diff options
| author | Visa Hankala | 2020-12-30 16:15:53 +0000 |
|---|---|---|
| committer | Steffen Klassert | 2021-01-04 10:35:09 +0100 |
| commit | da64ae2d35d3673233f0403b035d4c6acbf71965 (patch) | |
| tree | 075b05b9a9c7fb640fc74c82d134539a342fef08 /net/xfrm | |
| parent | f6e9ceb7a7fc321a31a9dde93a99b7b4b016a3b3 (diff) | |
xfrm: Fix wraparound in xfrm_policy_addr_delta()
Use three-way comparison for address components to avoid integer
wraparound in the result of xfrm_policy_addr_delta(). This ensures
that the search trees are built and traversed correctly.
Treat IPv4 and IPv6 similarly by returning 0 when prefixlen == 0.
Prefix /0 has only one equivalence class.
Fixes: 9cf545ebd591d ("xfrm: policy: store inexact policies in a tree ordered by destination address")
Signed-off-by: Visa Hankala <visa@hankala.org>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net/xfrm')
| -rw-r--r-- | net/xfrm/xfrm_policy.c | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 2f84136af48a..b74f28cabe24 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -793,15 +793,22 @@ static int xfrm_policy_addr_delta(const xfrm_address_t *a, const xfrm_address_t *b, u8 prefixlen, u16 family) { + u32 ma, mb, mask; unsigned int pdw, pbi; int delta = 0; switch (family) { case AF_INET: - if (sizeof(long) == 4 && prefixlen == 0) - return ntohl(a->a4) - ntohl(b->a4); - return (ntohl(a->a4) & ((~0UL << (32 - prefixlen)))) - - (ntohl(b->a4) & ((~0UL << (32 - prefixlen)))); + if (prefixlen == 0) + return 0; + mask = ~0U << (32 - prefixlen); + ma = ntohl(a->a4) & mask; + mb = ntohl(b->a4) & mask; + if (ma < mb) + delta = -1; + else if (ma > mb) + delta = 1; + break; case AF_INET6: pdw = prefixlen >> 5; pbi = prefixlen & 0x1f; @@ -812,10 +819,13 @@ static int xfrm_policy_addr_delta(const xfrm_address_t *a, return delta; } if (pbi) { - u32 mask = ~0u << (32 - pbi); - - delta = (ntohl(a->a6[pdw]) & mask) - - (ntohl(b->a6[pdw]) & mask); + mask = ~0U << (32 - pbi); + ma = ntohl(a->a6[pdw]) & mask; + mb = ntohl(b->a6[pdw]) & mask; + if (ma < mb) + delta = -1; + else if (ma > mb) + delta = 1; } break; default: |