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 C2DBB525A79; Wed, 30 Sep 2026 17:50:47 +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=1790790648; cv=none; b=gTwlX/FKtY1j1A0gf6YEhDoNS6a8jZAMGANRsP83Yf2bF/SBa/TwXfkJ6UhdJe/LCF99pWXJl5TrMdukKX3ZsOjje/ttYDKWLKLkFiK0pfexL4LWinkjEtC89v3L/ECiPvGnNpQLywT05kQD7eosp90vhiqUI0fCUhnoFjDFobo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790790648; c=relaxed/simple; bh=DGA4l/TJMPR4gIt5oWAaP9fVjq8v+LdUkp53+62dcko=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PJCfVYWKTOXIycUoNxwtqjYZLRUddQazl4Wzp/H6ZhIXOqREHTqUuO2h+P3cYPixB9yo0MnfP2yjMU9P9LJsDvrHQhZfG+IRMSOUm6s6/z8fjifZ81jd1yGLRfBykInfaAEKTnzEVuAwDvl005MrExLDCOlTDBNEoe2wjCSUAmc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zuKSys3x; 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="zuKSys3x" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20E911F000FF; Wed, 30 Sep 2026 17:50:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790790647; bh=Q8EFNulZcSHEL3fa4A9RkL4Gk7syL9vFimZ1jqwN8oQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=zuKSys3xYylWs/QJLcs/O3EEw6WMLLBkiPuecP7X6figWWxI/3T7KTD/I09aVW8Ga ILt24arfD1M0rad+KOAHiOxsF/5DVKEZEVSnLehPkWT4A4bB5Rj5rM1m8AUWXGuIlb Xp3hG1ZQ4+HifsMtEp5XmWmoY8kNjHBj+mdSE7GM= 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 5.15 025/752] mmc: davinci: avoid NULL deref of host->data in IRQ handler Date: Wed, 30 Sep 2026 17:18:15 +0200 Message-ID: <20260930152358.696317045@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152358.131179731@linuxfoundation.org> References: <20260930152358.131179731@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 5.15-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 e0175808c3b0d..845604a96bc93 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