<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/netfilter/ipset, branch linux-5.9.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>netfilter: ipset: prevent uninit-value in hash_ip6_add</title>
<updated>2020-12-11T12:22:12+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2020-11-19T09:59:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=844fb0454edb19b61a77284f54399cadf264adc8'/>
<id>844fb0454edb19b61a77284f54399cadf264adc8</id>
<content type='text'>
commit 68ad89de918e1c5a79c9c56127e5e31741fd517e upstream.

syzbot found that we are not validating user input properly
before copying 16 bytes [1].

Using NLA_BINARY in ipaddr_policy[] for IPv6 address is not correct,
since it ensures at most 16 bytes were provided.

We should instead make sure user provided exactly 16 bytes.

In old kernels (before v4.20), fix would be to remove the NLA_BINARY,
since NLA_POLICY_EXACT_LEN() was not yet available.

[1]
BUG: KMSAN: uninit-value in hash_ip6_add+0x1cba/0x3a50 net/netfilter/ipset/ip_set_hash_gen.h:892
CPU: 1 PID: 11611 Comm: syz-executor.0 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197
 hash_ip6_add+0x1cba/0x3a50 net/netfilter/ipset/ip_set_hash_gen.h:892
 hash_ip6_uadt+0x976/0xbd0 net/netfilter/ipset/ip_set_hash_ip.c:267
 call_ad+0x329/0xd00 net/netfilter/ipset/ip_set_core.c:1720
 ip_set_ad+0x111f/0x1440 net/netfilter/ipset/ip_set_core.c:1808
 ip_set_uadd+0xf6/0x110 net/netfilter/ipset/ip_set_core.c:1833
 nfnetlink_rcv_msg+0xc7d/0xdf0 net/netfilter/nfnetlink.c:252
 netlink_rcv_skb+0x70a/0x820 net/netlink/af_netlink.c:2494
 nfnetlink_rcv+0x4f0/0x4380 net/netfilter/nfnetlink.c:600
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x11da/0x14b0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x173c/0x1840 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x6d5/0x830 net/socket.c:2440
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45deb9
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fe2e503fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000029ec0 RCX: 000000000045deb9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 000000000169fb7f R14: 00007fe2e50409c0 R15: 000000000118bf2c

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:289
 __msan_chain_origin+0x57/0xa0 mm/kmsan/kmsan_instr.c:147
 ip6_netmask include/linux/netfilter/ipset/pfxlen.h:49 [inline]
 hash_ip6_netmask net/netfilter/ipset/ip_set_hash_ip.c:185 [inline]
 hash_ip6_uadt+0xb1c/0xbd0 net/netfilter/ipset/ip_set_hash_ip.c:263
 call_ad+0x329/0xd00 net/netfilter/ipset/ip_set_core.c:1720
 ip_set_ad+0x111f/0x1440 net/netfilter/ipset/ip_set_core.c:1808
 ip_set_uadd+0xf6/0x110 net/netfilter/ipset/ip_set_core.c:1833
 nfnetlink_rcv_msg+0xc7d/0xdf0 net/netfilter/nfnetlink.c:252
 netlink_rcv_skb+0x70a/0x820 net/netlink/af_netlink.c:2494
 nfnetlink_rcv+0x4f0/0x4380 net/netfilter/nfnetlink.c:600
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x11da/0x14b0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x173c/0x1840 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x6d5/0x830 net/socket.c:2440
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:289
 kmsan_memcpy_memmove_metadata+0x25e/0x2d0 mm/kmsan/kmsan.c:226
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:246
 __msan_memcpy+0x46/0x60 mm/kmsan/kmsan_instr.c:110
 ip_set_get_ipaddr6+0x2cb/0x370 net/netfilter/ipset/ip_set_core.c:310
 hash_ip6_uadt+0x439/0xbd0 net/netfilter/ipset/ip_set_hash_ip.c:255
 call_ad+0x329/0xd00 net/netfilter/ipset/ip_set_core.c:1720
 ip_set_ad+0x111f/0x1440 net/netfilter/ipset/ip_set_core.c:1808
 ip_set_uadd+0xf6/0x110 net/netfilter/ipset/ip_set_core.c:1833
 nfnetlink_rcv_msg+0xc7d/0xdf0 net/netfilter/nfnetlink.c:252
 netlink_rcv_skb+0x70a/0x820 net/netlink/af_netlink.c:2494
 nfnetlink_rcv+0x4f0/0x4380 net/netfilter/nfnetlink.c:600
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x11da/0x14b0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x173c/0x1840 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x6d5/0x830 net/socket.c:2440
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104
 kmsan_slab_alloc+0x8d/0xe0 mm/kmsan/kmsan_hooks.c:76
 slab_alloc_node mm/slub.c:2906 [inline]
 __kmalloc_node_track_caller+0xc61/0x15f0 mm/slub.c:4512
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x309/0xae0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1094 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1176 [inline]
 netlink_sendmsg+0xdb8/0x1840 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x6d5/0x830 net/socket.c:2440
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: a7b4f989a629 ("netfilter: ipset: IP set core support")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Acked-by: Jozsef Kadlecsik &lt;kadlec@netfilter.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 68ad89de918e1c5a79c9c56127e5e31741fd517e upstream.

