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| author | Wei Wang <weiwan@google.com> | 2017-10-13 15:01:08 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-10-16 21:06:12 +0100 |
| commit | 0e80193bd8c1d97654f1a2f45934e7372e9a512e (patch) | |
| tree | de451403c6ee2bc38dca0eed86a9d0254dc06efe /net/ipv6 | |
| parent | 9db9583839b760fc492a7b288edfe2213184a579 (diff) | |
| download | linux-0e80193bd8c1d97654f1a2f45934e7372e9a512e.tar.bz2 | |
ipv6: check fn before doing FIB6_SUBTREE(fn)
In fib6_locate(), we need to first make sure fn is not NULL before doing
FIB6_SUBTREE(fn) to avoid crash.
This fixes the following static checker warning:
net/ipv6/ip6_fib.c:1462 fib6_locate()
warn: variable dereferenced before check 'fn' (see line 1459)
net/ipv6/ip6_fib.c
1458 if (src_len) {
1459 struct fib6_node *subtree = FIB6_SUBTREE(fn);
^^^^^^^^^^^^^^^^
We shifted this dereference
1460
1461 WARN_ON(saddr == NULL);
1462 if (fn && subtree)
^^
before the check for NULL.
1463 fn = fib6_locate_1(subtree, saddr, src_len,
1464 offsetof(struct rt6_info, rt6i_src)
Fixes: 66f5d6ce53e6 ("ipv6: replace rwlock with rcu and spinlock in fib6_table")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/ip6_fib.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index c2ecd5ec638a..548af48212fc 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -1456,13 +1456,16 @@ struct fib6_node *fib6_locate(struct fib6_node *root, #ifdef CONFIG_IPV6_SUBTREES if (src_len) { - struct fib6_node *subtree = FIB6_SUBTREE(fn); - WARN_ON(saddr == NULL); - if (fn && subtree) - fn = fib6_locate_1(subtree, saddr, src_len, + if (fn) { + struct fib6_node *subtree = FIB6_SUBTREE(fn); + + if (subtree) { + fn = fib6_locate_1(subtree, saddr, src_len, offsetof(struct rt6_info, rt6i_src), exact_match); + } + } } #endif |