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* [PATCH 0/3] wifi: mwifiex: Fix tlv_buf_left calculation and replace one-element array
@ 2023-08-23 22:29 Gustavo A. R. Silva
  2023-08-23 22:30 ` [PATCH 1/3] wifi: mwifiex: Fix tlv_buf_left calculation Gustavo A. R. Silva
                   ` (2 more replies)
  0 siblings, 3 replies; 8+ messages in thread
From: Gustavo A. R. Silva @ 2023-08-23 22:29 UTC (permalink / raw)
  To: Brian Norris, Kalle Valo, Amitkumar Karwar, Xinming Hu, Dan Williams
  Cc: linux-wireless, linux-kernel, Gustavo A. R. Silva, linux-hardening

Hi all!

This small series is aimed at fixing a bug in the tlv_buf_left
calculation, doing a flexible-array transformation, and adding
a couple of sanity checks.

Thanks

Gustavo A. R. Silva (3):
  wifi: mwifiex: Fix tlv_buf_left calculation
  wifi: mwifiex: Replace one-element array with flexible-array member in
    struct mwifiex_ie_types_rxba_sync
  wifi: mwifiex: Sanity check tlv_len and tlv_bitmap_len

 .../wireless/marvell/mwifiex/11n_rxreorder.c  | 22 ++++++++++++++++---
 drivers/net/wireless/marvell/mwifiex/fw.h     |  2 +-
 2 files changed, 20 insertions(+), 4 deletions(-)

-- 
2.34.1


^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH 1/3] wifi: mwifiex: Fix tlv_buf_left calculation
  2023-08-23 22:29 [PATCH 0/3] wifi: mwifiex: Fix tlv_buf_left calculation and replace one-element array Gustavo A. R. Silva
@ 2023-08-23 22:30 ` Gustavo A. R. Silva
  2023-08-23 22:37   ` Justin Stitt
  2023-08-23 22:32 ` [PATCH 2/3] wifi: mwifiex: Replace one-element array with flexible-array member in struct mwifiex_ie_types_rxba_sync Gustavo A. R. Silva
  2023-08-23 22:33 ` [PATCH 3/3] wifi: mwifiex: Sanity check tlv_len and tlv_bitmap_len Gustavo A. R. Silva
  2 siblings, 1 reply; 8+ messages in thread
From: Gustavo A. R. Silva @ 2023-08-23 22:30 UTC (permalink / raw)
  To: Brian Norris, Kalle Valo, Amitkumar Karwar, Xinming Hu, Dan Williams
  Cc: linux-wireless, linux-kernel, Gustavo A. R. Silva, linux-hardening

In a TLV encoding scheme, the Length part represents the length after
the header containing the values for type and length. In this case,
`tlv_len` should be:

tlv_len == (sizeof(*tlv_rxba) - 1) - sizeof(tlv_rxba->header) + tlv_bitmap_len

Notice that the `- 1` accounts for the one-element array `bitmap`, which
1-byte size is already included in `sizeof(*tlv_rxba)`.

So, if the above is correct, there is a double-counting of some members
in `struct mwifiex_ie_types_rxba_sync`, when `tlv_buf_left` and `tmp`
are calculated:

968                 tlv_buf_left -= (sizeof(*tlv_rxba) + tlv_len);
969                 tmp = (u8 *)tlv_rxba + tlv_len + sizeof(*tlv_rxba);

in specific, members:

drivers/net/wireless/marvell/mwifiex/fw.h:777
 777         u8 mac[ETH_ALEN];
 778         u8 tid;
 779         u8 reserved;
 780         __le16 seq_num;
 781         __le16 bitmap_len;

This is clearly wrong, and affects the subsequent decoding of data from
`event_buf` through `tlv_rxba`:

970                 tlv_rxba = (struct mwifiex_ie_types_rxba_sync *)tmp;

Fix this by using `sizeof(tlv_rxba->header)` instead of `sizeof(*tlv_rxba)`
in the calculation of `tlv_buf_left` and `tmp`.

