mwifiex/scan.c | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/fw.h b/drivers/net/wireless/marvell/mwifiex/fw.h
index e91def0afa14..d03129d5d24e 100644
--- a/drivers/net/wireless/marvell/mwifiex/fw.h
+++ b/drivers/net/wireless/marvell/mwifiex/fw.h
@@ -1627,7 +1627,7 @@ struct host_cmd_ds_802_11_scan_rsp {
 
 struct host_cmd_ds_802_11_scan_ext {
 	u32   reserved;
-	u8    tlv_buffer[1];
+	u8    tlv_buffer[];
 } __packed;
 
 struct mwifiex_ie_types_bss_mode {
diff --git a/drivers/net/wireless/marvell/mwifiex/scan.c b/drivers/net/wireless/marvell/mwifiex/scan.c
index e782d652cb93..f7153472e2a2 100644
--- a/drivers/net/wireless/marvell/mwifiex/scan.c
+++ b/drivers/net/wireless/marvell/mwifiex/scan.c
@@ -2536,8 +2536,7 @@ int mwifiex_ret_802_11_scan_ext(struct mwifiex_private *priv,
 	ext_scan_resp = &resp->params.ext_scan;
 
 	tlv = (void *)ext_scan_resp->tlv_buffer;
-	buf_left = le16_to_cpu(resp->size) - (sizeof(*ext_scan_resp) + S_DS_GEN
-					      - 1);
+	buf_left = le16_to_cpu(resp->size) - (sizeof(*ext_scan_resp) + S_DS_GEN);
 
 	while (buf_left >= sizeof(struct mwifiex_ie_types_header)) {
 		type = le16_to_cpu(tlv->type);
-- 
2.34.1

Re: [PATCH][next] wifi: mwifiex: Fix memcpy() field-spanning write warning in mwifiex_cmd_802_11_scan_ext()

[Andy Shevchenko]

On Wed, Aug 21, 2024 at 03:23:51PM -0600, Gustavo A. R. Silva wrote:
> Replace one-element array with a flexible-array member in
> `struct host_cmd_ds_802_11_scan_ext`.
> 
> With this, fix the following warning:
> 
> elo 16 17:51:58 surfacebook kernel: ------------[ cut here ]------------
> elo 16 17:51:58 surfacebook kernel: memcpy: detected field-spanning write (size 243) of single field "ext_scan->tlv_buffer" at drivers/net/wireless/marvell/mwifiex/scan.c:2239 (size 1)
> elo 16 17:51:58 surfacebook kernel: WARNING: CPU: 0 PID: 498 at drivers/net/wireless/marvell/mwifiex/scan.c:2239 mwifiex_cmd_802_11_scan_ext+0x83/0x90 [mwifiex]

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Thank you!

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH][next] wifi: mwifiex: Fix memcpy() field-spanning write warning in mwifiex_cmd_802_11_scan_ext()

[Brian Norris]

On Wed, Aug 21, 2024 at 03:23:51PM -0600, Gustavo A. R. Silva wrote:
> Replace one-element array with a flexible-array member in
> `struct host_cmd_ds_802_11_scan_ext`.
> 
> With this, fix the following warning:
> 
> elo 16 17:51:58 surfacebook kernel: ------------[ cut here ]------------
> elo 16 17:51:58 surfacebook kernel: memcpy: detected field-spanning write (size 243) of single field "ext_scan->tlv_buffer" at drivers/net/wireless/marvell/mwifiex/scan.c:2239 (size 1)
> elo 16 17:51:58 surfacebook kernel: WARNING: CPU: 0 PID: 498 at drivers/net/wireless/marvell/mwifiex/scan.c:2239 mwifiex_cmd_802_11_scan_ext+0x83/0x90 [mwifiex]
> 
> Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Closes: https://lore.kernel.org/linux-hardening/ZsZNgfnEwOcPdCly@black.fi.intel.com/
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Acked-by: Brian Norris <briannorris@chromium.org>

Re: [PATCH][next] wifi: mwifiex: Fix memcpy() field-spanning write warning in mwifiex_cmd_802_11_scan_ext()

[Kalle Valo]

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

> Replace one-element array with a flexible-array member in
> `struct host_cmd_ds_802_11_scan_ext`.
> 
> With this, fix the following warning:
> 
> elo 16 17:51:58 surfacebook kernel: ------------[ cut here ]------------
> elo 16 17:51:58 surfacebook kernel: memcpy: detected field-spanning write (size 243) of single field "ext_scan->tlv_buffer" at drivers/net/wireless/marvell/mwifiex/scan.c:2239 (size 1)
> elo 16 17:51:58 surfacebook kernel: WARNING: CPU: 0 PID: 498 at drivers/net/wireless/marvell/mwifiex/scan.c:2239 mwifiex_cmd_802_11_scan_ext+0x83/0x90 [mwifiex]
> 
> Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Closes: https://lore.kernel.org/linux-hardening/ZsZNgfnEwOcPdCly@black.fi.intel.com/
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Acked-by: Brian Norris <briannorris@chromium.org>

Patch applied to wireless-next.git, thanks.

498365e52beb wifi: mwifiex: Fix memcpy() field-spanning write warning in mwifiex_cmd_802_11_scan_ext()

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/ZsZa5xRcsLq9D+RX@elsanto/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches