Commit 4fed494a authored Sep 14, 2023 by Juerg Haefliger Committed by Kalle Valo Sep 18, 2023

wifi: brcmfmac: Replace 1-element arrays with flexible arrays



Since commit 2d47c695 ("ubsan: Tighten UBSAN_BOUNDS on GCC"),
UBSAN_BOUNDS no longer pretends 1-element arrays are unbounded. Walking
'element' and 'channel_list' will trigger warnings, so make them proper
flexible arrays.

False positive warnings were:

  UBSAN: array-index-out-of-bounds in drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c:6984:20
  index 1 is out of range for type '__le32 [1]'

  UBSAN: array-index-out-of-bounds in drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c:1126:27
  index 1 is out of range for type '__le16 [1]'

for these lines of code:

  6884  ch.chspec = (u16)le32_to_cpu(list->element[i]);

  1126  params_le->channel_list[i] = cpu_to_le16(chanspec);

Cc: stable@vger.kernel.org # 6.5+
Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230914070227.12028-1-juerg.haefliger@canonical.com

parent aef7a030

drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h

+7 −2

Original line number	Diff line number	Diff line
		@@ -442,7 +442,12 @@ struct brcmf_scan_params_v2_le {
		* fixed parameter portion is assumed, otherwise
		* ssid in the fixed portion is ignored
		*/
		__le16 channel_list[1]; /* list of chanspecs */
		union {
		__le16 padding; /* Reserve space for at least 1 entry for abort
		* which uses an on stack brcmf_scan_params_v2_le
		*/
		DECLARE_FLEX_ARRAY(__le16, channel_list); /* chanspecs */
		};
		};

		struct brcmf_scan_results {
		@@ -702,7 +707,7 @@ struct brcmf_sta_info_le {

		struct brcmf_chanspec_list {
		__le32 count; /* # of entries */
		__le32 element[1]; /* variable length uint32 list */
		__le32 element[]; /* variable length uint32 list */
		};

		/*