This results in the following binary differences before/after changes:

| drivers/net/wireless/marvell/mwifiex/11n_rxreorder.o
| @@ -4698,11 +4698,11 @@
|                 tlv_buf_left -= (sizeof(tlv_rxba->header) + tlv_len);
| -    1da7:      lea    -0x11(%rbx),%edx
| +    1da7:      lea    -0x4(%rbx),%edx
|      1daa:      movzwl %bp,%eax
|  drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c:969
|                 tmp = (u8 *)tlv_rxba  + sizeof(tlv_rxba->header) + tlv_len;
| -    1dad:      lea    0x11(%r15,%rbp,1),%r15
| +    1dad:      lea    0x4(%r15,%rbp,1),%r15
|  drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c:968
|                 tlv_buf_left -= (sizeof(tlv_rxba->header) + tlv_len);
|      1db2:      mov    %edx,%ebx

The above reflects the desired change: avoid counting 13 too bytes;
which is the total size of the double-counted members in
`struct mwifiex_ie_types_rxba_sync`:

$ pahole -C mwifiex_ie_types_rxba_sync drivers/net/wireless/marvell/mwifiex/11n_rxreorder.o
struct mwifiex_ie_types_rxba_sync {
	struct mwifiex_ie_types_header header;           /*     0     4 */

     |-----------------------------------------------------------------------
     |  u8                         mac[6];               /*     4     6 */  |
     |	u8                         tid;                  /*    10     1 */  |
     |  u8                         reserved;             /*    11     1 */  |
     | 	__le16                     seq_num;              /*    12     2 */  |
     | 	__le16                     bitmap_len;           /*    14     2 */  |
     |  u8                         bitmap[1];            /*    16     1 */  |
     |----------------------------------------------------------------------|
								  | 13 bytes|
								  -----------

	/* size: 17, cachelines: 1, members: 7 */
	/* last cacheline: 17 bytes */
} __attribute__((__packed__));

Fixes: 99ffe72cdae4 ("mwifiex: process rxba_sync event")
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
index 391793a16adc..d1d3632a3ed7 100644
--- a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
+++ b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
@@ -965,8 +965,8 @@ void mwifiex_11n_rxba_sync_event(struct mwifiex_private *priv,
 			}
 		}
 
-		tlv_buf_left -= (sizeof(*tlv_rxba) + tlv_len);
-		tmp = (u8 *)tlv_rxba + tlv_len + sizeof(*tlv_rxba);
+		tlv_buf_left -= (sizeof(tlv_rxba->header) + tlv_len);
+		tmp = (u8 *)tlv_rxba  + sizeof(tlv_rxba->header) + tlv_len;
 		tlv_rxba = (struct mwifiex_ie_types_rxba_sync *)tmp;
 	}
 }
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH 2/3] wifi: mwifiex: Replace one-element array with flexible-array member in struct mwifiex_ie_types_rxba_sync
  2023-08-23 22:29 [PATCH 0/3] wifi: mwifiex: Fix tlv_buf_left calculation and replace one-element array Gustavo A. R. Silva
  2023-08-23 22:30 ` [PATCH 1/3] wifi: mwifiex: Fix tlv_buf_left calculation Gustavo A. R. Silva
@ 2023-08-23 22:32 ` Gustavo A. R. Silva
  2023-08-23 22:38   ` Justin Stitt
  2023-08-23 22:33 ` [PATCH 3/3] wifi: mwifiex: Sanity check tlv_len and tlv_bitmap_len Gustavo A. R. Silva
  2 siblings, 1 reply; 8+ messages in thread
From: Gustavo A. R. Silva @ 2023-08-23 22:32 UTC (permalink / raw)
  To: Brian Norris, Kalle Valo, Amitkumar Karwar, Xinming Hu, Dan Williams
  Cc: linux-wireless, linux-kernel, Gustavo A. R. Silva, linux-hardening

One-element and zero-length arrays are deprecated. So, replace
one-element array in struct mwifiex_ie_types_rxba_sync with
flexible-array member, and refactor the rest of the code, accordingly.

