From: Pablo Neira Ayuso <pablo@netfilter.org> To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org Subject: [PATCH 8/9] netfilter: nf_tables: fix flowtable list del corruption Date: Thu, 16 Jan 2020 20:50:43 +0100 Message-ID: <20200116195044.326614-9-pablo@netfilter.org> (raw) In-Reply-To: <20200116195044.326614-1-pablo@netfilter.org> From: Florian Westphal <fw@strlen.de> syzbot reported following crash: list_del corruption, ffff88808c9bb000->prev is LIST_POISON2 (dead000000000122) [..] Call Trace: __list_del_entry include/linux/list.h:131 [inline] list_del_rcu include/linux/rculist.h:148 [inline] nf_tables_commit+0x1068/0x3b30 net/netfilter/nf_tables_api.c:7183 [..] The commit transaction list has: NFT_MSG_NEWTABLE NFT_MSG_NEWFLOWTABLE NFT_MSG_DELFLOWTABLE NFT_MSG_DELTABLE A missing generation check during DELTABLE processing causes it to queue the DELFLOWTABLE operation a second time, so we corrupt the list here: case NFT_MSG_DELFLOWTABLE: list_del_rcu(&nft_trans_flowtable(trans)->list); nf_tables_flowtable_notify(&trans->ctx, because we have two different DELFLOWTABLE transactions for the same flowtable. We then call list_del_rcu() twice for the same flowtable->list. The object handling seems to suffer from the same bug so add a generation check too and only queue delete transactions for flowtables/objects that are still active in the next generation. Reported-by: syzbot+37a6804945a3a13b1572@syzkaller.appspotmail.com Fixes: 3b49e2e94e6eb ("netfilter: nf_tables: add flow table netlink frontend") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- net/netfilter/nf_tables_api.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 896a6e8aff91..65f51a2e9c2a 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1048,12 +1048,18 @@ static int nft_flush_table(struct nft_ctx *ctx) } list_for_each_entry_safe(flowtable, nft, &ctx->table->flowtables, list) { + if (!nft_is_active_next(ctx->net, flowtable)) + continue; + err = nft_delflowtable(ctx, flowtable); if (err < 0) goto out; } list_for_each_entry_safe(obj, ne, &ctx->table->objects, list) { + if (!nft_is_active_next(ctx->net, obj)) + continue; + err = nft_delobj(ctx, obj); if (err < 0) goto out; -- 2.11.0
next prev parent reply index Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-16 19:50 [PATCH 0/9] Netfilter updates for net Pablo Neira Ayuso 2020-01-16 19:50 ` [PATCH 1/9] netfilter: fix a use-after-free in mtype_destroy() Pablo Neira Ayuso 2020-01-16 19:50 ` [PATCH 2/9] netfilter: arp_tables: init netns pointer in xt_tgdtor_param struct Pablo Neira Ayuso 2020-01-16 19:50 ` [PATCH 3/9] netfilter: nf_tables: store transaction list locally while requesting module Pablo Neira Ayuso 2020-01-16 19:50 ` [PATCH 4/9] netfilter: nft_tunnel: fix null-attribute check Pablo Neira Ayuso 2020-01-16 19:50 ` [PATCH 5/9] netfilter: nft_tunnel: ERSPAN_VERSION must not be null Pablo Neira Ayuso 2020-01-16 19:50 ` [PATCH 6/9] netfilter: nf_tables: remove WARN and add NLA_STRING upper limits Pablo Neira Ayuso 2020-01-16 19:50 ` [PATCH 7/9] netfilter: nf_tables: fix memory leak in nf_tables_parse_netdev_hooks() Pablo Neira Ayuso 2020-01-16 19:50 ` Pablo Neira Ayuso [this message] 2020-01-16 19:50 ` [PATCH 9/9] netfilter: nat: fix ICMP header corruption on ICMP errors Pablo Neira Ayuso 2020-01-17 9:37 ` [PATCH 0/9] Netfilter updates for net David Miller
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20200116195044.326614-9-pablo@netfilter.org \ --to=pablo@netfilter.org \ --cc=davem@davemloft.net \ --cc=netdev@vger.kernel.org \ --cc=netfilter-devel@vger.kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
Netdev Archive on lore.kernel.org Archives are clonable: git clone --mirror https://lore.kernel.org/netdev/0 netdev/git/0.git git clone --mirror https://lore.kernel.org/netdev/1 netdev/git/1.git # If you have public-inbox 1.1+ installed, you may # initialize and index your mirror using the following commands: public-inbox-init -V2 netdev netdev/ https://lore.kernel.org/netdev \ netdev@vger.kernel.org public-inbox-index netdev Example config snippet for mirrors Newsgroup available over NNTP: nntp://nntp.lore.kernel.org/org.kernel.vger.netdev AGPL code for this site: git clone https://public-inbox.org/public-inbox.git