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![]() As reported by Alan Cox, and verified by Lin Ming, when a user attempts to add a CIPSO option to a socket using the CIPSO_V4_TAG_LOCAL tag the kernel dies a terrible death when it attempts to follow a NULL pointer (the skb argument to cipso_v4_validate() is NULL when called via the setsockopt() syscall). This patch fixes this by first checking to ensure that the skb is non-NULL before using it to find the incoming network interface. In the unlikely case where the skb is NULL and the user attempts to add a CIPSO option with the _TAG_LOCAL tag we return an error as this is not something we want to allow. A simple reproducer, kindly supplied by Lin Ming, although you must have the CIPSO DOI #3 configure on the system first or you will be caught early in cipso_v4_validate(): #include <sys/types.h> #include <sys/socket.h> #include <linux/ip.h> #include <linux/in.h> #include <string.h> struct local_tag { char type; char length; char info[4]; }; struct cipso { char type; char length; char doi[4]; struct local_tag local; }; int main(int argc, char **argv) { int sockfd; struct cipso cipso = { .type = IPOPT_CIPSO, .length = sizeof(struct cipso), .local = { .type = 128, .length = sizeof(struct local_tag), }, }; memset(cipso.doi, 0, 4); cipso.doi[3] = 3; sockfd = socket(AF_INET, SOCK_DGRAM, 0); #define SOL_IP 0 setsockopt(sockfd, SOL_IP, IP_OPTIONS, &cipso, sizeof(struct cipso)); return 0; } CC: Lin Ming <mlin@ss.pku.edu.cn> Reported-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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9p | ||
802 | ||
8021q | ||
appletalk | ||
atm | ||
ax25 | ||
batman-adv | ||
bluetooth | ||
bridge | ||
caif | ||
can | ||
ceph | ||
core | ||
dcb | ||
dccp | ||
decnet | ||
dns_resolver | ||
dsa | ||
ethernet | ||
ieee802154 | ||
ipv4 | ||
ipv6 | ||
ipx | ||
irda | ||
iucv | ||
key | ||
l2tp | ||
lapb | ||
llc | ||
mac80211 | ||
mac802154 | ||
netfilter | ||
netlabel | ||
netlink | ||
netrom | ||
nfc | ||
openvswitch | ||
packet | ||
phonet | ||
rds | ||
rfkill | ||
rose | ||
rxrpc | ||
sched | ||
sctp | ||
sunrpc | ||
tipc | ||
unix | ||
wanrouter | ||
wimax | ||
wireless | ||
x25 | ||
xfrm | ||
compat.c | ||
Kconfig | ||
Makefile | ||
nonet.c | ||
socket.c | ||
sysctl_net.c |