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).
Also, -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting ready to enable it globally. So, use the `DEFINE_FLEX()` helper for an on-stack definition of a flexible structure where the size of the flexible-array member is known at compile-time, and refactor the rest of the code, accordingly. So, with these changes, fix the following warning: drivers/net/wireless/ath/wil6210/cfg80211.c:896:43: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] Link: https://github.com/KSPP/linux/issues/202 Signed-off-by: Gustavo A. R. Silva <gustavo...@kernel.org> --- Changes in v2: - Remove redundant memset(). (Jeff Johnson) - Update Subject line: add missing wil6210: (Kalle Valo) v1: - Link: https://lore.kernel.org/linux-hardening/ZgRqjGShTl3y5FFB@neat/ drivers/net/wireless/ath/wil6210/cfg80211.c | 21 +++++++++------------ drivers/net/wireless/ath/wil6210/wmi.h | 2 +- 2 files changed, 10 insertions(+), 13 deletions(-) diff --git a/drivers/net/wireless/ath/wil6210/cfg80211.c b/drivers/net/wireless/ath/wil6210/cfg80211.c index dbe4b3478f03..99f7f4db48fc 100644 --- a/drivers/net/wireless/ath/wil6210/cfg80211.c +++ b/drivers/net/wireless/ath/wil6210/cfg80211.c @@ -892,10 +892,8 @@ static int wil_cfg80211_scan(struct wiphy *wiphy, struct wil6210_priv *wil = wiphy_to_wil(wiphy); struct wireless_dev *wdev = request->wdev; struct wil6210_vif *vif = wdev_to_vif(wil, wdev); - struct { - struct wmi_start_scan_cmd cmd; - u16 chnl[4]; - } __packed cmd; + DEFINE_FLEX(struct wmi_start_scan_cmd, cmd, + channel_list, num_channels, 4); uint i, n; int rc; @@ -977,9 +975,8 @@ static int wil_cfg80211_scan(struct wiphy *wiphy, vif->scan_request = request; mod_timer(&vif->scan_timer, jiffies + WIL6210_SCAN_TO); - memset(&cmd, 0, sizeof(cmd)); - cmd.cmd.scan_type = WMI_ACTIVE_SCAN; - cmd.cmd.num_channels = 0; + cmd->scan_type = WMI_ACTIVE_SCAN; + cmd->num_channels = 0; n = min(request->n_channels, 4U); for (i = 0; i < n; i++) { int ch = request->channels[i]->hw_value; @@ -991,7 +988,8 @@ static int wil_cfg80211_scan(struct wiphy *wiphy, continue; } /* 0-based channel indexes */ - cmd.cmd.channel_list[cmd.cmd.num_channels++].channel = ch - 1; + cmd->num_channels++; + cmd->channel_list[cmd->num_channels - 1].channel = ch - 1; wil_dbg_misc(wil, "Scan for ch %d : %d MHz\n", ch, request->channels[i]->center_freq); } @@ -1007,16 +1005,15 @@ static int wil_cfg80211_scan(struct wiphy *wiphy, if (rc) goto out_restore; - if (wil->discovery_mode && cmd.cmd.scan_type == WMI_ACTIVE_SCAN) { - cmd.cmd.discovery_mode = 1; + if (wil->discovery_mode && cmd->scan_type == WMI_ACTIVE_SCAN) { + cmd->discovery_mode = 1; wil_dbg_misc(wil, "active scan with discovery_mode=1\n"); } if (vif->mid == 0) wil->radio_wdev = wdev; rc = wmi_send(wil, WMI_START_SCAN_CMDID, vif->mid, - &cmd, sizeof(cmd.cmd) + - cmd.cmd.num_channels * sizeof(cmd.cmd.channel_list[0])); + cmd, struct_size(cmd, channel_list, cmd->num_channels)); out_restore: if (rc) { diff --git a/drivers/net/wireless/ath/wil6210/wmi.h b/drivers/net/wireless/ath/wil6210/wmi.h index 71bf2ae27a98..b47606d9068c 100644 --- a/drivers/net/wireless/ath/wil6210/wmi.h +++ b/drivers/net/wireless/ath/wil6210/wmi.h @@ -474,7 +474,7 @@ struct wmi_start_scan_cmd { struct { u8 channel; u8 reserved; - } channel_list[]; + } channel_list[] __counted_by(num_channels); } __packed; #define WMI_MAX_PNO_SSID_NUM (16) -- 2.34.1
