[DCCP]: Unaligned pointer access

This fixes `unaligned (read) access' errors of the type

Kernel unaligned access at TPC[100f970c] dccp_parse_options+0x4f4/0x7e0 [dccp]
Kernel unaligned access at TPC[1011f2e4] ccid3_hc_tx_parse_options+0x1ac/0x380 [dccp_ccid3]
Kernel unaligned access at TPC[100f9898] dccp_parse_options+0x680/0x880 [dccp]

by using the get_unaligned macro for parsing options.

Commiter note: Preserved the sparse __be{16,32} annotations.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 7 insertions, 4 deletions

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 25772c326172..05f263e9160d 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -40,6 +40,8 @@
 #include "lib/tfrc.h"
 #include "ccid3.h"
 
+#include <asm/unaligned.h>
+
 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
 static int ccid3_debug;
 #define ccid3_pr_debug(format, a...)    DCCP_PR_DEBUG(ccid3_debug, format, ##a)
@@ -544,6 +546,7 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
         const struct dccp_sock *dp = dccp_sk(sk);
         struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
         struct ccid3_options_received *opt_recv;
+        __be32 opt_val;
 
         opt_recv = &hctx->ccid3hctx_options_received;
 
@@ -563,8 +566,8 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
                                   dccp_role(sk), sk, len);
                         rc = -EINVAL;
                 } else {
-                        opt_recv->ccid3or_loss_event_rate =
-                                                ntohl(*(__be32 *)value);
+                        opt_val = get_unaligned((__be32 *)value);
+                        opt_recv->ccid3or_loss_event_rate = ntohl(opt_val);
                         ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n",
                                        dccp_role(sk), sk,
                                        opt_recv->ccid3or_loss_event_rate);
@@ -585,8 +588,8 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
                                   dccp_role(sk), sk, len);
                         rc = -EINVAL;
                 } else {
-                        opt_recv->ccid3or_receive_rate =
-                                                ntohl(*(__be32 *)value);
+                        opt_val = get_unaligned((__be32 *)value);
+                        opt_recv->ccid3or_receive_rate = ntohl(opt_val);
                         ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n",
                                        dccp_role(sk), sk,
                                        opt_recv->ccid3or_receive_rate);