This results in no differences in binary output.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c | 2 +-
 drivers/net/wireless/marvell/mwifiex/fw.h            | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
index d1d3632a3ed7..735aac52bdc4 100644
--- a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
+++ b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
@@ -918,7 +918,7 @@ void mwifiex_11n_rxba_sync_event(struct mwifiex_private *priv,
 
 	mwifiex_dbg_dump(priv->adapter, EVT_D, "RXBA_SYNC event:",
 			 event_buf, len);
-	while (tlv_buf_left >= sizeof(*tlv_rxba)) {
+	while (tlv_buf_left > sizeof(*tlv_rxba)) {
 		tlv_type = le16_to_cpu(tlv_rxba->header.type);
 		tlv_len  = le16_to_cpu(tlv_rxba->header.len);
 		if (tlv_type != TLV_TYPE_RXBA_SYNC) {
diff --git a/drivers/net/wireless/marvell/mwifiex/fw.h b/drivers/net/wireless/marvell/mwifiex/fw.h
index f2168fac95ed..8e6db904e5b2 100644
--- a/drivers/net/wireless/marvell/mwifiex/fw.h
+++ b/drivers/net/wireless/marvell/mwifiex/fw.h
@@ -779,7 +779,7 @@ struct mwifiex_ie_types_rxba_sync {
 	u8 reserved;
 	__le16 seq_num;
 	__le16 bitmap_len;
-	u8 bitmap[1];
+	u8 bitmap[];
 } __packed;
 
 struct chan_band_param_set {
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH 3/3] wifi: mwifiex: Sanity check tlv_len and tlv_bitmap_len
  2023-08-23 22:29 [PATCH 0/3] wifi: mwifiex: Fix tlv_buf_left calculation and replace one-element array Gustavo A. R. Silva
  2023-08-23 22:30 ` [PATCH 1/3] wifi: mwifiex: Fix tlv_buf_left calculation Gustavo A. R. Silva
  2023-08-23 22:32 ` [PATCH 2/3] wifi: mwifiex: Replace one-element array with flexible-array member in struct mwifiex_ie_types_rxba_sync Gustavo A. R. Silva
@ 2023-08-23 22:33 ` Gustavo A. R. Silva
  2023-08-23 22:38   ` Justin Stitt
  2023-08-24  1:07   ` kernel test robot
  2 siblings, 2 replies; 8+ messages in thread
From: Gustavo A. R. Silva @ 2023-08-23 22:33 UTC (permalink / raw)
  To: Brian Norris, Kalle Valo, Amitkumar Karwar, Xinming Hu, Dan Williams
  Cc: linux-wireless, linux-kernel, Gustavo A. R. Silva, linux-hardening

Add sanity checks for both `tlv_len` and `tlv_bitmap_len` before
decoding data from `event_buf`.

This prevents any malicious or buggy firmware from overflowing
`event_buf` through large values for `tlv_len` or `tlv_bitmap_len`.

Suggested-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 .../net/wireless/marvell/mwifiex/11n_rxreorder.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
index 735aac52bdc4..9ee3b9f1e9ce 100644
--- a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
+++ b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
@@ -921,6 +921,14 @@ void mwifiex_11n_rxba_sync_event(struct mwifiex_private *priv,
 	while (tlv_buf_left > sizeof(*tlv_rxba)) {
 		tlv_type = le16_to_cpu(tlv_rxba->header.type);
 		tlv_len  = le16_to_cpu(tlv_rxba->header.len);
+		if (size_add(sizeof(tlv_rxba->header), tlv_len) > tlv_buf_left) {
+			mwifiex_dbg(priv->adapter, WARN,
+				    "TLV size (%ld) overflows event_buf (%d)\n",
+				    size_add(sizeof(tlv_rxba->header), tlv_len),
+				    tlv_buf_left);
+			return;
+		}
+
 		if (tlv_type != TLV_TYPE_RXBA_SYNC) {
 			mwifiex_dbg(priv->adapter, ERROR,
 				    "Wrong TLV id=0x%x\n", tlv_type);
@@ -929,6 +937,14 @@ void mwifiex_11n_rxba_sync_event(struct mwifiex_private *priv,
 
 		tlv_seq_num = le16_to_cpu(tlv_rxba->seq_num);
 		tlv_bitmap_len = le16_to_cpu(tlv_rxba->bitmap_len);
+		if (size_add(sizeof(*tlv_rxba), tlv_bitmap_len) > tlv_buf_left) {
+			mwifiex_dbg(priv->adapter, WARN,
+				    "TLV size (%ld) overflows event_buf (%d)\n",
+				    size_add(sizeof(*tlv_rxba), tlv_bitmap_len),
+				    tlv_buf_left);
+			return;
+		}
+
 		mwifiex_dbg(priv->adapter, INFO,
 			    "%pM tid=%d seq_num=%d bitmap_len=%d\n",
 			    tlv_rxba->mac, tlv_rxba->tid, tlv_seq_num,
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH 1/3] wifi: mwifiex: Fix tlv_buf_left calculation
  2023-08-23 22:30 ` [PATCH 1/3] wifi: mwifiex: Fix tlv_buf_left calculation Gustavo A. R. Silva
@ 2023-08-23 22:37   ` Justin Stitt
  0 siblings, 0 replies; 8+ messages in thread
From: Justin Stitt @ 2023-08-23 22:37 UTC (permalink / raw)
  To: Gustavo A. R. Silva
  Cc: Brian Norris, Kalle Valo, Amitkumar Karwar, Xinming Hu,
	Dan Williams, linux-wireless, linux-kernel, linux-hardening

