Messages in this thread Patch in this message | | | From | Tim Gardner <> | Subject | [PATCH linux-next] ipv4: Fix NULL deference in fnhe_remove_oldest() | Date | Thu, 2 Sep 2021 10:32:05 -0600 |
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Coverity complains that linux-next commit 67d6d681e15b5 ("ipv4: make exception cache less predictible") neglected to check for NULL before dereferencing 'oldest'. It appears to be possible to fall through the for loop without ever setting 'oldest'.
Cc: Eric Dumazet <edumazet@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: David Ahern <dsahern@kernel.org> Cc: Jakub Kicinski <kuba@kernel.org> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Tim Gardner <tim.gardner@canonical.com> --- net/ipv4/route.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index d6899ab5fb39..e85026591a09 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -603,9 +603,11 @@ static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) oldest_p = fnhe_p; } } - fnhe_flush_routes(oldest); - *oldest_p = oldest->fnhe_next; - kfree_rcu(oldest, rcu); + if (oldest) { + fnhe_flush_routes(oldest); + *oldest_p = oldest->fnhe_next; + kfree_rcu(oldest, rcu); + } } static u32 fnhe_hashfun(__be32 daddr) -- 2.33.0
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