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authorSteven Toth <stoth@kernellabs.com>2017-06-06 09:30:27 -0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-08-11 08:49:31 -0700
commit12d17d78e3f74b5022f61eee7d6de082e472a401 (patch)
treeb696a7b83ba1a6a49fead8ae86a9caa485897401 /drivers
parent3a63729427acd0ee9f6265d20cf3b9890e8d7a96 (diff)
saa7164: fix double fetch PCIe access condition
commit 6fb05e0dd32e566facb96ea61a48c7488daa5ac3 upstream. Avoid a double fetch by reusing the values from the prior transfer. Originally reported via https://bugzilla.kernel.org/show_bug.cgi?id=195559 Thanks to Pengfei Wang <wpengfeinudt@gmail.com> for reporting. Signed-off-by: Steven Toth <stoth@kernellabs.com> Reported-by: Pengfei Wang <wpengfeinudt@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Cc: Eduardo Valentin <eduval@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/media/pci/saa7164/saa7164-bus.c13
1 files changed, 1 insertions, 12 deletions
diff --git a/drivers/media/pci/saa7164/saa7164-bus.c b/drivers/media/pci/saa7164/saa7164-bus.c
index a18fe5d47238..b4857cd7069e 100644
--- a/drivers/media/pci/saa7164/saa7164-bus.c
+++ b/drivers/media/pci/saa7164/saa7164-bus.c
@@ -393,11 +393,11 @@ int saa7164_bus_get(struct saa7164_dev *dev, struct tmComResInfo* msg,
msg_tmp.size = le16_to_cpu((__force __le16)msg_tmp.size);
msg_tmp.command = le32_to_cpu((__force __le32)msg_tmp.command);
msg_tmp.controlselector = le16_to_cpu((__force __le16)msg_tmp.controlselector);
+ memcpy(msg, &msg_tmp, sizeof(*msg));
/* No need to update the read positions, because this was a peek */
/* If the caller specifically want to peek, return */
if (peekonly) {
- memcpy(msg, &msg_tmp, sizeof(*msg));
goto peekout;
}
@@ -442,21 +442,15 @@ int saa7164_bus_get(struct saa7164_dev *dev, struct tmComResInfo* msg,
space_rem = bus->m_dwSizeGetRing - curr_grp;
if (space_rem < sizeof(*msg)) {
- /* msg wraps around the ring */
- memcpy_fromio(msg, bus->m_pdwGetRing + curr_grp, space_rem);
- memcpy_fromio((u8 *)msg + space_rem, bus->m_pdwGetRing,
- sizeof(*msg) - space_rem);
if (buf)
memcpy_fromio(buf, bus->m_pdwGetRing + sizeof(*msg) -
space_rem, buf_size);
} else if (space_rem == sizeof(*msg)) {
- memcpy_fromio(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
if (buf)
memcpy_fromio(buf, bus->m_pdwGetRing, buf_size);
} else {
/* Additional data wraps around the ring */
- memcpy_fromio(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
if (buf) {
memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp +
sizeof(*msg), space_rem - sizeof(*msg));
@@ -469,15 +463,10 @@ int saa7164_bus_get(struct saa7164_dev *dev, struct tmComResInfo* msg,
} else {
/* No wrapping */
- memcpy_fromio(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
if (buf)
memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg),
buf_size);
}
- /* Convert from little endian to CPU */
- msg->size = le16_to_cpu((__force __le16)msg->size);
- msg->command = le32_to_cpu((__force __le32)msg->command);
- msg->controlselector = le16_to_cpu((__force __le16)msg->controlselector);
/* Update the read positions, adjusting the ring */
saa7164_writel(bus->m_dwGetReadPos, new_grp);