Messages in this thread Patch in this message | | | Subject | Re: [PATCH] ipv4: only allow increasing fib_info_hash_size | From | David Ahern <> | Date | Tue, 12 Oct 2021 20:33:19 -0600 |
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On 10/12/21 7:10 PM, 张凯 wrote: > > 1) Below shift operation will set fib_info_hash_size to zero if there > are so many routes: > unsigned int new_size = fib_info_hash_size << 1; > > This will wrap value of fib_info_hash_size, and a lot of fib_info > will insert to a small hash bucket. > so this patch disables above wrap. > 2) Check whether fib_info_hash_size is zero only needed after allocation > failed: > if (!new_info_hash || !new_laddrhash) { > >
why not something simpler like this:
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 3364cb9c67e0..5c4bd1cebe0a 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -1401,6 +1401,10 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
if (!new_size) new_size = 16; + + if (new_size < fib_info_hash_size) + goto failure; + bytes = new_size * sizeof(struct hlist_head *); new_info_hash = fib_info_hash_alloc(bytes); new_laddrhash = fib_info_hash_alloc(bytes);
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