From 63045bfd3c8dbe9c8bee7e33291202725154cb2c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 10 Jan 2022 19:33:36 -0800 Subject: netfilter: nf_tables: don't use 'data_size' uninitialized Commit 2c865a8a28a1 ("netfilter: nf_tables: add rule blob layout") never initialized the new 'data_size' variable. I'm not sure how it ever worked, but it might have worked almost by accident - gcc seems to occasionally miss these kinds of 'variable used uninitialized' situations, but I've seen it do so because it ended up zero-initializing them due to some other simplification. But clang is very unhappy about it all, and correctly reports net/netfilter/nf_tables_api.c:8278:4: error: variable 'data_size' is uninitialized when used here [-Werror,-Wuninitialized] data_size += sizeof(*prule) + rule->dlen; ^~~~~~~~~ net/netfilter/nf_tables_api.c:8263:30: note: initialize the variable 'data_size' to silence this warning unsigned int size, data_size; ^ = 0 1 error generated. and this fix just initializes 'data_size' to zero before the loop. Fixes: 2c865a8a28a1 ("netfilter: nf_tables: add rule blob layout") Cc: Pablo Neira Ayuso Cc: Jakub Kicinski Cc: David Miller Signed-off-by: Linus Torvalds --- net/netfilter/nf_tables_api.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index eb12fc9b803d..77938b1042f3 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -8273,6 +8273,7 @@ static int nf_tables_commit_chain_prepare(struct net *net, struct nft_chain *cha rule = list_entry(&chain->rules, struct nft_rule, list); i = 0; + data_size = 0; list_for_each_entry_continue(rule, &chain->rules, list) { if (nft_is_active_next(net, rule)) { data_size += sizeof(*prule) + rule->dlen; -- cgit v1.2.3