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 <gustavoars@xxxxxxxxxx>
---
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
