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 E2E2524F25C; Sun, 24 Nov 2024 13:57:49 +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=1732456670; cv=none; b=gZg7fD4AO0hBElNCVrK3GMJHsijxxydgdvk7C+sM2MqdhdDCW7xbgcqpRboC7tFxurbrFzPJpRsWeY7T6Awm6eETwA2JQvNRkFsZL9wD3dTsu41PBLwS/kKzArXENanzZmtQro6+ArfoJiTEA/SbvnIO9+A5J2toP20gHYDDNb8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732456670; c=relaxed/simple; bh=tzdgRpBlFIm+PD09acrAcKWHIEWDJIX3DFIlN8uYEeU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ecHaLwS7UgxdJSVtS/8Zc7FuVz1iGHLcEkGz5EaR3NBqPmx0RsiKIK3E1zHQIFfVUTPqxGhTNXd0MnLfFDyhbYJbnRnKGQ71rFhUPXMYwDTNlmWmkh9WiJiUTzRY5Ybd+0mbwG0Tl79n97bnTPh6UXhoVsTYW5tpH0vVQFcIzWQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=h+m6b6NV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="h+m6b6NV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 08CDDC4CECC; Sun, 24 Nov 2024 13:57:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1732456669; bh=tzdgRpBlFIm+PD09acrAcKWHIEWDJIX3DFIlN8uYEeU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=h+m6b6NVtPmBpGDYdfL1kxUHHtmSVb888UmwYOyqb1L6lPi3hGUhbOv9mYWk/xvch UHM0bNcQKQjq8qNhJ6gEoOnMLVEwSCofbl3n7LdVmBrGKhMK80XSUE8s+96hrLCV5s flIQq8JCxVbRTtSd/fMHHUQM3DJ0dVYuqoOmFk9HDBVDor3oYQbbO3aSF7euvqfGOd +mOn9IotpTmBGe9z1Toyvxl42na1tma5nAPg25zlXYe1/UILE4JWVCtmr8ZLVgyzeo l2irCY5cbVBsF9K2lvEfW8xK76DirD1Mxudf8kSjhnhFjHoddhQVK1OaA6Q2FWtMmk GbFnpQ1STFmlQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Norbert van Bolhuis , Kalle Valo , Sasha Levin , arend.vanspriel@broadcom.com, erick.archer@outlook.com, sebastian.reichel@collabora.com, saikrishnag@marvell.com, krzysztof.kozlowski@linaro.org, jacobe.zang@wesion.com, linux-wireless@vger.kernel.org, brcm80211@lists.linux.dev, brcm80211-dev-list.pdl@broadcom.com Subject: [PATCH AUTOSEL 4.19 18/21] wifi: brcmfmac: Fix oops due to NULL pointer dereference in brcmf_sdiod_sglist_rw() Date: Sun, 24 Nov 2024 08:56:51 -0500 Message-ID: <20241124135709.3351371-18-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241124135709.3351371-1-sashal@kernel.org> References: <20241124135709.3351371-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 4.19.324 Content-Transfer-Encoding: 8bit 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 710dc59c5d34d..532733db4de85 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