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 21412223711; Thu, 12 Dec 2024 17:49:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734025786; cv=none; b=l8e+bL98y8L8A7cJC7+AB4kh+tDVc1GDQSgG/aXbck8ySiCdidqxFcMQyOFErEW+ay4RSTDAJ/DlNPX6wh6gmoaOjLlFlU0CqLRa4D0yq2MuHGJhDDO+8bq1H0Y4D1ZOc4ufc75i5W3D0UYAPdRPHga/oI8vuY9udbxVc3KjRbc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734025786; c=relaxed/simple; bh=PTKsp6gP/Zhq1lvXKtBLlaFwWXHgL1tWuZgHRWWniaU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AVJzaYP9esPEp8HjmYSL1rRSwqYJ41qWDBcURk7y9IrDXkgp+sZH4w4GM4WrXAEOC+m1kbTMMXRiKn7XHs8aWG+9rEN63sibP1wN50ED2xkD/6o+LawntWBisOd94/IeDeXKogtT/LDJH6VOjkHv04pZCIuwO13oF4ThEMDUgxY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Km0eHuw1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Km0eHuw1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9C646C4CECE; Thu, 12 Dec 2024 17:49:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1734025786; bh=PTKsp6gP/Zhq1lvXKtBLlaFwWXHgL1tWuZgHRWWniaU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Km0eHuw1zB3nDUp00bUlnjWsX325u/mpKWi9o6dImQixTF/Sw65z4Ysi7C3vay+hh w2JVyyJ3qE+UZ69fcNHxsZWPDa4rmN762MVVu/0Ssb/zXaeW3ZOwCN2c4SOJopZ6xN fDY0e8vUA8jb/+jA5U6ZsrNE00SMbvIF+V1o7k88= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Norbert van Bolhuis , Kalle Valo , Sasha Levin Subject: [PATCH 5.4 288/321] wifi: brcmfmac: Fix oops due to NULL pointer dereference in brcmf_sdiod_sglist_rw() Date: Thu, 12 Dec 2024 16:03:26 +0100 Message-ID: <20241212144241.358386404@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241212144229.291682835@linuxfoundation.org> References: <20241212144229.291682835@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Norbert van Bolhuis [ Upstream commit 857282b819cbaa0675aaab1e7542e2c0579f52d7 ] This patch fixes a NULL pointer dereference bug in brcmfmac that occurs when a high 'sd_sgentry_align' value applies (e.g. 512) and a lot of queued SKBs are sent from the pkt queue. The problem is the number of entries in the pre-allocated sgtable, it is nents = max(rxglom_size, txglom_size) + max(rxglom_size, txglom_size) >> 4 + 1. Given the default [rt]xglom_size=32 it's actually 35 which is too small. Worst case, the pkt queue can end up with 64 SKBs. This occurs when a new SKB is added for each original SKB if tailroom isn't enough to hold tail_pad. At least one sg entry is needed for each SKB. So, eventually the "skb_queue_walk loop" in brcmf_sdiod_sglist_rw may run out of sg entries. This makes sg_next return NULL and this causes the oops. The patch sets nents to max(rxglom_size, txglom_size) * 2 to be able handle the worst-case. Btw. this requires only 64-35=29 * 16 (or 20 if CONFIG_NEED_SG_DMA_LENGTH) = 464 additional bytes of memory. Signed-off-by: Norbert van Bolhuis Signed-off-by: Kalle Valo Link: https://patch.msgid.link/20241107132903.13513-1-nvbolhuis@gmail.com Signed-off-by: Sasha Levin --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c index c492d2d2db1df..32ac1fa5bdecf 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c @@ -770,7 +770,7 @@ void brcmf_sdiod_sgtable_alloc(struct brcmf_sdio_dev *sdiodev) nents = max_t(uint, BRCMF_DEFAULT_RXGLOM_SIZE, sdiodev->settings->bus.sdio.txglomsz); - nents += (nents >> 4) + 1; + nents *= 2; WARN_ON(nents > sdiodev->max_segment_count); -- 2.43.0