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authorAlexander Duyck <aduyck@mirantis.com>2016-01-28 13:42:24 -0800
committerDavid S. Miller <davem@davemloft.net>2016-01-29 19:41:00 -0800
commita5829f536b3d11a57617e83d4bcb2b7d70671e98 (patch)
tree3c4133a1240bf8e40ec6ea4ff964ddc101c4354d /net/ipv4
parent59a557be385b66c1da20e9cfc6ff6c2e676c6804 (diff)
downloadlinux-a5829f536b3d11a57617e83d4bcb2b7d70671e98.tar.bz2
fib_trie: Fix shift by 32 in fib_table_lookup
The fib_table_lookup function had a shift by 32 that triggered a UBSAN warning. This was due to the fact that I had placed the shift first and then followed it with the check for the suffix length to ignore the undefined behavior. If we reorder this so that we verify the suffix is less than 32 before shifting the value we can avoid the issue. Reported-by: Toralf Förster <toralf.foerster@gmx.de> Signed-off-by: Alexander Duyck <aduyck@mirantis.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/fib_trie.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 744e5936c10d..22e73171ea63 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1396,9 +1396,10 @@ found:
struct fib_info *fi = fa->fa_info;
int nhsel, err;
- if ((index >= (1ul << fa->fa_slen)) &&
- ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen != KEYLENGTH)))
- continue;
+ if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) {
+ if (index >= (1ul << fa->fa_slen))
+ continue;
+ }
if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
continue;
if (fi->fib_dead)