kernel/net/netfilter, branch linux-5.1.y

net: make skb_dst_force return true when dst is refcounted

2019-07-28T06:28:27Z

[ Upstream commit b60a77386b1d4868f72f6353d35dabe5fbe981f2 ] netfilter did not expect that skb_dst_force() can cause skb to lose its dst entry. I got a bug report with a skb->dst NULL dereference in netfilter output path. The backtrace contains nf_reinject(), so the dst might have been cleared when skb got queued to userspace. Other users were fixed via if (skb_dst(skb)) { skb_dst_force(skb); if (!skb_dst(skb)) goto handle_err; } But I think its preferable to make the 'dst might be cleared' part of the function explicit. In netfilter case, skb with a null dst is expected when queueing in prerouting hook, so drop skb for the other hooks. v2: v1 of this patch returned true in case skb had no dst entry. Eric said: Say if we have two skb_dst_force() calls for some reason on the same skb, only the first one will return false. This now returns false even when skb had no dst, as per Erics suggestion, so callers might need to check skb_dst() first before skb_dst_force(). Signed-off-by: Florian Westphal Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

netfilter: Fix remainder of pseudo-header protocol 0

2019-07-26T07:12:47Z

[ Upstream commit 5d1549847c76b1ffcf8e388ef4d0f229bdd1d7e8 ] Since v5.1-rc1, some types of packets do not get unreachable reply with the following iptables setting. Fox example, $ iptables -A INPUT -p icmp --icmp-type 8 -j REJECT $ ping 127.0.0.1 -c 1 PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data. — 127.0.0.1 ping statistics — 1 packets transmitted, 0 received, 100% packet loss, time 0ms We should have got the following reply from command line, but we did not. From 127.0.0.1 icmp_seq=1 Destination Port Unreachable Yi Zhao reported it and narrowed it down to: 7fc38225363d ("netfilter: reject: skip csum verification for protocols that don't support it"), This is because nf_ip_checksum still expects pseudo-header protocol type 0 for packets that are of neither TCP or UDP, and thus ICMP packets are mistakenly treated as TCP/UDP. This patch corrects the conditions in nf_ip_checksum and all other places that still call it with protocol 0. Fixes: 7fc38225363d ("netfilter: reject: skip csum verification for protocols that don't support it") Reported-by: Yi Zhao Signed-off-by: He Zhe Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: ctnetlink: Fix regression in conntrack entry deletion

2019-07-26T07:12:43Z

[ Upstream commit e7600865db32b69deb0109b8254244dca592adcf ] Commit f8e608982022 ("netfilter: ctnetlink: Resolve conntrack L3-protocol flush regression") introduced a regression in which deletion of conntrack entries would fail because the L3 protocol information is replaced by AF_UNSPEC. As a result the search for the entry to be deleted would turn up empty due to the tuple used to perform the search is now different from the tuple used to initially set up the entry. For flushing the conntrack table we do however want to keep the option for nfgenmsg->version to have a non-zero value to allow for newer user-space tools to request treatment under the new behavior. With that it is possible to independently flush tables for a defined L3 protocol. This was introduced with the enhancements in in commit 59c08c69c278 ("netfilter: ctnetlink: Support L3 protocol-filter on flush"). Older user-space tools will retain the behavior of flushing all tables regardless of defined L3 protocol. Fixes: f8e608982022 ("netfilter: ctnetlink: Resolve conntrack L3-protocol flush regression") Suggested-by: Pablo Neira Ayuso Signed-off-by: Felix Kaechele Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