syzbot found that we are not validating user input properly
before copying 16 bytes [1].

Using NLA_BINARY in ipaddr_policy[] for IPv6 address is not correct,
since it ensures at most 16 bytes were provided.

We should instead make sure user provided exactly 16 bytes.

In old kernels (before v4.20), fix would be to remove the NLA_BINARY,
since NLA_POLICY_EXACT_LEN() was not yet available.

[1]
BUG: KMSAN: uninit-value in hash_ip6_add+0x1cba/0x3a50 net/netfilter/ipset/ip_set_hash_gen.h:892
CPU: 1 PID: 11611 Comm: syz-executor.0 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197
 hash_ip6_add+0x1cba/0x3a50 net/netfilter/ipset/ip_set_hash_gen.h:892
 hash_ip6_uadt+0x976/0xbd0 net/netfilter/ipset/ip_set_hash_ip.c:267
 call_ad+0x329/0xd00 net/netfilter/ipset/ip_set_core.c:1720
 ip_set_ad+0x111f/0x1440 net/netfilter/ipset/ip_set_core.c:1808
 ip_set_uadd+0xf6/0x110 net/netfilter/ipset/ip_set_core.c:1833
 nfnetlink_rcv_msg+0xc7d/0xdf0 net/netfilter/nfnetlink.c:252
 netlink_rcv_skb+0x70a/0x820 net/netlink/af_netlink.c:2494
 nfnetlink_rcv+0x4f0/0x4380 net/netfilter/nfnetlink.c:600
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x11da/0x14b0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x173c/0x1840 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x6d5/0x830 net/socket.c:2440
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45deb9
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fe2e503fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000029ec0 RCX: 000000000045deb9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 000000000169fb7f R14: 00007fe2e50409c0 R15: 000000000118bf2c

