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 58DF04F390B; Thu, 17 Sep 2026 16:05:41 +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=1789661142; cv=none; b=aWIBdPmfO+9b9UMwgjSIHcXfGg5iO9jkTG2H4jZCZS+bILVl8hOyuLMh+OfFBTu8SQuIQsgq/nh5GFecBYXIksE6DW8iS2R4TG0mvBPXuVrG1K9AA3fIlhoIOhP507yQdD/WEaciW5a/JA6xetN+/7DEFs4/NBoKtQBDAhm581E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789661142; c=relaxed/simple; bh=j8mwCm4e59vlfbItYASrvulltpW8BsChx0Lmj83ybZk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CwjNiMahuWdu7AnJmMtzhIg/YyOgWYWro0jmG81WGq30TgXGtrz9lyQrJY9Gx1N0kGWAuyu4Hf5zTGMXQDs1bvN2re+WPyg33HVB5xn0QAgLufUS7q48oGgWFpbfW/J/JT5b1dLWahTIzDZcUy8Mz3OoAi/9CCDVZC8D2Q1VueQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GA8RHjMd; 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="GA8RHjMd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 763261F000FF; Thu, 17 Sep 2026 16:05:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789661141; bh=adkehM31YHgMruSZDuU2LWzJ3zdk5JaUN2POMgUMqRk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=GA8RHjMdmhL4hEV3CozBuXoXxtfiGysnUFfgyPRcYQyyYoaGl6VwdQE6oHr/ltEj8 VFRLSpw3SHPK9P7jrnfE4hwFhs9KjeQ2B6dNUox9fm5Td/Cpr0dzyAQYJYYSEh0sGS 7Wu6QGSW1rsFVgicEcc4mYdoOm5thmXkTcfCXBlE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stepan Ionichev , Bartosz Golaszewski , Ulf Hansson , Sasha Levin Subject: [PATCH 6.18 0096/1250] mmc: davinci: avoid NULL deref of host->data in IRQ handler Date: Thu, 17 Sep 2026 15:58:11 +0100 Message-ID: <20260917151554.588999239@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260917151551.901433442@linuxfoundation.org> References: <20260917151551.901433442@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stepan Ionichev [ Upstream commit 4f28846aaf8db9668e338b8987973f8935edff34 ] mmc_davinci_irq() returns early only when both host->cmd and host->data are NULL: if (host->cmd == NULL && host->data == NULL) { ... return IRQ_NONE; } So we may legitimately reach the rest of the handler with host->data == NULL (and therefore data == NULL). The DATDNE branch already guards against this with an explicit "if (data != NULL)" check, but the subsequent TOUTRD ("read data timeout") and CRCWR/CRCRD ("data CRC error") branches dereference data unconditionally: if (qstatus & MMCST0_TOUTRD) { data->error = -ETIMEDOUT; <-- NULL deref ... davinci_abort_data(host, data); } if (qstatus & (MMCST0_CRCWR | MMCST0_CRCRD)) { data->error = -EILSEQ; <-- NULL deref ... } If either bit is set in qstatus while host->data is NULL, the kernel will crash inside the IRQ handler. smatch flags this: drivers/mmc/host/davinci_mmc.c:933 mmc_davinci_irq() error: we previously assumed 'data' could be null (see line 914) Gate both branches on a non-NULL data, matching the existing pattern used by the DATDNE branch. No functional change for callers where data is non-NULL, which is the only case in which these branches did meaningful work before this change. Signed-off-by: Stepan Ionichev Reviewed-by: Bartosz Golaszewski Signed-off-by: Ulf Hansson Signed-off-by: Sasha Levin --- drivers/mmc/host/davinci_mmc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c index 2b7d6d9bcde51..00adc15956fd2 100644 --- a/drivers/mmc/host/davinci_mmc.c +++ b/drivers/mmc/host/davinci_mmc.c @@ -928,7 +928,7 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id) } } - if (qstatus & MMCST0_TOUTRD) { + if (data && (qstatus & MMCST0_TOUTRD)) { /* Read data timeout */ data->error = -ETIMEDOUT; end_transfer = 1; @@ -940,7 +940,7 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id) davinci_abort_data(host, data); } - if (qstatus & (MMCST0_CRCWR | MMCST0_CRCRD)) { + if (data && (qstatus & (MMCST0_CRCWR | MMCST0_CRCRD))) { /* Data CRC error */ data->error = -EILSEQ; end_transfer = 1; -- 2.53.0