kernel/linux.git/include/linux/netfilter, branch v4.19.248

netfilter: x_tables: Use correct memory barriers.

2021-03-30T12:37:02+00:00

[ Upstream commit 175e476b8cdf2a4de7432583b49c871345e4f8a1 ] When a new table value was assigned, it was followed by a write memory barrier. This ensured that all writes before this point would complete before any writes after this point. However, to determine whether the rules are unused, the sequence counter is read. To ensure that all writes have been done before these reads, a full memory barrier is needed, not just a write memory barrier. The same argument applies when incrementing the counter, before the rules are read. Changing to using smp_mb() instead of smp_wmb() fixes the kernel panic reported in cc00bcaa5899 (which is still present), while still maintaining the same speed of replacing tables. The smb_mb() barriers potentially slow the packet path, however testing has shown no measurable change in performance on a 4-core MIPS64 platform. Fixes: 7f5c6d4f665b ("netfilter: get rid of atomic ops in fast path") Signed-off-by: Mark Tomlinson Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

Revert "netfilter: x_tables: Switch synchronization to RCU"

2021-03-30T12:37:02+00:00

[ Upstream commit d3d40f237480abf3268956daf18cdc56edd32834 ] This reverts commit cc00bcaa589914096edef7fb87ca5cee4a166b5c. This (and the preceding) patch basically re-implemented the RCU mechanisms of patch 784544739a25. That patch was replaced because of the performance problems that it created when replacing tables. Now, we have the same issue: the call to synchronize_rcu() makes replacing tables slower by as much as an order of magnitude. Prior to using RCU a script calling "iptables" approx. 200 times was taking 1.16s. With RCU this increased to 11.59s. Revert these patches and fix the issue in a different way. Signed-off-by: Mark Tomlinson Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: x_tables: Switch synchronization to RCU

2020-12-30T10:25:45+00:00

[ Upstream commit cc00bcaa589914096edef7fb87ca5cee4a166b5c ] When running concurrent iptables rules replacement with data, the per CPU sequence count is checked after the assignment of the new information. The sequence count is used to synchronize with the packet path without the use of any explicit locking. If there are any packets in the packet path using the table information, the sequence count is incremented to an odd value and is incremented to an even after the packet process completion. The new table value assignment is followed by a write memory barrier so every CPU should see the latest value. If the packet path has started with the old table information, the sequence counter will be odd and the iptables replacement will wait till the sequence count is even prior to freeing the old table info. However, this assumes that the new table information assignment and the memory barrier is actually executed prior to the counter check in the replacement thread. If CPU decides to execute the assignment later as there is no user of the table information prior to the sequence check, the packet path in another CPU may use the old table information. The replacement thread would then free the table information under it leading to a use after free in the packet processing context- Unable to handle kernel NULL pointer dereference at virtual address 000000000000008e pc : ip6t_do_table+0x5d0/0x89c lr : ip6t_do_table+0x5b8/0x89c ip6t_do_table+0x5d0/0x89c ip6table_filter_hook+0x24/0x30 nf_hook_slow+0x84/0x120 ip6_input+0x74/0xe0 ip6_rcv_finish+0x7c/0x128 ipv6_rcv+0xac/0xe4 __netif_receive_skb+0x84/0x17c process_backlog+0x15c/0x1b8 napi_poll+0x88/0x284 net_rx_action+0xbc/0x23c __do_softirq+0x20c/0x48c This could be fixed by forcing instruction order after the new table information assignment or by switching to RCU for the synchronization. Fixes: 80055dab5de0 ("netfilter: x_tables: make xt_replace_table wait until old rules are not used anymore") Reported-by: Sean Tranchetti Reported-by: kernel test robot Suggested-by: Florian Westphal Signed-off-by: Subash Abhinov Kasiviswanathan Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: conntrack: allow sctp hearbeat after connection re-use

2020-09-17T11:45:24+00:00

[ Upstream commit cc5453a5b7e90c39f713091a7ebc53c1f87d1700 ] If an sctp connection gets re-used, heartbeats are flagged as invalid because their vtag doesn't match. Handle this in a similar way as TCP conntrack when it suspects that the endpoints and conntrack are out-of-sync. When a HEARTBEAT request fails its vtag validation, flag this in the conntrack state and accept the packet. When a HEARTBEAT_ACK is received with an invalid vtag in the reverse direction after we allowed such a HEARTBEAT through, assume we are out-of-sync and re-set the vtag info. v2: remove left-over snippet from an older incarnation that moved new_state/old_state assignments, thats not needed so keep that as-is. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: nfnetlink: nfnetlink_unicast() reports EAGAIN instead of ENOBUFS

2020-09-09T17:04:26+00:00

[ Upstream commit ee921183557af39c1a0475f982d43b0fcac25e2e ] Frontend callback reports EAGAIN to nfnetlink to retry a command, this is used to signal that module autoloading is required. Unfortunately, nlmsg_unicast() reports EAGAIN in case the receiver socket buffer gets full, so it enters a busy-loop. This patch updates nfnetlink_unicast() to turn EAGAIN into ENOBUFS and to use nlmsg_unicast(). Remove the flags field in nfnetlink_unicast() since this is always MSG_DONTWAIT in the existing code which is exactly what nlmsg_unicast() passes to netlink_unicast() as parameter. Fixes: 96518518cc41 ("netfilter: add nftables") Reported-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: nf_conntrack_pptp: fix compilation warning with W=1 build

