From: Miao-chen Chou <mcchou@xxxxxxxxxxxx>
This patch introduces a temp variable to prevent the access to an unaligned
struct member. Since the struct rfcomm_rpn is used from PDU, enforcing alignment
is not a solution due to padding.
---
monitor/rfcomm.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/monitor/rfcomm.c b/monitor/rfcomm.c
index b32ad40..7f1f23e 100644
--- a/monitor/rfcomm.c
+++ b/monitor/rfcomm.c
@@ -199,6 +199,7 @@ static inline bool mcc_rpn(struct rfcomm_frame *rfcomm_frame, uint8_t indent)
{
struct l2cap_frame *frame = &rfcomm_frame->l2cap_frame;
struct rfcomm_rpn rpn;
+ uint16_t pm;
if (!l2cap_frame_get_u8(frame, &rpn.dlci))
return false;
@@ -235,8 +236,11 @@ static inline bool mcc_rpn(struct rfcomm_frame *rfcomm_frame, uint8_t indent)
GET_RPN_RTCI(rpn.io), GET_RPN_RTCO(rpn.io), rpn.xon,
rpn.xoff);
- if (!l2cap_frame_get_le16(frame, &rpn.pm))
+ /* prevent unaligned memory access */
+ pm = rpn.pm;
+ if (!l2cap_frame_get_le16(frame, &pm))
return false;
+ rpn.pm = pm;
print_field("%*cpm 0x%04x", indent, ' ', rpn.pm);
@@ -265,6 +269,7 @@ static inline bool mcc_pn(struct rfcomm_frame *rfcomm_frame, uint8_t indent)
{
struct l2cap_frame *frame = &rfcomm_frame->l2cap_frame;
struct rfcomm_pn pn;
+ uint16_t mtu;
/* rfcomm_pn struct is defined in rfcomm.h */
@@ -284,8 +289,11 @@ static inline bool mcc_pn(struct rfcomm_frame *rfcomm_frame, uint8_t indent)
if (!l2cap_frame_get_u8(frame, &pn.ack_timer))
return false;
- if (!l2cap_frame_get_le16(frame, &pn.mtu))
+ /* prevent unaligned memory access */
+ mtu = pn.mtu;
+ if (!l2cap_frame_get_le16(frame, &mtu))
return false;
+ pn.mtu = mtu;
if (!l2cap_frame_get_u8(frame, &pn.max_retrans))
return false;
--
2.8.0.rc3.226.g39d4020
--
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