| Message ID | 20210825231729.401676-2-eric.dumazet@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 4785305c05b25a242e5314cc821f54ade4c18810 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | inet: use siphash in exception handling | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for net |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | warning | 2 maintainers not CCed: dsahern@kernel.org yoshfuji@linux-ipv6.org |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 1 this patch: 1 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 37 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 1 this patch: 1 |
| netdev/header_inline | success | Link |
On Wed, Aug 25, 2021 at 4:17 PM Eric Dumazet <eric.dumazet@gmail.com> wrote: > > From: Eric Dumazet <edumazet@google.com> > > A group of security researchers brought to our attention > the weakness of hash function used in rt6_exception_hash() > > Lets use siphash instead of Jenkins Hash, to considerably > reduce security risks. > > Following patch deals with IPv4. > > Fixes: 35732d01fe31 ("ipv6: introduce a hash table to store dst cache") > Signed-off-by: Eric Dumazet <edumazet@google.com> > Reported-by: Keyu Man <kman001@ucr.edu> > Cc: Wei Wang <weiwan@google.com> > Cc: Martin KaFai Lau <kafai@fb.com> Acked-by: Wei Wang <weiwan@google.com> Thanks Eric! > --- > > > > net/ipv6/route.c | 20 ++++++++++++++------ > 1 file changed, 14 insertions(+), 6 deletions(-) > > diff --git a/net/ipv6/route.c b/net/ipv6/route.c > index b6ddf23d38330ded88509b8507998ce82a72799b..c5e8ecb96426bda619fe242351e40dcf6ff68bcf 100644 > --- a/net/ipv6/route.c > +++ b/net/ipv6/route.c > @@ -41,6 +41,7 @@ > #include <linux/nsproxy.h> > #include <linux/slab.h> > #include <linux/jhash.h> > +#include <linux/siphash.h> > #include <net/net_namespace.h> > #include <net/snmp.h> > #include <net/ipv6.h> > @@ -1484,17 +1485,24 @@ static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket) > static u32 rt6_exception_hash(const struct in6_addr *dst, > const struct in6_addr *src) > { > - static u32 seed __read_mostly; > - u32 val; > + static siphash_key_t rt6_exception_key __read_mostly; > + struct { > + struct in6_addr dst; > + struct in6_addr src; > + } __aligned(SIPHASH_ALIGNMENT) combined = { > + .dst = *dst, > + }; > + u64 val; > > - net_get_random_once(&seed, sizeof(seed)); > - val = jhash2((const u32 *)dst, sizeof(*dst)/sizeof(u32), seed); > + net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key)); > > #ifdef CONFIG_IPV6_SUBTREES > if (src) > - val = jhash2((const u32 *)src, sizeof(*src)/sizeof(u32), val); > + combined.src = *src; > #endif > - return hash_32(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT); > + val = siphash(&combined, sizeof(combined), &rt6_exception_key); > + > + return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT); > } > > /* Helper function to find the cached rt in the hash table > -- > 2.33.0.rc2.250.ged5fa647cd-goog >
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index b6ddf23d38330ded88509b8507998ce82a72799b..c5e8ecb96426bda619fe242351e40dcf6ff68bcf 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -41,6 +41,7 @@ #include <linux/nsproxy.h> #include <linux/slab.h> #include <linux/jhash.h> +#include <linux/siphash.h> #include <net/net_namespace.h> #include <net/snmp.h> #include <net/ipv6.h> @@ -1484,17 +1485,24 @@ static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket) static u32 rt6_exception_hash(const struct in6_addr *dst, const struct in6_addr *src) { - static u32 seed __read_mostly; - u32 val; + static siphash_key_t rt6_exception_key __read_mostly; + struct { + struct in6_addr dst; + struct in6_addr src; + } __aligned(SIPHASH_ALIGNMENT) combined = { + .dst = *dst, + }; + u64 val; - net_get_random_once(&seed, sizeof(seed)); - val = jhash2((const u32 *)dst, sizeof(*dst)/sizeof(u32), seed); + net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key)); #ifdef CONFIG_IPV6_SUBTREES if (src) - val = jhash2((const u32 *)src, sizeof(*src)/sizeof(u32), val); + combined.src = *src; #endif - return hash_32(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT); + val = siphash(&combined, sizeof(combined), &rt6_exception_key); + + return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT); } /* Helper function to find the cached rt in the hash table