From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0AC311170E for ; Mon, 11 Sep 2023 14:00:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 84882C433C8; Mon, 11 Sep 2023 14:00:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694440816; bh=B3mGKoJXjsHx/Vyoniy5lOqNvAvKiDRlVVns+mXr9ew=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UtOkEdfiAtIGiPWdXDM+r/cbiNcsjDFb+uxYH4ocN6ITkcHBTHsfGR0g4ar1EHUd5 8s5SnX1MQ8uos5n+kJI2ZOT4OXMeljlJcEfe1Hu+cNPFFHaNp5od+r1s0bx4wa90nk Wx81AOKWtXgUHiRMHbZWbVZP6W1+GqpLnml6BKo0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Arnd Bergmann , Kees Cook , Johannes Berg , Sasha Levin Subject: [PATCH 6.5 168/739] mac80211: make ieee80211_tx_info padding explicit Date: Mon, 11 Sep 2023 15:39:27 +0200 Message-ID: <20230911134655.870145614@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230911134650.921299741@linuxfoundation.org> References: <20230911134650.921299741@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnd Bergmann [ Upstream commit a7a2ef0c4b3efbd7d6f3fabd87dbbc0b3f2de5af ] While looking at a bug, I got rather confused by the layout of the 'status' field in ieee80211_tx_info. Apparently, the intention is that status_driver_data[] is used for driver specific data, and fills up the size of the union to 40 bytes, just like the other ones. This is indeed what actually happens, but only because of the combination of two mistakes: - "void *status_driver_data[18 / sizeof(void *)];" is intended to be 18 bytes long but is actually two bytes shorter because of rounding-down in the division, to a multiple of the pointer size (4 bytes or 8 bytes). - The other fields combined are intended to be 22 bytes long, but are actually 24 bytes because of padding in front of the unaligned tx_time member, and in front of the pointer array. The two mistakes cancel out. so the size ends up fine, but it seems more helpful to make this explicit, by having a multiple of 8 bytes in the size calculation and explicitly describing the padding. Fixes: ea5907db2a9cc ("mac80211: fix struct ieee80211_tx_info size") Fixes: 02219b3abca59 ("mac80211: add WMM admission control support") Signed-off-by: Arnd Bergmann Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20230623152443.2296825-2-arnd@kernel.org Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- include/net/mac80211.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 2a55ae932c568..ad41581384d9f 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -1192,9 +1192,11 @@ struct ieee80211_tx_info { u8 ampdu_ack_len; u8 ampdu_len; u8 antenna; + u8 pad; u16 tx_time; u8 flags; - void *status_driver_data[18 / sizeof(void *)]; + u8 pad2; + void *status_driver_data[16 / sizeof(void *)]; } status; struct { struct ieee80211_tx_rate driver_rates[ -- 2.40.1