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:289
 __msan_chain_origin+0x57/0xa0 mm/kmsan/kmsan_instr.c:147
 ip6_netmask include/linux/netfilter/ipset/pfxlen.h:49 [inline]
 hash_ip6_netmask net/netfilter/ipset/ip_set_hash_ip.c:185 [inline]
 hash_ip6_uadt+0xb1c/0xbd0 net/netfilter/ipset/ip_set_hash_ip.c:263
 call_ad+0x329/0xd00 net/netfilter/ipset/ip_set_core.c:1720
 ip_set_ad+0x111f/0x1440 net/netfilter/ipset/ip_set_core.c:1808
 ip_set_uadd+0xf6/0x110 net/netfilter/ipset/ip_set_core.c:1833
 nfnetlink_rcv_msg+0xc7d/0xdf0 net/netfilter/nfnetlink.c:252
 netlink_rcv_skb+0x70a/0x820 net/netlink/af_netlink.c:2494
 nfnetlink_rcv+0x4f0/0x4380 net/netfilter/nfnetlink.c:600
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x11da/0x14b0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x173c/0x1840 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x6d5/0x830 net/socket.c:2440
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:289
 kmsan_memcpy_memmove_metadata+0x25e/0x2d0 mm/kmsan/kmsan.c:226
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:246
 __msan_memcpy+0x46/0x60 mm/kmsan/kmsan_instr.c:110
 ip_set_get_ipaddr6+0x2cb/0x370 net/netfilter/ipset/ip_set_core.c:310
 hash_ip6_uadt+0x439/0xbd0 net/netfilter/ipset/ip_set_hash_ip.c:255
 call_ad+0x329/0xd00 net/netfilter/ipset/ip_set_core.c:1720
 ip_set_ad+0x111f/0x1440 net/netfilter/ipset/ip_set_core.c:1808
 ip_set_uadd+0xf6/0x110 net/netfilter/ipset/ip_set_core.c:1833
 nfnetlink_rcv_msg+0xc7d/0xdf0 net/netfilter/nfnetlink.c:252
 netlink_rcv_skb+0x70a/0x820 net/netlink/af_netlink.c:2494
 nfnetlink_rcv+0x4f0/0x4380 net/netfilter/nfnetlink.c:600
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x11da/0x14b0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x173c/0x1840 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x6d5/0x830 net/socket.c:2440
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104
 kmsan_slab_alloc+0x8d/0xe0 mm/kmsan/kmsan_hooks.c:76
 slab_alloc_node mm/slub.c:2906 [inline]
 __kmalloc_node_track_caller+0xc61/0x15f0 mm/slub.c:4512
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x309/0xae0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1094 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1176 [inline]
 netlink_sendmsg+0xdb8/0x1840 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x6d5/0x830 net/socket.c:2440
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: a7b4f989a629 ("netfilter: ipset: IP set core support")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Acked-by: Jozsef Kadlecsik &lt;kadlec@netfilter.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: ipset: Update byte and packet counters regardless of whether they match</title>
<updated>2020-11-18T18:22:02+00:00</updated>
<author>
<name>Stefano Brivio</name>
<email>sbrivio@redhat.com</email>
</author>
<published>2020-10-29T15:39:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=66b4345edf0d1f3d2762cfe92cc2bb52ee2b8747'/>
<id>66b4345edf0d1f3d2762cfe92cc2bb52ee2b8747</id>
<content type='text'>
[ Upstream commit 7d10e62c2ff8e084c136c94d32d9a94de4d31248 ]

In ip_set_match_extensions(), for sets with counters, we take care of
updating counters themselves by calling ip_set_update_counter(), and of
checking if the given comparison and values match, by calling
ip_set_match_counter() if needed.

However, if a given comparison on counters doesn't match the configured
values, that doesn't mean the set entry itself isn't matching.

This fix restores the behaviour we had before commit 4750005a85f7
("netfilter: ipset: Fix "don't update counters" mode when counters used
at the matching"), without reintroducing the issue fixed there: back
then, mtype_data_match() first updated counters in any case, and then
took care of matching on counters.

Now, if the IPSET_FLAG_SKIP_COUNTER_UPDATE flag is set,
ip_set_update_counter() will anyway skip counter updates if desired.

The issue observed is illustrated by this reproducer:

  ipset create c hash:ip counters
  ipset add c 192.0.2.1
  iptables -I INPUT -m set --match-set c src --bytes-gt 800 -j DROP

if we now send packets from 192.0.2.1, bytes and packets counters
for the entry as shown by 'ipset list' are always zero, and, no
matter how many bytes we send, the rule will never match, because
counters themselves are not updated.

