linux/net/netfilter, branch v5.0

ipvs: fix warning on unused variable

2019-02-16T09:41:42Z

When CONFIG_IP_VS_IPV6 is not defined, build produced this warning: net/netfilter/ipvs/ip_vs_ctl.c:899:6: warning: unused variable ‘ret’ [-Wunused-variable] int ret = 0; ^~~ Fix this by moving the declaration of 'ret' in the CONFIG_IP_VS_IPV6 section in the same function. While at it, drop its unneeded initialisation. Fixes: 098e13f5b21d ("ipvs: fix dependency on nf_defrag_ipv6") Reported-by: Stefano Brivio Signed-off-by: Andrea Claudi Reviewed-by: Stefano Brivio Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: fix flush after rule deletion in the same batch

2019-02-15T14:32:32Z

Flush after rule deletion bogusly hits -ENOENT. Skip rules that have been already from nft_delrule_by_chain() which is always called from the flush path. Fixes: cf9dc09d0949 ("netfilter: nf_tables: fix missing rules flushing per table") Reported-by: Phil Sutter Acked-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso

netfilter: nft_compat: use-after-free when deleting targets

2019-02-13T17:14:54Z

Fetch pointer to module before target object is released. Fixes: 29e3880109e3 ("netfilter: nf_tables: fix use-after-free when deleting compat expressions") Fixes: 0ca743a55991 ("netfilter: nf_tables: add compatibility layer for x_tables") Signed-off-by: Pablo Neira Ayuso

ipvs: fix dependency on nf_defrag_ipv6

2019-02-12T10:24:01Z

ipvs relies on nf_defrag_ipv6 module to manage IPv6 fragmentation, but lacks proper Kconfig dependencies and does not explicitly request defrag features. As a result, if netfilter hooks are not loaded, when IPv6 fragmented packet are handled by ipvs only the first fragment makes through. Fix it properly declaring the dependency on Kconfig and registering netfilter hooks on ip_vs_add_service() and ip_vs_new_dest(). Reported-by: Li Shuang Signed-off-by: Andrea Claudi Acked-by: Julian Anastasov Acked-by: Simon Horman Signed-off-by: Pablo Neira Ayuso

netfilter: compat: initialize all fields in xt_init

2019-02-11T23:35:18Z

If a non zero value happens to be in xt[NFPROTO_BRIDGE].cur at init time, the following panic can be caused by running % ebtables -t broute -F BROUTING from a 32-bit user level on a 64-bit kernel. This patch replaces kmalloc_array with kcalloc when allocating xt. [ 474.680846] BUG: unable to handle kernel paging request at 0000000009600920 [ 474.687869] PGD 2037006067 P4D 2037006067 PUD 2038938067 PMD 0 [ 474.693838] Oops: 0000 [#1] SMP [ 474.697055] CPU: 9 PID: 4662 Comm: ebtables Kdump: loaded Not tainted 4.19.17-11302235.AroraKernelnext.fc18.x86_64 #1 [ 474.707721] Hardware name: Supermicro X9DRT/X9DRT, BIOS 3.0 06/28/2013 [ 474.714313] RIP: 0010:xt_compat_calc_jump+0x2f/0x63 [x_tables] [ 474.720201] Code: 40 0f b6 ff 55 31 c0 48 6b ff 70 48 03 3d dc 45 00 00 48 89 e5 8b 4f 6c 4c 8b 47 60 ff c9 39 c8 7f 2f 8d 14 08 d1 fa 48 63 fa <41> 39 34 f8 4c 8d 0c fd 00 00 00 00 73 05 8d 42 01 eb e1 76 05 8d [ 474.739023] RSP: 0018:ffffc9000943fc58 EFLAGS: 00010207 [ 474.744296] RAX: 0000000000000000 RBX: ffffc90006465000 RCX: 0000000002580249 [ 474.751485] RDX: 00000000012c0124 RSI: fffffffff7be17e9 RDI: 00000000012c0124 [ 474.758670] RBP: ffffc9000943fc58 R08: 0000000000000000 R09: ffffffff8117cf8f [ 474.765855] R10: ffffc90006477000 R11: 0000000000000000 R12: 0000000000000001 [ 474.773048] R13: 0000000000000000 R14: ffffc9000943fcb8 R15: ffffc9000943fcb8 [ 474.780234] FS: 0000000000000000(0000) GS:ffff88a03f840000(0063) knlGS:00000000f7ac7700 [ 474.788612] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 474.794632] CR2: 0000000009600920 CR3: 0000002037422006 CR4: 00000000000606e0 [ 474.802052] Call Trace: [ 474.804789] compat_do_replace+0x1fb/0x2a3 [ebtables] [ 474.810105] compat_do_ebt_set_ctl+0x69/0xe6 [ebtables] [ 474.815605] ? try_module_get+0x37/0x42 [ 474.819716] compat_nf_setsockopt+0x4f/0x6d [ 474.824172] compat_ip_setsockopt+0x7e/0x8c [ 474.828641] compat_raw_setsockopt+0x16/0x3a [ 474.833220] compat_sock_common_setsockopt+0x1d/0x24 [ 474.838458] __compat_sys_setsockopt+0x17e/0x1b1 [ 474.843343] ? __check_object_size+0x76/0x19a [ 474.847960] __ia32_compat_sys_socketcall+0x1cb/0x25b [ 474.853276] do_fast_syscall_32+0xaf/0xf6 [ 474.857548] entry_SYSENTER_compat+0x6b/0x7a Signed-off-by: Francesco Ruggeri Acked-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: nft_compat: don't use refcount_inc on newly allocated entry