ipvs: fix tinfo memory leak in start_sync_thread

2019-07-26T07:12:42Z

[ Upstream commit 5db7c8b9f9fc2aeec671ae3ca6375752c162e0e7 ] syzkaller reports for memory leak in start_sync_thread [1] As Eric points out, kthread may start and stop before the threadfn function is called, so there is no chance the data (tinfo in our case) to be released in thread. Fix this by releasing tinfo in the controlling code instead. [1] BUG: memory leak unreferenced object 0xffff8881206bf700 (size 32): comm "syz-executor761", pid 7268, jiffies 4294943441 (age 20.470s) hex dump (first 32 bytes): 00 40 7c 09 81 88 ff ff 80 45 b8 21 81 88 ff ff .@|......E.!.... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<0000000057619e23>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline] [<0000000057619e23>] slab_post_alloc_hook mm/slab.h:439 [inline] [<0000000057619e23>] slab_alloc mm/slab.c:3326 [inline] [<0000000057619e23>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 [<0000000086ce5479>] kmalloc include/linux/slab.h:547 [inline] [<0000000086ce5479>] start_sync_thread+0x5d2/0xe10 net/netfilter/ipvs/ip_vs_sync.c:1862 [<000000001a9229cc>] do_ip_vs_set_ctl+0x4c5/0x780 net/netfilter/ipvs/ip_vs_ctl.c:2402 [<00000000ece457c8>] nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] [<00000000ece457c8>] nf_setsockopt+0x4c/0x80 net/netfilter/nf_sockopt.c:115 [<00000000942f62d4>] ip_setsockopt net/ipv4/ip_sockglue.c:1258 [inline] [<00000000942f62d4>] ip_setsockopt+0x9b/0xb0 net/ipv4/ip_sockglue.c:1238 [<00000000a56a8ffd>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616 [<00000000fa895401>] sock_common_setsockopt+0x38/0x50 net/core/sock.c:3130 [<0000000095eef4cf>] __sys_setsockopt+0x98/0x120 net/socket.c:2078 [<000000009747cf88>] __do_sys_setsockopt net/socket.c:2089 [inline] [<000000009747cf88>] __se_sys_setsockopt net/socket.c:2086 [inline] [<000000009747cf88>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086 [<00000000ded8ba80>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301 [<00000000893b4ac8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported-by: syzbot+7e2e50c8adfccd2e5041@syzkaller.appspotmail.com Suggested-by: Eric Biggers Fixes: 998e7a76804b ("ipvs: Use kthread_run() instead of doing a double-fork via kernel_thread()") Signed-off-by: Julian Anastasov Acked-by: Simon Horman Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

ipvs: defer hook registration to avoid leaks

2019-07-26T07:12:39Z

[ Upstream commit cf47a0b882a4e5f6b34c7949d7b293e9287f1972 ] syzkaller reports for memory leak when registering hooks [1] As we moved the nf_unregister_net_hooks() call into __ip_vs_dev_cleanup(), defer the nf_register_net_hooks() call, so that hooks are allocated and freed from same pernet_operations (ipvs_core_dev_ops). [1] BUG: memory leak unreferenced object 0xffff88810acd8a80 (size 96): comm "syz-executor073", pid 7254, jiffies 4294950560 (age 22.250s) hex dump (first 32 bytes): 02 00 00 00 00 00 00 00 50 8b bb 82 ff ff ff ff ........P....... 00 00 00 00 00 00 00 00 00 77 bb 82 ff ff ff ff .........w...... backtrace: [<0000000013db61f1>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline] [<0000000013db61f1>] slab_post_alloc_hook mm/slab.h:439 [inline] [<0000000013db61f1>] slab_alloc_node mm/slab.c:3269 [inline] [<0000000013db61f1>] kmem_cache_alloc_node_trace+0x15b/0x2a0 mm/slab.c:3597 [<000000001a27307d>] __do_kmalloc_node mm/slab.c:3619 [inline] [<000000001a27307d>] __kmalloc_node+0x38/0x50 mm/slab.c:3627 [<0000000025054add>] kmalloc_node include/linux/slab.h:590 [inline] [<0000000025054add>] kvmalloc_node+0x4a/0xd0 mm/util.c:431 [<0000000050d1bc00>] kvmalloc include/linux/mm.h:637 [inline] [<0000000050d1bc00>] kvzalloc include/linux/mm.h:645 [inline] [<0000000050d1bc00>] allocate_hook_entries_size+0x3b/0x60 net/netfilter/core.c:61 [<00000000e8abe142>] nf_hook_entries_grow+0xae/0x270 net/netfilter/core.c:128 [<000000004b94797c>] __nf_register_net_hook+0x9a/0x170 net/netfilter/core.c:337 [<00000000d1545cbc>] nf_register_net_hook+0x34/0xc0 net/netfilter/core.c:464 [<00000000876c9b55>] nf_register_net_hooks+0x53/0xc0 net/netfilter/core.c:480 [<000000002ea868e0>] __ip_vs_init+0xe8/0x170 net/netfilter/ipvs/ip_vs_core.c:2280 [<000000002eb2d451>] ops_init+0x4c/0x140 net/core/net_namespace.c:130 [<000000000284ec48>] setup_net+0xde/0x230 net/core/net_namespace.c:316 [<00000000a70600fa>] copy_net_ns+0xf0/0x1e0 net/core/net_namespace.c:439 [<00000000ff26c15e>] create_new_namespaces+0x141/0x2a0 kernel/nsproxy.c:107 [<00000000b103dc79>] copy_namespaces+0xa1/0xe0 kernel/nsproxy.c:165 [<000000007cc008a2>] copy_process.part.0+0x11fd/0x2150 kernel/fork.c:2035 [<00000000c344af7c>] copy_process kernel/fork.c:1800 [inline] [<00000000c344af7c>] _do_fork+0x121/0x4f0 kernel/fork.c:2369 Reported-by: syzbot+722da59ccb264bc19910@syzkaller.appspotmail.com Fixes: 719c7d563c17 ("ipvs: Fix use-after-free in ip_vs_in") Signed-off-by: Julian Anastasov Acked-by: Simon Horman Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