Reported-by: Mithil Mhatre &lt;mmhatre@redhat.com&gt;
Fixes: 4750005a85f7 ("netfilter: ipset: Fix "don't update counters" mode when counters used at the matching")
Signed-off-by: Stefano Brivio &lt;sbrivio@redhat.com&gt;
Signed-off-by: Jozsef Kadlecsik &lt;kadlec@netfilter.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 7d10e62c2ff8e084c136c94d32d9a94de4d31248 ]

In ip_set_match_extensions(), for sets with counters, we take care of
updating counters themselves by calling ip_set_update_counter(), and of
checking if the given comparison and values match, by calling
ip_set_match_counter() if needed.

However, if a given comparison on counters doesn't match the configured
values, that doesn't mean the set entry itself isn't matching.

This fix restores the behaviour we had before commit 4750005a85f7
("netfilter: ipset: Fix "don't update counters" mode when counters used
at the matching"), without reintroducing the issue fixed there: back
then, mtype_data_match() first updated counters in any case, and then
took care of matching on counters.

Now, if the IPSET_FLAG_SKIP_COUNTER_UPDATE flag is set,
ip_set_update_counter() will anyway skip counter updates if desired.

The issue observed is illustrated by this reproducer:

  ipset create c hash:ip counters
  ipset add c 192.0.2.1
  iptables -I INPUT -m set --match-set c src --bytes-gt 800 -j DROP

if we now send packets from 192.0.2.1, bytes and packets counters
for the entry as shown by 'ipset list' are always zero, and, no
matter how many bytes we send, the rule will never match, because
counters themselves are not updated.

Reported-by: Mithil Mhatre &lt;mmhatre@redhat.com&gt;
Fixes: 4750005a85f7 ("netfilter: ipset: Fix "don't update counters" mode when counters used at the matching")
Signed-off-by: Stefano Brivio &lt;sbrivio@redhat.com&gt;
Signed-off-by: Jozsef Kadlecsik &lt;kadlec@netfilter.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: Use fallthrough pseudo-keyword</title>
<updated>2020-07-21T23:18:05+00:00</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavoars@kernel.org</email>
</author>
<published>2020-07-08T20:09:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=954d82979b2f9dd4c20b895226799650d4841b94'/>
<id>954d82979b2f9dd4c20b895226799650d4841b94</id>
<content type='text'>
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: ipset: call ip_set_free() instead of kfree()</title>
<updated>2020-06-30T17:09:56+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2020-06-30T00:04:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c4e8fa9074ad94f80e5c0dcaa16b313e50e958c5'/>
<id>c4e8fa9074ad94f80e5c0dcaa16b313e50e958c5</id>
<content type='text'>
Whenever ip_set_alloc() is used, allocated memory can either
use kmalloc() or vmalloc(). We should call kvfree() or
ip_set_free()

invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 21935 Comm: syz-executor.3 Not tainted 5.8.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__phys_addr+0xa7/0x110 arch/x86/mm/physaddr.c:28
Code: 1d 7a 09 4c 89 e3 31 ff 48 d3 eb 48 89 de e8 d0 58 3f 00 48 85 db 75 0d e8 26 5c 3f 00 4c 89 e0 5b 5d 41 5c c3 e8 19 5c 3f 00 &lt;0f&gt; 0b e8 12 5c 3f 00 48 c7 c0 10 10 a8 89 48 ba 00 00 00 00 00 fc
RSP: 0000:ffffc900018572c0 EFLAGS: 00010046
RAX: 0000000000040000 RBX: 0000000000000001 RCX: ffffc9000fac3000
RDX: 0000000000040000 RSI: ffffffff8133f437 RDI: 0000000000000007
RBP: ffffc90098aff000 R08: 0000000000000000 R09: ffff8880ae636cdb
R10: 0000000000000000 R11: 0000000000000000 R12: 0000408018aff000
R13: 0000000000080000 R14: 000000000000001d R15: ffffc900018573d8
FS:  00007fc540c66700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc9dcd67200 CR3: 0000000059411000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 virt_to_head_page include/linux/mm.h:841 [inline]
 virt_to_cache mm/slab.h:474 [inline]
 kfree+0x77/0x2c0 mm/slab.c:3749
 hash_net_create+0xbb2/0xd70 net/netfilter/ipset/ip_set_hash_gen.h:1536
 ip_set_create+0x6a2/0x13c0 net/netfilter/ipset/ip_set_core.c:1128
 nfnetlink_rcv_msg+0xbe8/0xea0 net/netfilter/nfnetlink.c:230
 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469
 nfnetlink_rcv+0x1ac/0x420 net/netfilter/nfnetlink.c:564
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2352
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2406
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb19
Code: Bad RIP value.
RSP: 002b:00007fc540c65c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004fed80 RCX: 000000000045cb19
RDX: 0000000000000000 RSI: 0000000020001080 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000095e R14: 00000000004cc295 R15: 00007fc540c666d4

