From patchwork Tue Sep 17 11:09:42 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Felix Fietkau X-Patchwork-Id: 13806119 X-Patchwork-Delegate: kvalo@adurom.com Received: from nbd.name (nbd.name [46.4.11.11]) (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 DCDED26281 for ; Tue, 17 Sep 2024 11:09:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=46.4.11.11 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726571387; cv=none; b=qBKcRfR4IggyvnBBCNzqBtDpjS6H/NYyVXcdOhG9k7MlyWGXYy6d8XvzYzIeIBD3Lfn1tfi5j98snUMMY649ETcD5OD3rB+S/E111Oe3c9h3TFdFHgq12Iwga0k2Cnf+tNT+HM0NoagSwy/gnnqprih8OfxIWT3u9B4q/qemT3M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726571387; c=relaxed/simple; bh=8uvE+6Hmtx0KskHmFxL6xOlr4QxpO+s1sQKUmLaD680=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=f+qg6/VFKEwBcoGhLNU3qG5LbXJu6bnijnYs/CU1xT3Lq/yCc6842b2qcntgaoDt/VgBxt5ePpKsZabsxfPpZ270oqRFbBUuBBQczrwGlnXRl2x/3m2sehG2TmIIklTha5OXKC2xEfP3oqMuQtyyaWUt9BiVUM7m/S+P/h+aGYE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=nbd.name; spf=none smtp.mailfrom=nbd.name; dkim=pass (1024-bit key) header.d=nbd.name header.i=@nbd.name header.b=MDzQBTaJ; arc=none smtp.client-ip=46.4.11.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=nbd.name Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=nbd.name Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=nbd.name header.i=@nbd.name header.b="MDzQBTaJ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=nbd.name; s=20160729; h=Content-Transfer-Encoding:Content-Type:MIME-Version:Message-ID: Date:Subject:Cc:To:From:Sender:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=TPXlaLC6uzZbFXXfV2+qatVtnIDgeOXYY8Dsppgr0SU=; b=MDzQBTaJqOtwQ01uhi2HDnEXKh agjDTHkR3xAQQY2rXysrAD4PvfrUSIh9K9xBzAnfX6e1tc8Db57OGIKfsq2c/1pJy6r26UbE+Z1aa GK3KMpOkg1Q/0rLFqe8ydKTgIsn/f9PyZDx3ZrXhRcTWzDcskRaRRgs8PzKyQiYEeRLc=; Received: from p4ff1376f.dip0.t-ipconnect.de ([79.241.55.111] helo=localhost.localdomain) by ds12 with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (Exim 4.96) (envelope-from ) id 1sqW5W-00ELRN-2o; Tue, 17 Sep 2024 13:09:42 +0200 From: Felix Fietkau To: linux-wireless@vger.kernel.org Cc: kvalo@kernel.org, =?utf-8?b?TsOtY29sYXMgRi4gUi4gQS4gUHJhZG8=?= , Alper Nebi Yasak Subject: [PATCH] wifi: mt76: do not increase mcu skb refcount if retry is not supported Date: Tue, 17 Sep 2024 13:09:42 +0200 Message-ID: <20240917110942.22077-1-nbd@nbd.name> X-Mailer: git-send-email 2.46.0 Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 If mcu_skb_prepare_msg is not implemented, incrementing skb refcount does not work for mcu message retry. In some cases (e.g. on SDIO), shared skbs can trigger a BUG_ON, crashing the system. Fix this by only incrementing refcount if retry is actually supported. Fixes: 3688c18b65ae ("wifi: mt76: mt7915: retry mcu messages") Reported-by: Nícolas F. R. A. Prado #KernelCI Tested-by: Alper Nebi Yasak Signed-off-by: Felix Fietkau --- drivers/net/wireless/mediatek/mt76/mcu.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/mcu.c b/drivers/net/wireless/mediatek/mt76/mcu.c index 98da82b74094..3353012e8542 100644 --- a/drivers/net/wireless/mediatek/mt76/mcu.c +++ b/drivers/net/wireless/mediatek/mt76/mcu.c @@ -84,13 +84,16 @@ int mt76_mcu_skb_send_and_get_msg(struct mt76_dev *dev, struct sk_buff *skb, mutex_lock(&dev->mcu.mutex); if (dev->mcu_ops->mcu_skb_prepare_msg) { + orig_skb = skb; ret = dev->mcu_ops->mcu_skb_prepare_msg(dev, skb, cmd, &seq); if (ret < 0) goto out; } retry: - orig_skb = skb_get(skb); + /* orig skb might be needed for retry, mcu_skb_send_msg consumes it */ + if (orig_skb) + skb_get(orig_skb); ret = dev->mcu_ops->mcu_skb_send_msg(dev, skb, cmd, &seq); if (ret < 0) goto out; @@ -105,7 +108,7 @@ int mt76_mcu_skb_send_and_get_msg(struct mt76_dev *dev, struct sk_buff *skb, do { skb = mt76_mcu_get_response(dev, expires); if (!skb && !test_bit(MT76_MCU_RESET, &dev->phy.state) && - retry++ < dev->mcu_ops->max_retry) { + orig_skb && retry++ < dev->mcu_ops->max_retry) { dev_err(dev->dev, "Retry message %08x (seq %d)\n", cmd, seq); skb = orig_skb;