On Wed, Aug 23, 2023 at 3:30 PM Gustavo A. R. Silva
<gustavoars@kernel.org> wrote:
>
> In a TLV encoding scheme, the Length part represents the length after
> the header containing the values for type and length. In this case,
> `tlv_len` should be:
>
> tlv_len == (sizeof(*tlv_rxba) - 1) - sizeof(tlv_rxba->header) + tlv_bitmap_len
>
> Notice that the `- 1` accounts for the one-element array `bitmap`, which
> 1-byte size is already included in `sizeof(*tlv_rxba)`.
>
> So, if the above is correct, there is a double-counting of some members
> in `struct mwifiex_ie_types_rxba_sync`, when `tlv_buf_left` and `tmp`
> are calculated:
>
> 968                 tlv_buf_left -= (sizeof(*tlv_rxba) + tlv_len);
> 969                 tmp = (u8 *)tlv_rxba + tlv_len + sizeof(*tlv_rxba);
>
> in specific, members:
>
> drivers/net/wireless/marvell/mwifiex/fw.h:777
>  777         u8 mac[ETH_ALEN];
>  778         u8 tid;
>  779         u8 reserved;
>  780         __le16 seq_num;
>  781         __le16 bitmap_len;
>
> This is clearly wrong, and affects the subsequent decoding of data from
> `event_buf` through `tlv_rxba`:
>
> 970                 tlv_rxba = (struct mwifiex_ie_types_rxba_sync *)tmp;
>
> Fix this by using `sizeof(tlv_rxba->header)` instead of `sizeof(*tlv_rxba)`
> in the calculation of `tlv_buf_left` and `tmp`.
>
> This results in the following binary differences before/after changes:
>
> | drivers/net/wireless/marvell/mwifiex/11n_rxreorder.o
> | @@ -4698,11 +4698,11 @@
> |                 tlv_buf_left -= (sizeof(tlv_rxba->header) + tlv_len);
> | -    1da7:      lea    -0x11(%rbx),%edx
> | +    1da7:      lea    -0x4(%rbx),%edx
> |      1daa:      movzwl %bp,%eax
> |  drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c:969
> |                 tmp = (u8 *)tlv_rxba  + sizeof(tlv_rxba->header) + tlv_len;
> | -    1dad:      lea    0x11(%r15,%rbp,1),%r15
> | +    1dad:      lea    0x4(%r15,%rbp,1),%r15
> |  drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c:968
> |                 tlv_buf_left -= (sizeof(tlv_rxba->header) + tlv_len);
> |      1db2:      mov    %edx,%ebx
>
> The above reflects the desired change: avoid counting 13 too bytes;
> which is the total size of the double-counted members in
> `struct mwifiex_ie_types_rxba_sync`:
>
> $ pahole -C mwifiex_ie_types_rxba_sync drivers/net/wireless/marvell/mwifiex/11n_rxreorder.o
> struct mwifiex_ie_types_rxba_sync {
>         struct mwifiex_ie_types_header header;           /*     0     4 */
>
>      |-----------------------------------------------------------------------
>      |  u8                         mac[6];               /*     4     6 */  |
>      |  u8                         tid;                  /*    10     1 */  |
>      |  u8                         reserved;             /*    11     1 */  |
>      |  __le16                     seq_num;              /*    12     2 */  |
>      |  __le16                     bitmap_len;           /*    14     2 */  |
>      |  u8                         bitmap[1];            /*    16     1 */  |
>      |----------------------------------------------------------------------|
>                                                                   | 13 bytes|
>                                                                   -----------
>
>         /* size: 17, cachelines: 1, members: 7 */
>         /* last cacheline: 17 bytes */
> } __attribute__((__packed__));
>
> Fixes: 99ffe72cdae4 ("mwifiex: process rxba_sync event")
> Cc: stable@vger.kernel.org
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Justin Stitt <justinstitt@google.com>