Fixes: f66ee0410b1c ("netfilter: ipset: Fix "INFO: rcu detected stall in hash_xxx" reports")
Fixes: 03c8b234e61a ("netfilter: ipset: Generalize extensions support")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Whenever ip_set_alloc() is used, allocated memory can either
use kmalloc() or vmalloc(). We should call kvfree() or
ip_set_free()

invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 21935 Comm: syz-executor.3 Not tainted 5.8.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__phys_addr+0xa7/0x110 arch/x86/mm/physaddr.c:28
Code: 1d 7a 09 4c 89 e3 31 ff 48 d3 eb 48 89 de e8 d0 58 3f 00 48 85 db 75 0d e8 26 5c 3f 00 4c 89 e0 5b 5d 41 5c c3 e8 19 5c 3f 00 &lt;0f&gt; 0b e8 12 5c 3f 00 48 c7 c0 10 10 a8 89 48 ba 00 00 00 00 00 fc
RSP: 0000:ffffc900018572c0 EFLAGS: 00010046
RAX: 0000000000040000 RBX: 0000000000000001 RCX: ffffc9000fac3000
RDX: 0000000000040000 RSI: ffffffff8133f437 RDI: 0000000000000007
RBP: ffffc90098aff000 R08: 0000000000000000 R09: ffff8880ae636cdb
R10: 0000000000000000 R11: 0000000000000000 R12: 0000408018aff000
R13: 0000000000080000 R14: 000000000000001d R15: ffffc900018573d8
FS:  00007fc540c66700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc9dcd67200 CR3: 0000000059411000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 virt_to_head_page include/linux/mm.h:841 [inline]
 virt_to_cache mm/slab.h:474 [inline]
 kfree+0x77/0x2c0 mm/slab.c:3749
 hash_net_create+0xbb2/0xd70 net/netfilter/ipset/ip_set_hash_gen.h:1536
 ip_set_create+0x6a2/0x13c0 net/netfilter/ipset/ip_set_core.c:1128
 nfnetlink_rcv_msg+0xbe8/0xea0 net/netfilter/nfnetlink.c:230
 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469
 nfnetlink_rcv+0x1ac/0x420 net/netfilter/nfnetlink.c:564
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2352
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2406
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb19
Code: Bad RIP value.
RSP: 002b:00007fc540c65c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004fed80 RCX: 000000000045cb19
RDX: 0000000000000000 RSI: 0000000020001080 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000095e R14: 00000000004cc295 R15: 00007fc540c666d4

Fixes: f66ee0410b1c ("netfilter: ipset: Fix "INFO: rcu detected stall in hash_xxx" reports")
Fixes: 03c8b234e61a ("netfilter: ipset: Generalize extensions support")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: ipset: fix unaligned atomic access</title>
<updated>2020-06-24T22:49:48+00:00</updated>
<author>
<name>Russell King</name>
<email>rmk+kernel@armlinux.org.uk</email>
</author>
<published>2020-06-10T20:51:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=715028460082d07a7ec6fcd87b14b46784346a72'/>
<id>715028460082d07a7ec6fcd87b14b46784346a72</id>
<content type='text'>
When using ip_set with counters and comment, traffic causes the kernel
to panic on 32-bit ARM:

Alignment trap: not handling instruction e1b82f9f at [&lt;bf01b0dc&gt;]
Unhandled fault: alignment exception (0x221) at 0xea08133c
PC is at ip_set_match_extensions+0xe0/0x224 [ip_set]

The problem occurs when we try to update the 64-bit counters - the
faulting address above is not 64-bit aligned.  The problem occurs
due to the way elements are allocated, for example:

	set-&gt;dsize = ip_set_elem_len(set, tb, 0, 0);
	map = ip_set_alloc(sizeof(*map) + elements * set-&gt;dsize);

If the element has a requirement for a member to be 64-bit aligned,
and set-&gt;dsize is not a multiple of 8, but is a multiple of four,
then every odd numbered elements will be misaligned - and hitting
an atomic64_add() on that element will cause the kernel to panic.

ip_set_elem_len() must return a size that is rounded to the maximum
alignment of any extension field stored in the element.  This change
ensures that is the case.

Fixes: 95ad1f4a9358 ("netfilter: ipset: Fix extension alignment")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Acked-by: Jozsef Kadlecsik &lt;kadlec@netfilter.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When using ip_set with counters and comment, traffic causes the kernel
to panic on 32-bit ARM:

Alignment trap: not handling instruction e1b82f9f at [&lt;bf01b0dc&gt;]
Unhandled fault: alignment exception (0x221) at 0xea08133c
PC is at ip_set_match_extensions+0xe0/0x224 [ip_set]

The problem occurs when we try to update the 64-bit counters - the
faulting address above is not 64-bit aligned.  The problem occurs
due to the way elements are allocated, for example:

	set-&gt;dsize = ip_set_elem_len(set, tb, 0, 0);
	map = ip_set_alloc(sizeof(*map) + elements * set-&gt;dsize);

If the element has a requirement for a member to be 64-bit aligned,
and set-&gt;dsize is not a multiple of 8, but is a multiple of four,
then every odd numbered elements will be misaligned - and hitting
an atomic64_add() on that element will cause the kernel to panic.

ip_set_elem_len() must return a size that is rounded to the maximum
alignment of any extension field stored in the element.  This change
ensures that is the case.

Fixes: 95ad1f4a9358 ("netfilter: ipset: Fix extension alignment")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Acked-by: Jozsef Kadlecsik &lt;kadlec@netfilter.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: ipset: Fix subcounter update skip</title>
<updated>2020-05-25T18:39:14+00:00</updated>
<author>
<name>Phil Sutter</name>
<email>phil@nwl.cc</email>
</author>
<published>2020-05-14T11:31:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a164b95ad6055c50612795882f35e0efda1f1390'/>
<id>a164b95ad6055c50612795882f35e0efda1f1390</id>
<content type='text'>
If IPSET_FLAG_SKIP_SUBCOUNTER_UPDATE is set, user requested to not
update counters in sub sets. Therefore IPSET_FLAG_SKIP_COUNTER_UPDATE
must be set, not unset.

Fixes: 6e01781d1c80e ("netfilter: ipset: set match: add support to match the counters")
Signed-off-by: Phil Sutter &lt;phil@nwl.cc&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If IPSET_FLAG_SKIP_SUBCOUNTER_UPDATE is set, user requested to not
update counters in sub sets. Therefore IPSET_FLAG_SKIP_COUNTER_UPDATE
must be set, not unset.

Fixes: 6e01781d1c80e ("netfilter: ipset: set match: add support to match the counters")
Signed-off-by: Phil Sutter &lt;phil@nwl.cc&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: ipset: Pass lockdep expression to RCU lists</title>
<updated>2020-04-06T12:31:25+00:00</updated>
<author>
<name>Amol Grover</name>
<email>frextrite@gmail.com</email>
</author>
<published>2020-02-16T17:26:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b135fc0801b671c50de103572b819bcd41603613'/>
<id>b135fc0801b671c50de103572b819bcd41603613</id>
<content type='text'>
ip_set_type_list is traversed using list_for_each_entry_rcu
outside an RCU read-side critical section but under the protection
of ip_set_type_mutex.

