This series aims to replace one-element arrays with flexible-array
members in multiple structures in drivers/net/wireless/ath/ath6kl/wmi.h
There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].
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().
These issues were found with the help of Coccinelle and audited and fixed,
manually.
[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79
Gustavo A. R. Silva (6):
ath6kl: wmi: Replace one-element array with flexible-array member in
struct wmi_begin_scan_cmd
ath6kl: wmi: Replace one-element array with flexible-array member in
struct wmi_start_scan_cmd
ath6kl: wmi: Replace one-element array with flexible-array member in
struct wmi_channel_list_reply
ath6kl: wmi: Replace one-element array with flexible-array member in
struct wmi_connect_event
ath6kl: wmi: Replace one-element array with flexible-array member in
struct wmi_disconnect_event
ath6kl: wmi: Replace one-element array with flexible-array member in
struct wmi_aplist_event
drivers/net/wireless/ath/ath6kl/wmi.c | 30 +++++++--------------------
drivers/net/wireless/ath/ath6kl/wmi.h | 12 +++++------
2 files changed, 14 insertions(+), 28 deletions(-)
--
2.27.0
Replace one-element array with flexible-array member in struct
wmi_start_scan_cmd. Also, make use of the struct_size() helper.
This issue was found with the help of Coccinelle and audited and fixed,
manually.
Link: https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/net/wireless/ath/ath6kl/wmi.c | 8 +-------
drivers/net/wireless/ath/ath6kl/wmi.h | 2 +-
2 files changed, 2 insertions(+), 8 deletions(-)
diff --git a/drivers/net/wireless/ath/ath6kl/wmi.c b/drivers/net/wireless/ath/ath6kl/wmi.c
index e1c950014f3e..bdfc057c5a82 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.c
+++ b/drivers/net/wireless/ath/ath6kl/wmi.c
@@ -1959,21 +1959,15 @@ static int ath6kl_wmi_startscan_cmd(struct wmi *wmi, u8 if_idx,
{
struct sk_buff *skb;
struct wmi_start_scan_cmd *sc;
- s8 size;
int i, ret;
- size = sizeof(struct wmi_start_scan_cmd);
-
if ((scan_type != WMI_LONG_SCAN) && (scan_type != WMI_SHORT_SCAN))
return -EINVAL;
if (num_chan > WMI_MAX_CHANNELS)
return -EINVAL;
- if (num_chan)
- size += sizeof(u16) * (num_chan - 1);
-
- skb = ath6kl_wmi_get_new_buf(size);
+ skb = ath6kl_wmi_get_new_buf(struct_size(sc, ch_list, num_chan));
if (!skb)
return -ENOMEM;
diff --git a/drivers/net/wireless/ath/ath6kl/wmi.h b/drivers/net/wireless/ath/ath6kl/wmi.h
index 322539ed9c12..9e168752bec2 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.h
+++ b/drivers/net/wireless/ath/ath6kl/wmi.h
@@ -889,7 +889,7 @@ struct wmi_start_scan_cmd {
u8 num_ch;
/* channels in Mhz */
- __le16 ch_list[1];
+ __le16 ch_list[];
} __packed;
/*
--
2.27.0
Replace one-element array with flexible-array member in struct
wmi_begin_scan_cmd. Also, make use of the struct_size() helper.
This issue was found with the help of Coccinelle and audited and fixed,
manually.
Link: https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/net/wireless/ath/ath6kl/wmi.c | 9 ++-------
drivers/net/wireless/ath/ath6kl/wmi.h | 2 +-
2 files changed, 3 insertions(+), 8 deletions(-)
diff --git a/drivers/net/wireless/ath/ath6kl/wmi.c b/drivers/net/wireless/ath/ath6kl/wmi.c
index bd1ef6334997..e1c950014f3e 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.c
+++ b/drivers/net/wireless/ath/ath6kl/wmi.c
@@ -2008,7 +2008,7 @@ int ath6kl_wmi_beginscan_cmd(struct wmi *wmi, u8 if_idx,
struct ieee80211_supported_band *sband;
struct sk_buff *skb;
struct wmi_begin_scan_cmd *sc;
- s8 size, *supp_rates;
+ s8 *supp_rates;
int i, band, ret;
struct ath6kl *ar = wmi->parent_dev;
int num_rates;
@@ -2023,18 +2023,13 @@ int ath6kl_wmi_beginscan_cmd(struct wmi *wmi, u8 if_idx,
num_chan, ch_list);
}
- size = sizeof(struct wmi_begin_scan_cmd);
-
if ((scan_type != WMI_LONG_SCAN) && (scan_type != WMI_SHORT_SCAN))
return -EINVAL;
if (num_chan > WMI_MAX_CHANNELS)
return -EINVAL;
- if (num_chan)
- size += sizeof(u16) * (num_chan - 1);
-
- skb = ath6kl_wmi_get_new_buf(size);
+ skb = ath6kl_wmi_get_new_buf(struct_size(sc, ch_list, num_chan));
if (!skb)
return -ENOMEM;
diff --git a/drivers/net/wireless/ath/ath6kl/wmi.h b/drivers/net/wireless/ath/ath6kl/wmi.h
index 784940ba4c90..322539ed9c12 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.h
+++ b/drivers/net/wireless/ath/ath6kl/wmi.h
@@ -863,7 +863,7 @@ struct wmi_begin_scan_cmd {
u8 num_ch;
/* channels in Mhz */
- __le16 ch_list[1];
+ __le16 ch_list[];
} __packed;
/* wmi_start_scan_cmd is to be deprecated. Use
--
2.27.0
Replace one-element array with flexible-array member in struct
wmi_channel_list_reply.