> ---
>  drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
> index 391793a16adc..d1d3632a3ed7 100644
> --- a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
> +++ b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
> @@ -965,8 +965,8 @@ void mwifiex_11n_rxba_sync_event(struct mwifiex_private *priv,
>                         }
>                 }
>
> -               tlv_buf_left -= (sizeof(*tlv_rxba) + tlv_len);
> -               tmp = (u8 *)tlv_rxba + tlv_len + sizeof(*tlv_rxba);
> +               tlv_buf_left -= (sizeof(tlv_rxba->header) + tlv_len);
> +               tmp = (u8 *)tlv_rxba  + sizeof(tlv_rxba->header) + tlv_len;
>                 tlv_rxba = (struct mwifiex_ie_types_rxba_sync *)tmp;
>         }
>  }
> --
> 2.34.1
>

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH 2/3] wifi: mwifiex: Replace one-element array with flexible-array member in struct mwifiex_ie_types_rxba_sync
  2023-08-23 22:32 ` [PATCH 2/3] wifi: mwifiex: Replace one-element array with flexible-array member in struct mwifiex_ie_types_rxba_sync Gustavo A. R. Silva
@ 2023-08-23 22:38   ` Justin Stitt
  0 siblings, 0 replies; 8+ messages in thread
From: Justin Stitt @ 2023-08-23 22:38 UTC (permalink / raw)
  To: Gustavo A. R. Silva
  Cc: Brian Norris, Kalle Valo, Amitkumar Karwar, Xinming Hu,
	Dan Williams, linux-wireless, linux-kernel, linux-hardening

On Wed, Aug 23, 2023 at 3:32 PM Gustavo A. R. Silva
<gustavoars@kernel.org> wrote:
>
> One-element and zero-length arrays are deprecated. So, replace
> one-element array in struct mwifiex_ie_types_rxba_sync with
> flexible-array member, and refactor the rest of the code, accordingly.
>
> This results in no differences in binary output.
>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Justin Stitt <justinstitt@google.com>

> ---
>  drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c | 2 +-
>  drivers/net/wireless/marvell/mwifiex/fw.h            | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
> index d1d3632a3ed7..735aac52bdc4 100644
> --- a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
> +++ b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
> @@ -918,7 +918,7 @@ void mwifiex_11n_rxba_sync_event(struct mwifiex_private *priv,
>
>         mwifiex_dbg_dump(priv->adapter, EVT_D, "RXBA_SYNC event:",
>                          event_buf, len);
> -       while (tlv_buf_left >= sizeof(*tlv_rxba)) {
> +       while (tlv_buf_left > sizeof(*tlv_rxba)) {
>                 tlv_type = le16_to_cpu(tlv_rxba->header.type);
>                 tlv_len  = le16_to_cpu(tlv_rxba->header.len);
>                 if (tlv_type != TLV_TYPE_RXBA_SYNC) {
> diff --git a/drivers/net/wireless/marvell/mwifiex/fw.h b/drivers/net/wireless/marvell/mwifiex/fw.h
> index f2168fac95ed..8e6db904e5b2 100644
> --- a/drivers/net/wireless/marvell/mwifiex/fw.h
> +++ b/drivers/net/wireless/marvell/mwifiex/fw.h
> @@ -779,7 +779,7 @@ struct mwifiex_ie_types_rxba_sync {
>         u8 reserved;
>         __le16 seq_num;
>         __le16 bitmap_len;
> -       u8 bitmap[1];
> +       u8 bitmap[];
>  } __packed;
>
>  struct chan_band_param_set {
> --
> 2.34.1
>

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH 3/3] wifi: mwifiex: Sanity check tlv_len and tlv_bitmap_len
  2023-08-23 22:33 ` [PATCH 3/3] wifi: mwifiex: Sanity check tlv_len and tlv_bitmap_len Gustavo A. R. Silva
@ 2023-08-23 22:38   ` Justin Stitt
  2023-08-24  1:07   ` kernel test robot
  1 sibling, 0 replies; 8+ messages in thread
From: Justin Stitt @ 2023-08-23 22:38 UTC (permalink / raw)
  To: Gustavo A. R. Silva
  Cc: Brian Norris, Kalle Valo, Amitkumar Karwar, Xinming Hu,
	Dan Williams, linux-wireless, linux-kernel, linux-hardening