Hence, add corresponding lockdep expression to silence false-positive
warnings, and harden RCU lists.

Signed-off-by: Amol Grover &lt;frextrite@gmail.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
ip_set_type_list is traversed using list_for_each_entry_rcu
outside an RCU read-side critical section but under the protection
of ip_set_type_mutex.

Hence, add corresponding lockdep expression to silence false-positive
warnings, and harden RCU lists.

Signed-off-by: Amol Grover &lt;frextrite@gmail.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: Replace zero-length array with flexible-array member</title>
<updated>2020-03-15T14:20:16+00:00</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavo@embeddedor.com</email>
</author>
<published>2020-02-20T13:59:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6daf14140129d30207ed6a0a69851fa6a3636bda'/>
<id>6daf14140129d30207ed6a0a69851fa6a3636bda</id>
<content type='text'>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

Lastly, fix checkpatch.pl warning
WARNING: __aligned(size) is preferred over __attribute__((aligned(size)))
in net/bridge/netfilter/ebtables.c

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva &lt;gustavo@embeddedor.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

Lastly, fix checkpatch.pl warning
WARNING: __aligned(size) is preferred over __attribute__((aligned(size)))
in net/bridge/netfilter/ebtables.c

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva &lt;gustavo@embeddedor.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: ipset: Fix forceadd evaluation path</title>
<updated>2020-02-22T11:13:45+00:00</updated>
<author>
<name>Jozsef Kadlecsik</name>
<email>kadlec@netfilter.org</email>
</author>
<published>2020-02-22T11:01:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8af1c6fbd9239877998c7f5a591cb2c88d41fb66'/>
<id>8af1c6fbd9239877998c7f5a591cb2c88d41fb66</id>
<content type='text'>
When the forceadd option is enabled, the hash:* types should find and replace
the first entry in the bucket with the new one if there are no reuseable
(deleted or timed out) entries. However, the position index was just not set
to zero and remained the invalid -1 if there were no reuseable entries.

Reported-by: syzbot+6a86565c74ebe30aea18@syzkaller.appspotmail.com
Fixes: 23c42a403a9c ("netfilter: ipset: Introduction of new commands and protocol version 7")
Signed-off-by: Jozsef Kadlecsik &lt;kadlec@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When the forceadd option is enabled, the hash:* types should find and replace
the first entry in the bucket with the new one if there are no reuseable
(deleted or timed out) entries. However, the position index was just not set
to zero and remained the invalid -1 if there were no reuseable entries.

Reported-by: syzbot+6a86565c74ebe30aea18@syzkaller.appspotmail.com
Fixes: 23c42a403a9c ("netfilter: ipset: Introduction of new commands and protocol version 7")
Signed-off-by: Jozsef Kadlecsik &lt;kadlec@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: ipset: Fix "INFO: rcu detected stall in hash_xxx" reports</title>
<updated>2020-02-22T11:00:06+00:00</updated>
<author>
<name>Jozsef Kadlecsik</name>
<email>kadlec@netfilter.org</email>
</author>
<published>2020-02-11T22:20:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f66ee0410b1c3481ee75e5db9b34547b4d582465'/>
<id>f66ee0410b1c3481ee75e5db9b34547b4d582465</id>
<content type='text'>
In the case of huge hash:* types of sets, due to the single spinlock of
a set the processing of the whole set under spinlock protection could take
too long.

