From a2f18db0c68fec96631c10cad9384c196e9008ac Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 4 Jan 2015 15:14:22 +0100 Subject: netfilter: nf_tables: fix flush ruleset chain dependencies Jumping between chains doesn't mix well with flush ruleset. Rules from a different chain and set elements may still refer to us. [ 353.373791] ------------[ cut here ]------------ [ 353.373845] kernel BUG at net/netfilter/nf_tables_api.c:1159! [ 353.373896] invalid opcode: 0000 [#1] SMP [ 353.373942] Modules linked in: intel_powerclamp uas iwldvm iwlwifi [ 353.374017] CPU: 0 PID: 6445 Comm: 31c3.nft Not tainted 3.18.0 #98 [ 353.374069] Hardware name: LENOVO 5129CTO/5129CTO, BIOS 6QET47WW (1.17 ) 07/14/2010 [...] [ 353.375018] Call Trace: [ 353.375046] [] ? nf_tables_commit+0x381/0x540 [ 353.375101] [] nfnetlink_rcv+0x3d8/0x4b0 [ 353.375150] [] netlink_unicast+0x105/0x1a0 [ 353.375200] [] netlink_sendmsg+0x32e/0x790 [ 353.375253] [] sock_sendmsg+0x8e/0xc0 [ 353.375300] [] ? move_addr_to_kernel.part.20+0x19/0x70 [ 353.375357] [] ? move_addr_to_kernel+0x19/0x30 [ 353.375410] [] ? verify_iovec+0x42/0xd0 [ 353.375459] [] ___sys_sendmsg+0x3f0/0x400 [ 353.375510] [] ? native_sched_clock+0x2a/0x90 [ 353.375563] [] ? acct_account_cputime+0x17/0x20 [ 353.375616] [] ? account_user_time+0x88/0xa0 [ 353.375667] [] __sys_sendmsg+0x3d/0x80 [ 353.375719] [] ? int_check_syscall_exit_work+0x34/0x3d [ 353.375776] [] SyS_sendmsg+0xd/0x20 [ 353.375823] [] system_call_fastpath+0x16/0x1b Release objects in this order: rules -> sets -> chains -> tables, to make sure no references to chains are held anymore. Reported-by: Asbjoern Sloth Toennesen Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) (limited to 'net') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 129a8daa4abf..3b3ddb4fb9ee 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -713,16 +713,12 @@ static int nft_flush_table(struct nft_ctx *ctx) struct nft_chain *chain, *nc; struct nft_set *set, *ns; - list_for_each_entry_safe(chain, nc, &ctx->table->chains, list) { + list_for_each_entry(chain, &ctx->table->chains, list) { ctx->chain = chain; err = nft_delrule_by_chain(ctx); if (err < 0) goto out; - - err = nft_delchain(ctx); - if (err < 0) - goto out; } list_for_each_entry_safe(set, ns, &ctx->table->sets, list) { @@ -735,6 +731,14 @@ static int nft_flush_table(struct nft_ctx *ctx) goto out; } + list_for_each_entry_safe(chain, nc, &ctx->table->chains, list) { + ctx->chain = chain; + + err = nft_delchain(ctx); + if (err < 0) + goto out; + } + err = nft_deltable(ctx); out: return err; -- cgit v1.2.3