From: Alan Mikhak <alan.mikhak@sifive.com>
To: linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org,
linux-pci@vger.kernel.org, maz@kernel.org, tglx@linutronix.de,
gustavo.pimentel@synopsys.com, kishon@ti.com,
paul.walmsley@sifive.com
Cc: Alan Mikhak <alan.mikhak@sifive.com>
Subject: [PATCH] genirq/msi: Check null pointer before copying struct msi_msg
Date: Fri, 17 Apr 2020 11:48:42 -0700 [thread overview]
Message-ID: <1587149322-28104-1-git-send-email-alan.mikhak@sifive.com> (raw)
From: Alan Mikhak <alan.mikhak@sifive.com>
Modify __get_cached_msi_msg() to check both pointers for null before
copying the contents from the struct msi_msg pointer to the pointer
provided by caller.
Without this sanity check, __get_cached_msi_msg() crashes when invoked by
dw_edma_irq_request() in drivers/dma/dw-edma/dw-edma-core.c running on a
Linux-based PCIe endpoint device. MSI interrupt are not received by PCIe
endpoint devices. As a result, irq_get_msi_desc() returns null since there
are no cached struct msi_msg entry on the endpoint side.
Signed-off-by: Alan Mikhak <alan.mikhak@sifive.com>
---
kernel/irq/msi.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index eb95f6106a1e..f39d42ef0d50 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -58,7 +58,8 @@ void free_msi_entry(struct msi_desc *entry)
void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
{
- *msg = entry->msg;
+ if (entry && msg)
+ *msg = entry->msg;
}
void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
--
2.7.4
next reply other threads:[~2020-04-17 18:48 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-17 18:48 Alan Mikhak [this message]
2020-04-18 11:21 ` [PATCH] genirq/msi: Check null pointer before copying struct msi_msg Marc Zyngier
2020-04-18 15:19 ` Gustavo Pimentel
2020-04-20 9:14 ` Marc Zyngier
2020-04-20 16:08 ` Alan Mikhak
2020-04-20 19:20 ` Alan Mikhak
2020-04-21 8:39 ` Marc Zyngier
2020-04-21 23:44 ` Alan Mikhak
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