2020-06-03T06:19:49+00:00

commit 4946ea5c1237036155c3b3a24f049fd5f849f8f6 upstream. >> include/linux/netfilter/nf_conntrack_pptp.h:13:20: warning: 'const' type qualifier on return type has no effect [-Wignored-qualifiers] extern const char *const pptp_msg_name(u_int16_t msg); ^~~~~~ Reported-by: kbuild test robot Fixes: 4c559f15efcc ("netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code

2020-06-03T06:19:47+00:00

commit 4c559f15efcc43b996f4da528cd7f9483aaca36d upstream. Dan Carpenter says: "Smatch complains that the value for "cmd" comes from the network and can't be trusted." Add pptp_msg_name() helper function that checks for the array boundary. Fixes: f09943fefe6b ("[NETFILTER]: nf_conntrack/nf_nat: add PPTP helper port") Reported-by: Dan Carpenter Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: ipset: use bitmap infrastructure completely

2020-01-29T15:43:24+00:00

commit 32c72165dbd0e246e69d16a3ad348a4851afd415 upstream. The bitmap allocation did not use full unsigned long sizes when calculating the required size and that was triggered by KASAN as slab-out-of-bounds read in several places. The patch fixes all of them. Reported-by: syzbot+fabca5cbf5e54f3fe2de@syzkaller.appspotmail.com Reported-by: syzbot+827ced406c9a1d9570ed@syzkaller.appspotmail.com Reported-by: syzbot+190d63957b22ef673ea5@syzkaller.appspotmail.com Reported-by: syzbot+dfccdb2bdb4a12ad425e@syzkaller.appspotmail.com Reported-by: syzbot+df0d0f5895ef1f41a65b@syzkaller.appspotmail.com Reported-by: syzbot+b08bd19bb37513357fd4@syzkaller.appspotmail.com Reported-by: syzbot+53cdd0ec0bbabd53370a@syzkaller.appspotmail.com Signed-off-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: nfnetlink_cttimeout: fetch timeouts for udplite and gre, too

2019-04-17T06:38:46+00:00

commit 89259088c1b7fecb43e8e245dc931909132a4e03 upstream syzbot was able to trigger the WARN in cttimeout_default_get() by passing UDPLITE as l4protocol. Alias UDPLITE to UDP, both use same timeout values. Furthermore, also fetch GRE timeouts. GRE is a bit more complicated, as it still can be a module and its netns_proto_gre struct layout isn't visible outside of the gre module. Can't move timeouts around, it appears conntrack sysctl unregister assumes net_generic() returns nf_proto_net, so we get crash. Expose layout of netns_proto_gre instead. A followup nf-next patch could make gre tracker be built-in as well if needed, its not that large. Last, make the WARN() mention the missing protocol value in case anything else is missing. Reported-by: syzbot+2fae8fa157dd92618cae@syzkaller.appspotmail.com Fixes: 8866df9264a3 ("netfilter: nfnetlink_cttimeout: pass default timeout policy to obj_to_nlattr") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Zubin Mithra Signed-off-by: Sasha Levin (Microsoft)

netfilter: nf_tables: fix suspicious RCU usage in nft_chain_stats_replace()

2019-01-13T08:50:57+00:00

[ Upstream commit 4c05ec47384ab3627b62814e8f886e90cc38ce15 ] basechain->stats is rcu protected data which is updated from nft_chain_stats_replace(). This function is executed from the commit phase which holds the pernet nf_tables commit mutex - not the global nfnetlink subsystem mutex. Test commands to reproduce the problem are: %iptables-nft -I INPUT %iptables-nft -Z %iptables-nft -Z This patch uses RCU calls to handle basechain->stats updates to fix a splat that looks like: [89279.358755] ============================= [89279.363656] WARNING: suspicious RCU usage [89279.368458] 4.20.0-rc2+ #44 Tainted: G W L [89279.374661] ----------------------------- [89279.379542] net/netfilter/nf_tables_api.c:1404 suspicious rcu_dereference_protected() usage! [...] [89279.406556] 1 lock held by iptables-nft/5225: [89279.411728] #0: 00000000bf45a000 (&net->nft.commit_mutex){+.+.}, at: nf_tables_valid_genid+0x1f/0x70 [nf_tables] [89279.424022] stack backtrace: [89279.429236] CPU: 0 PID: 5225 Comm: iptables-nft Tainted: G W L 4.20.0-rc2+ #44 [89279.430135] Call Trace: [89279.430135] dump_stack+0xc9/0x16b [89279.430135] ? show_regs_print_info+0x5/0x5 [89279.430135] ? lockdep_rcu_suspicious+0x117/0x160 [89279.430135] nft_chain_commit_update+0x4ea/0x640 [nf_tables] [89279.430135] ? sched_clock_local+0xd4/0x140 [89279.430135] ? check_flags.part.35+0x440/0x440 [89279.430135] ? __rhashtable_remove_fast.constprop.67+0xec0/0xec0 [nf_tables] [89279.430135] ? sched_clock_cpu+0x126/0x170 [89279.430135] ? find_held_lock+0x39/0x1c0 [89279.430135] ? hlock_class+0x140/0x140 [89279.430135] ? is_bpf_text_address+0x5/0xf0 [89279.430135] ? check_flags.part.35+0x440/0x440 [89279.430135] ? __lock_is_held+0xb4/0x140 [89279.430135] nf_tables_commit+0x2555/0x39c0 [nf_tables] Fixes: f102d66b335a4 ("netfilter: nf_tables: use dedicated mutex to guard transactions") Signed-off-by: Taehee Yoo Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin