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authorPablo Neira Ayuso <pablo@netfilter.org>2021-05-05 22:30:49 +0200
committerPablo Neira Ayuso <pablo@netfilter.org>2021-05-05 23:45:48 +0200
commit198ad973839ca4686f3575155ba9ff178289905f (patch)
tree84be795e49b224992fb1ccee0b4d679b364fb919 /net
parentnetfilter: nfnetlink_osf: Fix a missing skb_header_pointer() NULL check (diff)
downloadlinux-198ad973839ca4686f3575155ba9ff178289905f.tar.xz
linux-198ad973839ca4686f3575155ba9ff178289905f.zip
netfilter: remove BUG_ON() after skb_header_pointer()
Several conntrack helpers and the TCP tracker assume that skb_header_pointer() never fails based on upfront header validation. Even if this should not ever happen, BUG_ON() is a too drastic measure, remove them. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/nf_conntrack_ftp.c5
-rw-r--r--net/netfilter/nf_conntrack_h323_main.c3
-rw-r--r--net/netfilter/nf_conntrack_irc.c5
-rw-r--r--net/netfilter/nf_conntrack_pptp.c4
-rw-r--r--net/netfilter/nf_conntrack_proto_tcp.c6
-rw-r--r--net/netfilter/nf_conntrack_sane.c5
6 files changed, 21 insertions, 7 deletions
diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index b22801f97bce..a414274338cf 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -413,7 +413,10 @@ static int help(struct sk_buff *skb,
spin_lock_bh(&nf_ftp_lock);
fb_ptr = skb_header_pointer(skb, dataoff, datalen, ftp_buffer);
- BUG_ON(fb_ptr == NULL);
+ if (!fb_ptr) {
+ spin_unlock_bh(&nf_ftp_lock);
+ return NF_ACCEPT;
+ }
ends_in_nl = (fb_ptr[datalen - 1] == '\n');
seq = ntohl(th->seq) + datalen;
diff --git a/net/netfilter/nf_conntrack_h323_main.c b/net/netfilter/nf_conntrack_h323_main.c
index 8ba037b76ad3..aafaff00baf1 100644
--- a/net/netfilter/nf_conntrack_h323_main.c
+++ b/net/netfilter/nf_conntrack_h323_main.c
@@ -146,7 +146,8 @@ static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
/* Get first TPKT pointer */
tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
h323_buffer);
- BUG_ON(tpkt == NULL);
+ if (!tpkt)
+ goto clear_out;
/* Validate TPKT identifier */
if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
diff --git a/net/netfilter/nf_conntrack_irc.c b/net/netfilter/nf_conntrack_irc.c
index e40988a2f22f..08ee4e760a3d 100644
--- a/net/netfilter/nf_conntrack_irc.c
+++ b/net/netfilter/nf_conntrack_irc.c
@@ -143,7 +143,10 @@ static int help(struct sk_buff *skb, unsigned int protoff,
spin_lock_bh(&irc_buffer_lock);
ib_ptr = skb_header_pointer(skb, dataoff, skb->len - dataoff,
irc_buffer);
- BUG_ON(ib_ptr == NULL);
+ if (!ib_ptr) {
+ spin_unlock_bh(&irc_buffer_lock);
+ return NF_ACCEPT;
+ }
data = ib_ptr;
data_limit = ib_ptr + skb->len - dataoff;
diff --git a/net/netfilter/nf_conntrack_pptp.c b/net/netfilter/nf_conntrack_pptp.c
index 5105d4250012..7d5708b92138 100644
--- a/net/netfilter/nf_conntrack_pptp.c
+++ b/net/netfilter/nf_conntrack_pptp.c
@@ -544,7 +544,9 @@ conntrack_pptp_help(struct sk_buff *skb, unsigned int protoff,
nexthdr_off = protoff;
tcph = skb_header_pointer(skb, nexthdr_off, sizeof(_tcph), &_tcph);
- BUG_ON(!tcph);
+ if (!tcph)
+ return NF_ACCEPT;
+
nexthdr_off += tcph->doff * 4;
datalen = tcplen - tcph->doff * 4;
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index 318b8f723349..34e22416a721 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -338,7 +338,8 @@ static void tcp_options(const struct sk_buff *skb,
ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr),
length, buff);
- BUG_ON(ptr == NULL);
+ if (!ptr)
+ return;
state->td_scale =
state->flags = 0;
@@ -394,7 +395,8 @@ static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr),
length, buff);
- BUG_ON(ptr == NULL);
+ if (!ptr)
+ return;
/* Fast path for timestamp-only option */
if (length == TCPOLEN_TSTAMP_ALIGNED
diff --git a/net/netfilter/nf_conntrack_sane.c b/net/netfilter/nf_conntrack_sane.c
index 1aebd6569d4e..fcb33b1d5456 100644
--- a/net/netfilter/nf_conntrack_sane.c
+++ b/net/netfilter/nf_conntrack_sane.c
@@ -95,7 +95,10 @@ static int help(struct sk_buff *skb,
spin_lock_bh(&nf_sane_lock);
sb_ptr = skb_header_pointer(skb, dataoff, datalen, sane_buffer);
- BUG_ON(sb_ptr == NULL);
+ if (!sb_ptr) {
+ spin_unlock_bh(&nf_sane_lock);
+ return NF_ACCEPT;
+ }
if (dir == IP_CT_DIR_ORIGINAL) {
if (datalen != sizeof(struct sane_request))