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 AAB7150B414; Wed, 30 Sep 2026 16:01:34 +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=1790784100; cv=none; b=kltTZaxC/hPqcPeT2y6rUp3sie/OLMYhj4XcR6Bch8xAgDrrO8PbmgPHgG6B+3yLv/5gzNvJXRLZIsLDHqCmc66T6qR/4kO6TzFp0Njb07IEJ76+YULFF6FH1/1TG/10tae1pvd23/7RNiFNbeDJ917o8mdzHgAlLzYcbda72wg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790784100; c=relaxed/simple; bh=RG8voCN0oEtmvEFJJPlETsUuJyEZuIskZXnKYaPfMhY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kjeDefpffyjb/sJMotU1dpm1OmO0sCADNbmjyCE+KrR6wvCM5UwNIbUyAxH+ikvztgb0y0K9NoBN39tpTIAhMqCnJpDgoA8Y7FX1tgjjwI4ILAUOlRkNUCNS63Yyc2COCMtIguRFUXV/sQofxgWcmRdnYF602QB1YkM1F/vtbb4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GnowHgYc; 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="GnowHgYc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB2FA1F000FF; Wed, 30 Sep 2026 16:01:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790784091; bh=kHt5G8iupVzMjLOu4+xdlNotx1NXHggQuDrkWJTujmg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=GnowHgYcFdPWT43TclpFqmb4EaNSIp+rS6CWiEvwU+pLfdM6uzAnuWoGS814Ze5eV 4SpjoSEXK38c7Hb7dnT2YnZ7k5Oq/nnHFO9bh83j3qor31B+QfQKvSayC3KNZLllQ2 As7WbvnKQHWA+doMP4xxx9qI/IcAL5iUdjJfuPzA= 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 6.1 034/982] mmc: davinci: avoid NULL deref of host->data in IRQ handler Date: Wed, 30 Sep 2026 17:12:50 +0200 Message-ID: <20260930152417.527628495@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152416.775402466@linuxfoundation.org> References: <20260930152416.775402466@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 6.1-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 e89a97b415154..b744651f3b625 100644 --- a/drivers/mmc/host/davinci_mmc.c +++ b/drivers/mmc/host/davinci_mmc.c @@ -934,7 +934,7 @@ 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; @@ -946,7 +946,7 @@ 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