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authorNeal Cardwell <ncardwell@google.com>2012-12-08 19:43:23 +0000
committerDavid S. Miller <davem@davemloft.net>2012-12-09 18:59:37 -0500
commitf67caec9068cee426ec23cf9005a1dee2ecad187 (patch)
treef1096bdda02c0d95e02cfb1ee1b3f53c21a24fa1
parent405c005949e47b6e91359159c24753519ded0c67 (diff)
inet_diag: avoid unsafe and nonsensical prefix matches in inet_diag_bc_run()
Add logic to check the address family of the user-supplied conditional and the address family of the connection entry. We now do not do prefix matching of addresses from different address families (AF_INET vs AF_INET6), except for the previously existing support for having an IPv4 prefix match an IPv4-mapped IPv6 address (which this commit maintains as-is). This change is needed for two reasons: (1) The addresses are different lengths, so comparing a 128-bit IPv6 prefix match condition to a 32-bit IPv4 connection address can cause us to unwittingly walk off the end of the IPv4 address and read garbage or oops. (2) The IPv4 and IPv6 address spaces are semantically distinct, so a simple bit-wise comparison of the prefixes is not meaningful, and would lead to bogus results (except for the IPv4-mapped IPv6 case, which this commit maintains). Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/ipv4/inet_diag.c28
1 files changed, 17 insertions, 11 deletions
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 529747d07a2..95f1a458371 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -432,25 +432,31 @@ static int inet_diag_bc_run(const struct nlattr *_bc,
break;
}
- if (cond->prefix_len == 0)
- break;
-
if (op->code == INET_DIAG_BC_S_COND)
addr = entry->saddr;
else
addr = entry->daddr;
+ if (cond->family != AF_UNSPEC &&
+ cond->family != entry->family) {
+ if (entry->family == AF_INET6 &&
+ cond->family == AF_INET) {
+ if (addr[0] == 0 && addr[1] == 0 &&
+ addr[2] == htonl(0xffff) &&
+ bitstring_match(addr + 3,
+ cond->addr,
+ cond->prefix_len))
+ break;
+ }
+ yes = 0;
+ break;
+ }
+
+ if (cond->prefix_len == 0)
+ break;
if (bitstring_match(addr, cond->addr,
cond->prefix_len))
break;
- if (entry->family == AF_INET6 &&
- cond->family == AF_INET) {
- if (addr[0] == 0 && addr[1] == 0 &&
- addr[2] == htonl(0xffff) &&
- bitstring_match(addr + 3, cond->addr,
- cond->prefix_len))
- break;
- }
yes = 0;
break;
}