wifi: rtw89: coex: Annotate struct rtw89_btc_btf_set_slot_table with __counted_by

PATCH In review Kees Cook 3 participants 5 messages Oct 6, 2023 – Oct 11, 2023 Realtek wireless driver (rtw89)

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Kees Cook

author

2023-10-06 20:17 UTC #0 lore raw

PATCH 1/1 wifi: rtw89: coex: Annotate struct rtw89_btc_btf_set_slot_table with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).

As found with Coccinelle[1], add __counted_by for struct rtw89_btc_btf_set_slot_table.

Cc Ping-Ke Shih <[email protected]>

Cc Kalle Valo <[email protected]>

Cc "Gustavo A. R. Silva" <[email protected]>

Cc [email protected]

Link https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]

Signed-off-by Kees Cook <[email protected]>

---
 drivers/net/wireless/realtek/rtw89/coex.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

drivers/net/wireless/realtek/rtw89/coex.c +1 -1

index 4ba8b3df70ae..d66a1152c3f5 100644
@@ -237,7 +237,7 @@ struct rtw89_btc_btf_set_report {
 struct rtw89_btc_btf_set_slot_table {
 	u8 fver;
 	u8 tbl_num;
-	u8 buf[];
+	u8 buf[] __counted_by(tbl_num);
 } __packed;
 
 struct rtw89_btc_btf_set_mon_reg {

Signature · 1 line

2.34.1

Gustavo A. R. Silva

Reviewed-by on v1 1/1

2023-10-06 23:03 UTC #1 lore raw

Quoted 9 lines · Kees Cook

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).
As found with Coccinelle[1], add __counted_by for struct rtw89_btc_btf_set_slot_table.

Quoted 7 lines

Cc Ping-Ke Shih <[email protected]>
Cc Kalle Valo <[email protected]>
Cc "Gustavo A. R. Silva" <[email protected]>
Cc [email protected]
Cc [email protected]
Link https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by Kees Cook <[email protected]>

Reviewed-by Gustavo A. R. Silva <[email protected]>

Thanks!

Signature · 1 line

Gustavo

Quoted 17 lines

---
  drivers/net/wireless/realtek/rtw89/coex.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

drivers/net/wireless/realtek/rtw89/coex.c +1 -1

index 4ba8b3df70ae..d66a1152c3f5 100644
@@ -237,7 +237,7 @@ struct rtw89_btc_btf_set_report {
  struct rtw89_btc_btf_set_slot_table {
  	u8 fver;
  	u8 tbl_num;
-	u8 buf[];
+	u8 buf[] __counted_by(tbl_num);
  } __packed;
 
  struct rtw89_btc_btf_set_mon_reg {

Ping-Ke Shih

maintainer

2023-10-07 01:21 UTC #2 lore raw

In reply to Kees Cook

Quoted 26 lines · Kees Cook

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).
As found with Coccinelle[1], add __counted_by for struct rtw89_btc_btf_set_slot_table.
Cc Ping-Ke Shih <[email protected]>
Cc Kalle Valo <[email protected]>
Cc "Gustavo A. R. Silva" <[email protected]>
Cc [email protected]
Cc [email protected]
Link https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by Kees Cook <[email protected]>
---
 drivers/net/wireless/realtek/rtw89/coex.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/net/wireless/realtek/rtw89/coex.c +0 -0
index 4ba8b3df70ae..d66a1152c3f5 100644

drivers/net/wireless/realtek/rtw89/coex.c struct rtw89_btc_btf_set_report { · line 240

Quoted 5 lines

drivers/net/wireless/realtek/rtw89/coex.c +1 -1

@@ -237,7 +237,7 @@ struct rtw89_btc_btf_set_report {
 struct rtw89_btc_btf_set_slot_table {
        u8 fver;
        u8 tbl_num;
-       u8 buf[];
+       u8 buf[] __counted_by(tbl_num);

This struct isn't defined properly. It should be

struct rtw89_btc_btf_set_slot_table {
	u8 fver;
	u8 tbl_num;
	struct rtw89_btc_fbtc_slot tbl[] __counted_by(tbl_num);
} __packed;

And, we should modify rtw89_btc_fw_set_slots() as well.

Another struct 'rtw89_btc_btf_set_mon_reg' has similar problem.

So, NACK this patch. I will prepare one or two patches for them next week.

By the way, I have question about __counted_by(). Can I apply it to little/big- endian 'num'? Like

struct foo {
	...
	__le32 num;
	__le32 data[] __counted_by(num);
}

Quoted 6 lines

drivers/net/wireless/realtek/rtw89/coex.c +0 -1
 } __packed;
 
 struct rtw89_btc_btf_set_mon_reg {
--
2.34.1

Kees Cook

author

2023-10-09 16:56 UTC #3 lore raw

Quoted 41 lines · Ping-Ke Shih

Quoted 26 lines · Kees Cook
Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).
As found with Coccinelle[1], add __counted_by for struct rtw89_btc_btf_set_slot_table.
Cc Ping-Ke Shih <[email protected]>
Cc Kalle Valo <[email protected]>
Cc "Gustavo A. R. Silva" <[email protected]>
Cc [email protected]
Cc [email protected]
Link https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by Kees Cook <[email protected]>
---
 drivers/net/wireless/realtek/rtw89/coex.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/net/wireless/realtek/rtw89/coex.c +0 -0
index 4ba8b3df70ae..d66a1152c3f5 100644
drivers/net/wireless/realtek/rtw89/coex.c struct rtw89_btc_btf_set_report { · line 240
Quoted 5 lines
drivers/net/wireless/realtek/rtw89/coex.c +1 -1
@@ -237,7 +237,7 @@ struct rtw89_btc_btf_set_report {
 struct rtw89_btc_btf_set_slot_table {
        u8 fver;
        u8 tbl_num;
-       u8 buf[];
+       u8 buf[] __counted_by(tbl_num);
This struct isn't defined properly. It should be
struct rtw89_btc_btf_set_slot_table {
	u8 fver;
	u8 tbl_num;
	struct rtw89_btc_fbtc_slot tbl[] __counted_by(tbl_num);
} __packed;

Quoted 5 lines

And, we should modify rtw89_btc_fw_set_slots() as well.
Another struct 'rtw89_btc_btf_set_mon_reg' has similar problem.
So, NACK this patch. I will prepare one or two patches for them next week.

Ah-ha; thank you!

Quoted 8 lines

By the way, I have question about __counted_by(). Can I apply it to little/big- endian 'num'? Like
struct foo {
	...
	__le32 num;
	__le32 data[] __counted_by(num);
}

Unfortunately not yet. I hope to see it extended in the future to allow for arbitrary expressions. For this first step, it only handles native sizes.

Signature · 1 line

Kees Cook

Ping-Ke Shih

maintainer

2023-10-11 06:42 UTC #4 lore raw

Hi Kees,

Quoted 9 lines

-----Original Message-----
From: Kees Cook <[email protected]>
Sent: Tuesday, October 10, 2023 12:56 AM
To: Ping-Ke Shih <[email protected]>
Cc: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Subject: Re: [PATCH] wifi: rtw89: coex: Annotate struct rtw89_btc_btf_set_slot_table with __counted_by

Quoted 6 lines

Quoted 3 lines · Ping-Ke Shih
On Fri, 2023-10-06 at 13:17 -0700, Kees Cook wrote:
So, NACK this patch. I will prepare one or two patches for them next week.
Ah-ha; thank you!

I have sent two patches [1]. Please help to review and Cc people if needed.

[1] https://lore.kernel.org/linux-wireless/[email protected]/T/#t