From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 1741A3B47DF; Tue, 21 Jul 2026 20:39:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784666344; cv=none; b=Gyf5UJS0P8j02CnJwl2Px/VNiaVAmTv+ZpBq0OVZpDagi8hk7y/MGjcTEyuyqjxbzi/IR3tgkHNjby+EjaS3j00ckNLXMjR1qM9g8AxkCSYsDTr+0y7xOlQ+gM96Xbt+nhjdlyvkCZgF1MtSIDdmmx2AioCYQOxVzsvV26R276M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784666344; c=relaxed/simple; bh=d4tMD0Ev7ke3OLnAJxDzJA2527Ro9LqPTaBZ0axHQ6s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TzQqVmoDl/yvPdovoX6UzSfyks4jO7Im89yu4tePdLwBBAHsQltY4SPnarrfkYVlGWs4KjeXHN6x47Ffl7OESirRfguhmV/PiGXMAd4Lyddy/MvzpxWmoSLe9dBOiirFf8gn/fTSNxd53eTSlbsyFrN6eSr1mU2HJ49ZeaBFLw0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nbnjP5gU; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nbnjP5gU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 779ED1F000E9; Tue, 21 Jul 2026 20:39:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784666343; bh=/4ggSxK43r4OdKSdPNOG7OYBpvAzdsubE/gLCWk7K0k=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nbnjP5gUpHp+z6YPd6XAOomnhpDc3S/bJPBo8xZkVhAyOJktQW5bqrxfipNCuIPCG 1pSMFgGUinAed3DWkzwoZo9E0WpLAshlZdhPF3/IrpYpcMQrd1F9nYHXfNwKJoOqri WHBFPfDTKEc+khDL8t42QTYFPunyXAh3LRaR94+w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dan Carpenter , Alexandru Hossu , Sasha Levin Subject: [PATCH 6.6 0604/1266] staging: nvec: fix use-after-free in nvec_rx_completed() Date: Tue, 21 Jul 2026 17:17:21 +0200 Message-ID: <20260721152455.379181159@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152441.786066624@linuxfoundation.org> References: <20260721152441.786066624@linuxfoundation.org> User-Agent: quilt/0.69 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexandru Hossu [ Upstream commit 26813881181deb3a32fbb59eadb2599cbe8423f6 ] In nvec_rx_completed(), when an incomplete RX transfer is detected, nvec_msg_free() is called to return the message back to the pool by clearing its 'used' atomic flag. Immediately after this, the code accesses nvec->rx->data[0] to check the message type. Since nvec_msg_free() marks the pool slot as available via atomic_set(), any concurrent or subsequent call to nvec_msg_alloc() could claim that same slot and overwrite its data[] array. Reading nvec->rx->data[0] after freeing the message is therefore a use-after-free. Fix this by saving the message type byte before calling nvec_msg_free(), then using the saved value for the battery quirk check. Fixes: d6bdcf2e1019 ("staging: nvec: Add battery quirk to ignore incomplete responses") Reviewed-by: Dan Carpenter Signed-off-by: Alexandru Hossu Link: https://patch.msgid.link/20260427081713.3401874-2-hossu.alexandru@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/staging/nvec/nvec.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/staging/nvec/nvec.c b/drivers/staging/nvec/nvec.c index 2823cacde13093..0ed7266b033eb5 100644 --- a/drivers/staging/nvec/nvec.c +++ b/drivers/staging/nvec/nvec.c @@ -489,6 +489,8 @@ static void nvec_tx_completed(struct nvec_chip *nvec) static void nvec_rx_completed(struct nvec_chip *nvec) { if (nvec->rx->pos != nvec_msg_size(nvec->rx)) { + unsigned char msg_type = nvec->rx->data[0]; + dev_err(nvec->dev, "RX incomplete: Expected %u bytes, got %u\n", (uint)nvec_msg_size(nvec->rx), (uint)nvec->rx->pos); @@ -497,7 +499,7 @@ static void nvec_rx_completed(struct nvec_chip *nvec) nvec->state = 0; /* Battery quirk - Often incomplete, and likes to crash */ - if (nvec->rx->data[0] == NVEC_BAT) + if (msg_type == NVEC_BAT) complete(&nvec->ec_transfer); return; -- 2.53.0