On Wed, Aug 23, 2023 at 3:33 PM Gustavo A. R. Silva
<gustavoars@kernel.org> wrote:
>
> Add sanity checks for both `tlv_len` and `tlv_bitmap_len` before
> decoding data from `event_buf`.
>
> This prevents any malicious or buggy firmware from overflowing
> `event_buf` through large values for `tlv_len` or `tlv_bitmap_len`.
>
> Suggested-by: Dan Williams <dcbw@redhat.com>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Justin Stitt <justinstitt@google.com>

> ---
>  .../net/wireless/marvell/mwifiex/11n_rxreorder.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
>
> diff --git a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
> index 735aac52bdc4..9ee3b9f1e9ce 100644
> --- a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
> +++ b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
> @@ -921,6 +921,14 @@ void mwifiex_11n_rxba_sync_event(struct mwifiex_private *priv,
>         while (tlv_buf_left > sizeof(*tlv_rxba)) {
>                 tlv_type = le16_to_cpu(tlv_rxba->header.type);
>                 tlv_len  = le16_to_cpu(tlv_rxba->header.len);
> +               if (size_add(sizeof(tlv_rxba->header), tlv_len) > tlv_buf_left) {
> +                       mwifiex_dbg(priv->adapter, WARN,
> +                                   "TLV size (%ld) overflows event_buf (%d)\n",
> +                                   size_add(sizeof(tlv_rxba->header), tlv_len),
> +                                   tlv_buf_left);
> +                       return;
> +               }
> +
>                 if (tlv_type != TLV_TYPE_RXBA_SYNC) {
>                         mwifiex_dbg(priv->adapter, ERROR,
>                                     "Wrong TLV id=0x%x\n", tlv_type);
> @@ -929,6 +937,14 @@ void mwifiex_11n_rxba_sync_event(struct mwifiex_private *priv,
>
>                 tlv_seq_num = le16_to_cpu(tlv_rxba->seq_num);
>                 tlv_bitmap_len = le16_to_cpu(tlv_rxba->bitmap_len);
> +               if (size_add(sizeof(*tlv_rxba), tlv_bitmap_len) > tlv_buf_left) {
> +                       mwifiex_dbg(priv->adapter, WARN,
> +                                   "TLV size (%ld) overflows event_buf (%d)\n",
> +                                   size_add(sizeof(*tlv_rxba), tlv_bitmap_len),
> +                                   tlv_buf_left);
> +                       return;
> +               }
> +
>                 mwifiex_dbg(priv->adapter, INFO,
>                             "%pM tid=%d seq_num=%d bitmap_len=%d\n",
>                             tlv_rxba->mac, tlv_rxba->tid, tlv_seq_num,
> --
> 2.34.1
>

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH 3/3] wifi: mwifiex: Sanity check tlv_len and tlv_bitmap_len
  2023-08-23 22:33 ` [PATCH 3/3] wifi: mwifiex: Sanity check tlv_len and tlv_bitmap_len Gustavo A. R. Silva
  2023-08-23 22:38   ` Justin Stitt
@ 2023-08-24  1:07   ` kernel test robot
  1 sibling, 0 replies; 8+ messages in thread
From: kernel test robot @ 2023-08-24  1:07 UTC (permalink / raw)
  To: Gustavo A. R. Silva, Brian Norris, Kalle Valo, Amitkumar Karwar,
	Xinming Hu, Dan Williams
  Cc: oe-kbuild-all, linux-wireless, linux-kernel, Gustavo A. R. Silva,
	linux-hardening