2019-02-05T13:10:33Z

When I moved the refcount to refcount_t type I missed the fact that refcount_inc() will result in use-after-free warning with CONFIG_REFCOUNT_FULL=y builds. The correct fix would be to init the reference count to 1 at allocation time, but, unfortunately we cannot do this, as we can't undo that in case something else fails later in the batch. So only solution I see is to special-case the 'new entry' condition and replace refcount_inc() with a "delayed" refcount_set(1) in this case, as done here. The .activate callback can be removed to simplify things, we only need to make sure that deactivate() decrements/unlinks the entry from the list at end of transaction phase (commit or abort). Fixes: 12c44aba6618 ("netfilter: nft_compat: use refcnt_t type for nft_xt reference count") Reported-by: Jordan Glover Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: unbind set in rule from commit path

2019-02-04T16:29:17Z

Anonymous sets that are bound to rules from the same transaction trigger a kernel splat from the abort path due to double set list removal and double free. This patch updates the logic to search for the transaction that is responsible for creating the set and disable the set list removal and release, given the rule is now responsible for this. Lookup is reverse since the transaction that adds the set is likely to be at the tail of the list. Moreover, this patch adds the unbind step to deliver the event from the commit path. This should not be done from the worker thread, since we have no guarantees of in-order delivery to the listener. This patch removes the assumption that both activate and deactivate callbacks need to be provided. Fixes: cd5125d8f518 ("netfilter: nf_tables: split set destruction in deactivate and destroy phase") Reported-by: Mikhail Morfikov Signed-off-by: Pablo Neira Ayuso

netfilter: nf_nat: skip nat clash resolution for same-origin entries

2019-02-04T13:26:11Z

It is possible that two concurrent packets originating from the same socket of a connection-less protocol (e.g. UDP) can end up having different IP_CT_DIR_REPLY tuples which results in one of the packets being dropped. To illustrate this, consider the following simplified scenario: 1. Packet A and B are sent at the same time from two different threads by same UDP socket. No matching conntrack entry exists yet. Both packets cause allocation of a new conntrack entry. 2. get_unique_tuple gets called for A. No clashing entry found. conntrack entry for A is added to main conntrack table. 3. get_unique_tuple is called for B and will find that the reply tuple of B is already taken by A. It will allocate a new UDP source port for B to resolve the clash. 4. conntrack entry for B cannot be added to main conntrack table because its ORIGINAL direction is clashing with A and the REPLY directions of A and B are not the same anymore due to UDP source port reallocation done in step 3. This patch modifies nf_conntrack_tuple_taken so it doesn't consider colliding reply tuples if the IP_CT_DIR_ORIGINAL tuples are equal. [ Florian: simplify patch to not use .allow_clash setting and always ignore identical flows ] Signed-off-by: Martynas Pumputis Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: nfnetlink_osf: add missing fmatch check

2019-01-28T10:09:11Z

When we check the tcp options of a packet and it doesn't match the current fingerprint, the tcp packet option pointer must be restored to its initial value in order to do the proper tcp options check for the next fingerprint. Here we can see an example. Assumming the following fingerprint base with two lines: S10:64:1:60:M*,S,T,N,W6: Linux:3.0::Linux 3.0 S20:64:1:60:M*,S,T,N,W7: Linux:4.19:arch:Linux 4.1 Where TCP options are the last field in the OS signature, all of them overlap except by the last one, ie. 'W6' versus 'W7'. In case a packet for Linux 4.19 kicks in, the osf finds no matching because the TCP options pointer is updated after checking for the TCP options in the first line. Therefore, reset pointer back to where it should be. Fixes: 11eeef41d5f6 ("netfilter: passive OS fingerprint xtables match") Signed-off-by: Fernando Fernandez Mancera Signed-off-by: Pablo Neira Ayuso

ipvs: Fix signed integer overflow when setsockopt timeout

2019-01-24T12:38:54Z

There is a UBSAN bug report as below: UBSAN: Undefined behaviour in net/netfilter/ipvs/ip_vs_ctl.c:2227:21 signed integer overflow: -2147483647 * 1000 cannot be represented in type 'int' Reproduce program: #include #include #include #define IPPROTO_IP 0 #define IPPROTO_RAW 255 #define IP_VS_BASE_CTL (64+1024+64) #define IP_VS_SO_SET_TIMEOUT (IP_VS_BASE_CTL+10) /* The argument to IP_VS_SO_GET_TIMEOUT */ struct ipvs_timeout_t { int tcp_timeout; int tcp_fin_timeout; int udp_timeout; }; int main() { int ret = -1; int sockfd = -1; struct ipvs_timeout_t to; sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW); if (sockfd == -1) { printf("socket init error\n"); return -1; } to.tcp_timeout = -2147483647; to.tcp_fin_timeout = -2147483647; to.udp_timeout = -2147483647; ret = setsockopt(sockfd, IPPROTO_IP, IP_VS_SO_SET_TIMEOUT, (char *)(&to), sizeof(to)); printf("setsockopt return %d\n", ret); return ret; } Return -EINVAL if the timeout value is negative or max than 'INT_MAX / HZ'. Signed-off-by: ZhangXiaoxu Acked-by: Simon Horman Signed-off-by: Pablo Neira Ayuso