There were four places where the whole hash table of the set was processed
from bucket to bucket under holding the spinlock:

- During resizing a set, the original set was locked to exclude kernel side
  add/del element operations (userspace add/del is excluded by the
  nfnetlink mutex). The original set is actually just read during the
  resize, so the spinlocking is replaced with rcu locking of regions.
  However, thus there can be parallel kernel side add/del of entries.
  In order not to loose those operations a backlog is added and replayed
  after the successful resize.
- Garbage collection of timed out entries was also protected by the spinlock.
  In order not to lock too long, region locking is introduced and a single
  region is processed in one gc go. Also, the simple timer based gc running
  is replaced with a workqueue based solution. The internal book-keeping
  (number of elements, size of extensions) is moved to region level due to
  the region locking.
- Adding elements: when the max number of the elements is reached, the gc
  was called to evict the timed out entries. The new approach is that the gc
  is called just for the matching region, assuming that if the region
  (proportionally) seems to be full, then the whole set does. We could scan
  the other regions to check every entry under rcu locking, but for huge
  sets it'd mean a slowdown at adding elements.
- Listing the set header data: when the set was defined with timeout
  support, the garbage collector was called to clean up timed out entries
  to get the correct element numbers and set size values. Now the set is
  scanned to check non-timed out entries, without actually calling the gc
  for the whole set.

Thanks to Florian Westphal for helping me to solve the SOFTIRQ-safe -&gt;
SOFTIRQ-unsafe lock order issues during working on the patch.

Reported-by: syzbot+4b0e9d4ff3cf117837e5@syzkaller.appspotmail.com
Reported-by: syzbot+c27b8d5010f45c666ed1@syzkaller.appspotmail.com
Reported-by: syzbot+68a806795ac89df3aa1c@syzkaller.appspotmail.com
Fixes: 23c42a403a9c ("netfilter: ipset: Introduction of new commands and protocol version 7")
Signed-off-by: Jozsef Kadlecsik &lt;kadlec@netfilter.org&gt;
</content>
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<pre>
In the case of huge hash:* types of sets, due to the single spinlock of
a set the processing of the whole set under spinlock protection could take
too long.

There were four places where the whole hash table of the set was processed
from bucket to bucket under holding the spinlock:

- During resizing a set, the original set was locked to exclude kernel side
  add/del element operations (userspace add/del is excluded by the
  nfnetlink mutex). The original set is actually just read during the
  resize, so the spinlocking is replaced with rcu locking of regions.
  However, thus there can be parallel kernel side add/del of entries.
  In order not to loose those operations a backlog is added and replayed
  after the successful resize.
- Garbage collection of timed out entries was also protected by the spinlock.
  In order not to lock too long, region locking is introduced and a single
  region is processed in one gc go. Also, the simple timer based gc running
  is replaced with a workqueue based solution. The internal book-keeping
  (number of elements, size of extensions) is moved to region level due to
  the region locking.
- Adding elements: when the max number of the elements is reached, the gc
  was called to evict the timed out entries. The new approach is that the gc
  is called just for the matching region, assuming that if the region
  (proportionally) seems to be full, then the whole set does. We could scan
  the other regions to check every entry under rcu locking, but for huge
  sets it'd mean a slowdown at adding elements.
- Listing the set header data: when the set was defined with timeout
  support, the garbage collector was called to clean up timed out entries
  to get the correct element numbers and set size values. Now the set is
  scanned to check non-timed out entries, without actually calling the gc
  for the whole set.

Thanks to Florian Westphal for helping me to solve the SOFTIRQ-safe -&gt;
SOFTIRQ-unsafe lock order issues during working on the patch.

Reported-by: syzbot+4b0e9d4ff3cf117837e5@syzkaller.appspotmail.com
Reported-by: syzbot+c27b8d5010f45c666ed1@syzkaller.appspotmail.com
Reported-by: syzbot+68a806795ac89df3aa1c@syzkaller.appspotmail.com
Fixes: 23c42a403a9c ("netfilter: ipset: Introduction of new commands and protocol version 7")
Signed-off-by: Jozsef Kadlecsik &lt;kadlec@netfilter.org&gt;
</pre>
</div>
</content>
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