Hi Gustavo,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linus/master]
[also build test WARNING on v6.5-rc7 next-20230823]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Gustavo-A-R-Silva/wifi-mwifiex-Fix-tlv_buf_left-calculation/20230824-063517
base:   linus/master
patch link:    https://lore.kernel.org/r/587423b0737108effe82aefed4407daca39e9a51.1692829410.git.gustavoars%40kernel.org
patch subject: [PATCH 3/3] wifi: mwifiex: Sanity check tlv_len and tlv_bitmap_len
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20230824/202308240844.leyoOwdG-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 13.2.0
reproduce: (https://download.01.org/0day-ci/archive/20230824/202308240844.leyoOwdG-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308240844.leyoOwdG-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c:12:
   drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c: In function 'mwifiex_11n_rxba_sync_event':
>> drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c:926:37: warning: format '%ld' expects argument of type 'long int', but argument 4 has type 'size_t' {aka 'unsigned int'} [-Wformat=]
     926 |                                     "TLV size (%ld) overflows event_buf (%d)\n",
         |                                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     927 |                                     size_add(sizeof(tlv_rxba->header), tlv_len),
         |                                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         |                                     |
         |                                     size_t {aka unsigned int}
   drivers/net/wireless/marvell/mwifiex/main.h:199:51: note: in definition of macro 'mwifiex_dbg'
     199 |         _mwifiex_dbg(adapter, MWIFIEX_DBG_##mask, fmt, ##__VA_ARGS__)
         |                                                   ^~~
   drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c:926:50: note: format string is defined here
     926 |                                     "TLV size (%ld) overflows event_buf (%d)\n",
         |                                                ~~^
         |                                                  |
         |                                                  long int
         |                                                %d
   drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c:942:37: warning: format '%ld' expects argument of type 'long int', but argument 4 has type 'size_t' {aka 'unsigned int'} [-Wformat=]
     942 |                                     "TLV size (%ld) overflows event_buf (%d)\n",
         |                                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     943 |                                     size_add(sizeof(*tlv_rxba), tlv_bitmap_len),
         |                                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         |                                     |
         |                                     size_t {aka unsigned int}
   drivers/net/wireless/marvell/mwifiex/main.h:199:51: note: in definition of macro 'mwifiex_dbg'
     199 |         _mwifiex_dbg(adapter, MWIFIEX_DBG_##mask, fmt, ##__VA_ARGS__)
         |                                                   ^~~
   drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c:942:50: note: format string is defined here
     942 |                                     "TLV size (%ld) overflows event_buf (%d)\n",
         |                                                ~~^
         |                                                  |
         |                                                  long int
         |                                                %d


vim +926 drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c

   904	
   905	/* This function handles rxba_sync event
   906	 */
   907	void mwifiex_11n_rxba_sync_event(struct mwifiex_private *priv,
   908					 u8 *event_buf, u16 len)
   909	{
   910		struct mwifiex_ie_types_rxba_sync *tlv_rxba = (void *)event_buf;
   911		u16 tlv_type, tlv_len;
   912		struct mwifiex_rx_reorder_tbl *rx_reor_tbl_ptr;
   913		u8 i, j;
   914		u16 seq_num, tlv_seq_num, tlv_bitmap_len;
   915		int tlv_buf_left = len;
   916		int ret;
   917		u8 *tmp;
   918	
   919		mwifiex_dbg_dump(priv->adapter, EVT_D, "RXBA_SYNC event:",
   920				 event_buf, len);
   921		while (tlv_buf_left > sizeof(*tlv_rxba)) {
   922			tlv_type = le16_to_cpu(tlv_rxba->header.type);
   923			tlv_len  = le16_to_cpu(tlv_rxba->header.len);
   924			if (size_add(sizeof(tlv_rxba->header), tlv_len) > tlv_buf_left) {
   925				mwifiex_dbg(priv->adapter, WARN,
 > 926					    "TLV size (%ld) overflows event_buf (%d)\n",

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2023-08-24  1:07 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-08-23 22:29 [PATCH 0/3] wifi: mwifiex: Fix tlv_buf_left calculation and replace one-element array Gustavo A. R. Silva
2023-08-23 22:30 ` [PATCH 1/3] wifi: mwifiex: Fix tlv_buf_left calculation Gustavo A. R. Silva
2023-08-23 22:37   ` Justin Stitt
2023-08-23 22:32 ` [PATCH 2/3] wifi: mwifiex: Replace one-element array with flexible-array member in struct mwifiex_ie_types_rxba_sync Gustavo A. R. Silva
2023-08-23 22:38   ` Justin Stitt
2023-08-23 22:33 ` [PATCH 3/3] wifi: mwifiex: Sanity check tlv_len and tlv_bitmap_len Gustavo A. R. Silva
2023-08-23 22:38   ` Justin Stitt
2023-08-24  1:07   ` kernel test robot

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