It's also worth noting that due to the flexible array transformation,
the size of struct wmi_channel_list_reply changed, see below.
Before flex-array transformation:
struct wmi_channel_list_reply {
u8 reserved; /* 0 1 */
u8 num_ch; /* 1 1 */
__le16 ch_list[1]; /* 2 2 */
/* size: 4, cachelines: 1, members: 3 */
/* last cacheline: 4 bytes */
};
After flex-array transformation:
struct wmi_channel_list_reply {
u8 reserved; /* 0 1 */
u8 num_ch; /* 1 1 */
__le16 ch_list[]; /* 2 0 */
/* size: 2, cachelines: 1, members: 3 */
/* last cacheline: 2 bytes */
};
So, the following change preserves the logic that if _len_ is at least
4 bytes in size, this is the existence of at least one channel in
ch_list[] is being considered, then the execution jumps to call
ath6kl_wakeup_event(wmi->parent_dev);, otherwise _len_ is 2 bytes or
less and the code returns -EINVAL:
- if (len < sizeof(struct wmi_channel_list_reply))
+ if (len <= sizeof(struct wmi_channel_list_reply))
This issue was found with the help of Coccinelle and audited and fixed,
manually.
Link: https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
Hi!
It'd be great if someone can confirm or comment on the following
changes described in the changelog text:
- if (len < sizeof(struct wmi_channel_list_reply))
+ if (len <= sizeof(struct wmi_channel_list_reply))
Thanks
drivers/net/wireless/ath/ath6kl/wmi.c | 2 +-
drivers/net/wireless/ath/ath6kl/wmi.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/ath/ath6kl/wmi.c b/drivers/net/wireless/ath/ath6kl/wmi.c
index bdfc057c5a82..049d75f31f3c 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.c
+++ b/drivers/net/wireless/ath/ath6kl/wmi.c
@@ -1240,7 +1240,7 @@ static int ath6kl_wmi_ratemask_reply_rx(struct wmi *wmi, u8 *datap, int len)
static int ath6kl_wmi_ch_list_reply_rx(struct wmi *wmi, u8 *datap, int len)
{
- if (len < sizeof(struct wmi_channel_list_reply))
+ if (len <= sizeof(struct wmi_channel_list_reply))
return -EINVAL;
ath6kl_wakeup_event(wmi->parent_dev);
diff --git a/drivers/net/wireless/ath/ath6kl/wmi.h b/drivers/net/wireless/ath/ath6kl/wmi.h
index 9e168752bec2..432e4f428a4a 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.h
+++ b/drivers/net/wireless/ath/ath6kl/wmi.h
@@ -1373,7 +1373,7 @@ struct wmi_channel_list_reply {
u8 num_ch;
/* channel in Mhz */
- __le16 ch_list[1];
+ __le16 ch_list[];
} __packed;
/* List of Events (target to host) */
--
2.27.0
On 2/22/2022 6:38 PM, Gustavo A. R. Silva wrote:
> Replace one-element array with flexible-array member in struct
> wmi_begin_scan_cmd. Also, make use of the struct_size() helper.
>
> This issue was found with the help of Coccinelle and audited and fixed,
> manually.
>
> Link: https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
> Link: https://github.com/KSPP/linux/issues/79
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> drivers/net/wireless/ath/ath6kl/wmi.c | 9 ++-------
> drivers/net/wireless/ath/ath6kl/wmi.h | 2 +-
> 2 files changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath6kl/wmi.c b/drivers/net/wireless/ath/ath6kl/wmi.c
> index bd1ef6334997..e1c950014f3e 100644
> --- a/drivers/net/wireless/ath/ath6kl/wmi.c
> +++ b/drivers/net/wireless/ath/ath6kl/wmi.c
> @@ -2008,7 +2008,7 @@ int ath6kl_wmi_beginscan_cmd(struct wmi *wmi, u8 if_idx,
> struct ieee80211_supported_band *sband;
> struct sk_buff *skb;
> struct wmi_begin_scan_cmd *sc;
> - s8 size, *supp_rates;
> + s8 *supp_rates;
> int i, band, ret;
> struct ath6kl *ar = wmi->parent_dev;
> int num_rates;
> @@ -2023,18 +2023,13 @@ int ath6kl_wmi_beginscan_cmd(struct wmi *wmi, u8 if_idx,
> num_chan, ch_list);
> }
>
> - size = sizeof(struct wmi_begin_scan_cmd);
> -
> if ((scan_type != WMI_LONG_SCAN) && (scan_type != WMI_SHORT_SCAN))
> return -EINVAL;
>
> if (num_chan > WMI_MAX_CHANNELS)
> return -EINVAL;
>
> - if (num_chan)
> - size += sizeof(u16) * (num_chan - 1);
> -
> - skb = ath6kl_wmi_get_new_buf(size);
> + skb = ath6kl_wmi_get_new_buf(struct_size(sc, ch_list, num_chan));
> if (!skb)
> return -ENOMEM;
>
> diff --git a/drivers/net/wireless/ath/ath6kl/wmi.h b/drivers/net/wireless/ath/ath6kl/wmi.h
> index 784940ba4c90..322539ed9c12 100644
> --- a/drivers/net/wireless/ath/ath6kl/wmi.h
> +++ b/drivers/net/wireless/ath/ath6kl/wmi.h
> @@ -863,7 +863,7 @@ struct wmi_begin_scan_cmd {
> u8 num_ch;
>
> /* channels in Mhz */
> - __le16 ch_list[1];
> + __le16 ch_list[];
> } __packed;
>
> /* wmi_start_scan_cmd is to be deprecated. Use
Reviewed-by: Jeff Johnson <[email protected]>