ipset: Fix memory accounting for hash types on resize

2019-07-26T07:12:32Z

[ Upstream commit 11921796f4799ca9c61c4b22cc54d84aa69f8a35 ] If a fresh array block is allocated during resize, the current in-memory set size should be increased by the size of the block, not replaced by it. Before the fix, adding entries to a hash set type, leading to a table resize, caused an inconsistent memory size to be reported. This becomes more obvious when swapping sets with similar sizes: # cat hash_ip_size.sh #!/bin/sh FAIL_RETRIES=10 tries=0 while [ ${tries} -lt ${FAIL_RETRIES} ]; do ipset create t1 hash:ip for i in `seq 1 4345`; do ipset add t1 1.2.$((i / 255)).$((i % 255)) done t1_init="$(ipset list t1|sed -n 's/Size in memory: $.*$/\1/p')" ipset create t2 hash:ip for i in `seq 1 4360`; do ipset add t2 1.2.$((i / 255)).$((i % 255)) done t2_init="$(ipset list t2|sed -n 's/Size in memory: $.*$/\1/p')" ipset swap t1 t2 t1_swap="$(ipset list t1|sed -n 's/Size in memory: $.*$/\1/p')" t2_swap="$(ipset list t2|sed -n 's/Size in memory: $.*$/\1/p')" ipset destroy t1 ipset destroy t2 tries=$((tries + 1)) if [ ${t1_init} -lt 10000 ] || [ ${t2_init} -lt 10000 ]; then echo "FAIL after ${tries} tries:" echo "T1 size ${t1_init}, after swap ${t1_swap}" echo "T2 size ${t2_init}, after swap ${t2_swap}" exit 1 fi done echo "PASS" # echo -n 'func hash_ip4_resize +p' > /sys/kernel/debug/dynamic_debug/control # ./hash_ip_size.sh [ 2035.018673] attempt to resize set t1 from 10 to 11, t 00000000fe6551fa [ 2035.078583] set t1 resized from 10 (00000000fe6551fa) to 11 (00000000172a0163) [ 2035.080353] Table destroy by resize 00000000fe6551fa FAIL after 4 tries: T1 size 9064, after swap 71128 T2 size 71128, after swap 9064 Reported-by: NOYB Fixes: 9e41f26a505c ("netfilter: ipset: Count non-static extension memory for userspace") Signed-off-by: Stefano Brivio Signed-off-by: Jozsef Kadlecsik Signed-off-by: Sasha Levin

netfilter: nft_flow_offload: IPCB is only valid for ipv4 family

2019-07-10T07:52:21Z

commit 69aeb538587e087bfc81dd1f465eab3558ff3158 upstream. Guard this with a check vs. ipv4, IPCB isn't valid in ipv6 case. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: nft_flow_offload: don't offload when sequence numbers need adjustment

2019-07-10T07:52:21Z

commit 91a9048f238063dde7feea752b9dd386f7e3808b upstream. We can't deal with tcp sequence number rewrite in flow_offload. While at it, simplify helper check, we only need to know if the extension is present, we don't need the helper data. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: nft_flow_offload: set liberal tracking mode for tcp

2019-07-10T07:52:20Z

commit 8437a6209f76f85a2db1abb12a9bde2170801617 upstream. Without it, whenever a packet has to be pushed up the stack (e.g. because of mtu mismatch), then conntrack will flag packets as invalid, which in turn breaks NAT. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: nf_flow_table: ignore DF bit setting

2019-07-10T07:52:20Z

commit e75b3e1c9bc5b997d09bdf8eb72ab3dd3c1a7072 upstream. Its irrelevant if the DF bit is set or not, we must pass packet to stack in either case. If the DF bit is set, we must pass it to stack so the appropriate ICMP error can be generated. If the DF is not set, we must pass it to stack for fragmentation. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman