From ed7809d9c41b514115ddffaa860694393c2016b3 Mon Sep 17 00:00:00 2001
From: Jesper Juhl <jj@chaosbits.net>
Date: Thu, 13 Jan 2011 21:53:38 +0100
Subject: batman-adv: Even Batman should not dereference NULL pointers

There's a problem in net/batman-adv/unicast.c::frag_send_skb().
dev_alloc_skb() allocates memory and may fail, thus returning NULL. If
this happens we'll pass a NULL pointer on to skb_split() which in turn
hands it to skb_split_inside_header() from where it gets passed to
skb_put() that lets skb_tail_pointer() play with it and that function
dereferences it. And thus the bat dies.

While I was at it I also moved the call to dev_alloc_skb() above the
assignment to 'unicast_packet' since there's no reason to do that
assignment if the memory allocation fails.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>

diff --git a/net/batman-adv/unicast.c b/net/batman-adv/unicast.c
index dc2e28b..ee41fef 100644
--- a/net/batman-adv/unicast.c
+++ b/net/batman-adv/unicast.c
@@ -229,10 +229,12 @@ int frag_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv,
 	if (!bat_priv->primary_if)
 		goto dropped;
 
-	unicast_packet = (struct unicast_packet *) skb->data;
+	frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len);
+	if (!frag_skb)
+		goto dropped;
 
+	unicast_packet = (struct unicast_packet *) skb->data;
 	memcpy(&tmp_uc, unicast_packet, uc_hdr_len);
-	frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len);
 	skb_split(skb, frag_skb, data_len / 2);
 
 	if (my_skb_head_push(skb, ucf_hdr_len - uc_hdr_len) < 0 ||
-- 
cgit v0.10.2


From aa0adb1a85e159cf57f0e11282bc6c9e3606a5f3 Mon Sep 17 00:00:00 2001
From: Sven Eckelmann <sven@narfation.org>
Date: Sat, 15 Jan 2011 14:39:43 +0000
Subject: batman-adv: Use "__attribute__" shortcut macros

Linux 2.6.21 defines different macros for __attribute__ which are also
used inside batman-adv. The next version of checkpatch.pl warns about
the usage of __attribute__((packed))).

Linux 2.6.33 defines an extra macro __always_unused which is used to
assist source code analyzers and can be used to removed the last
existing __attribute__ inside the source code.

Signed-off-by: Sven Eckelmann <sven@narfation.org>

diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h
index d4d9926..65106fb 100644
--- a/net/batman-adv/main.h
+++ b/net/batman-adv/main.h
@@ -151,9 +151,9 @@ int debug_log(struct bat_priv *bat_priv, char *fmt, ...);
 	}							\
 	while (0)
 #else /* !CONFIG_BATMAN_ADV_DEBUG */
-static inline void bat_dbg(char type __attribute__((unused)),
-			   struct bat_priv *bat_priv __attribute__((unused)),
-			   char *fmt __attribute__((unused)), ...)
+static inline void bat_dbg(char type __always_unused,
+			   struct bat_priv *bat_priv __always_unused,
+			   char *fmt __always_unused, ...)
 {
 }
 #endif
diff --git a/net/batman-adv/packet.h b/net/batman-adv/packet.h
index b49fdf7..2284e81 100644
--- a/net/batman-adv/packet.h
+++ b/net/batman-adv/packet.h
@@ -63,7 +63,7 @@ struct batman_packet {
 	uint8_t  num_hna;
 	uint8_t  gw_flags;  /* flags related to gateway class */
 	uint8_t  align;
-} __attribute__((packed));
+} __packed;
 
 #define BAT_PACKET_LEN sizeof(struct batman_packet)
 
@@ -76,7 +76,7 @@ struct icmp_packet {
 	uint8_t  orig[6];
 	uint16_t seqno;
 	uint8_t  uid;
-} __attribute__((packed));
+} __packed;
 
 #define BAT_RR_LEN 16
 
@@ -93,14 +93,14 @@ struct icmp_packet_rr {
 	uint8_t  uid;
 	uint8_t  rr_cur;
 	uint8_t  rr[BAT_RR_LEN][ETH_ALEN];
-} __attribute__((packed));
+} __packed;
 
 struct unicast_packet {
 	uint8_t  packet_type;
 	uint8_t  version;  /* batman version field */
 	uint8_t  dest[6];
 	uint8_t  ttl;
-} __attribute__((packed));
+} __packed;
 
 struct unicast_frag_packet {
 	uint8_t  packet_type;
@@ -110,7 +110,7 @@ struct unicast_frag_packet {
 	uint8_t  flags;
 	uint8_t  orig[6];
 	uint16_t seqno;
-} __attribute__((packed));
+} __packed;
 
 struct bcast_packet {
 	uint8_t  packet_type;
@@ -118,7 +118,7 @@ struct bcast_packet {
 	uint8_t  orig[6];
 	uint8_t  ttl;
 	uint32_t seqno;
-} __attribute__((packed));
+} __packed;
 
 struct vis_packet {
 	uint8_t  packet_type;
@@ -131,6 +131,6 @@ struct vis_packet {
 				  * neighbors */
 	uint8_t  target_orig[6]; /* who should receive this packet */
 	uint8_t  sender_orig[6]; /* who sent or rebroadcasted this packet */
-} __attribute__((packed));
+} __packed;
 
 #endif /* _NET_BATMAN_ADV_PACKET_H_ */
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 97cb23d..bf3f6f5 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -246,13 +246,13 @@ struct vis_info {
 	/* this packet might be part of the vis send queue. */
 	struct sk_buff *skb_packet;
 	/* vis_info may follow here*/
-} __attribute__((packed));
+} __packed;
 
 struct vis_info_entry {
 	uint8_t  src[ETH_ALEN];
 	uint8_t  dest[ETH_ALEN];
 	uint8_t  quality;	/* quality = 0 means HNA */
-} __attribute__((packed));
+} __packed;
 
 struct recvlist_node {
 	struct list_head list;
-- 
cgit v0.10.2