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| author | Daniel Borkmann <dborkman@redhat.com> | 2013-09-07 17:13:20 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-09-12 00:09:59 +0400 |
| commit | ae7b4e1f213aa659aedf9c6ecad0bf5f0476e1e2 (patch) | |
| tree | c4bebb0cdc317a32fec9d1eddaf8fa681380e751 /net/ipv6 | |
| parent | 3bf4b5b11d381fed6a94a7e487e01c8b3bc436b9 (diff) | |
| download | linux-ae7b4e1f213aa659aedf9c6ecad0bf5f0476e1e2.tar.xz | |
net: fib: fib6_add: fix potential NULL pointer dereference
When the kernel is compiled with CONFIG_IPV6_SUBTREES, and we return
with an error in fn = fib6_add_1(), then error codes are encoded into
the return pointer e.g. ERR_PTR(-ENOENT). In such an error case, we
write the error code into err and jump to out, hence enter the if(err)
condition. Now, if CONFIG_IPV6_SUBTREES is enabled, we check for:
if (pn != fn && pn->leaf == rt)
...
if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO))
...
Since pn is NULL and fn is f.e. ERR_PTR(-ENOENT), then pn != fn
evaluates to true and causes a NULL-pointer dereference on further
checks on pn. Fix it, by setting both NULL in error case, so that
pn != fn already evaluates to false and no further dereference
takes place.
This was first correctly implemented in 4a287eba2 ("IPv6 routing,
NLM_F_* flag support: REPLACE and EXCL flags support, warn about
missing CREATE flag"), but the bug got later on introduced by
188c517a0 ("ipv6: return errno pointers consistently for fib6_add_1()").
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Lin Ming <mlin@ss.pku.edu.cn>
Cc: Matti Vaittinen <matti.vaittinen@nsn.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Matti Vaittinen <matti.vaittinen@nsn.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/ip6_fib.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index 73db48eba1c4..5bec666aba61 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -825,9 +825,9 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info) fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst), allow_create, replace_required); - if (IS_ERR(fn)) { err = PTR_ERR(fn); + fn = NULL; goto out; } |