kernel/linux.git/net/ipv4/ip_sockglue.c, branch linux-4.16.y

ipv4: remove warning in ip_recv_error

2018-06-11T20:48:15+00:00

[ Upstream commit 730c54d59403658a62af6517338fa8d4922c1b28 ] A precondition check in ip_recv_error triggered on an otherwise benign race. Remove the warning. The warning triggers when passing an ipv6 socket to this ipv4 error handling function. RaceFuzzer was able to trigger it due to a race in setsockopt IPV6_ADDRFORM. --- CPU0 do_ipv6_setsockopt sk->sk_socket->ops = &inet_dgram_ops; --- CPU1 sk->sk_prot->recvmsg udp_recvmsg ip_recv_error WARN_ON_ONCE(sk->sk_family == AF_INET6); --- CPU0 do_ipv6_setsockopt sk->sk_family = PF_INET; This socket option converts a v6 socket that is connected to a v4 peer to an v4 socket. It updates the socket on the fly, changing fields in sk as well as other structs. This is inherently non-atomic. It races with the lockless udp_recvmsg path. No other code makes an assumption that these fields are updated atomically. It is benign here, too, as ip_recv_error cares only about the protocol of the skbs enqueued on the error queue, for which sk_family is not a precise predictor (thanks to another isue with IPV6_ADDRFORM). Link: http://lkml.kernel.org/r/20180518120826.GA19515@dragonet.kaist.ac.kr Fixes: 7ce875e5ecb8 ("ipv4: warn once on passing AF_INET6 socket to ip_recv_error") Reported-by: DaeRyong Jeong Suggested-by: Eric Dumazet Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: Only honor ifindex in IP_PKTINFO if non-0

2018-03-06T21:36:44+00:00

Only allow ifindex from IP_PKTINFO to override SO_BINDTODEVICE settings if the index is actually set in the message. Signed-off-by: David Ahern Signed-off-by: David S. Miller

netfilter: drop outermost socket lock in getsockopt()

2018-02-14T19:44:42+00:00

The Syzbot reported a possible deadlock in the netfilter area caused by rtnl lock, xt lock and socket lock being acquired with a different order on different code paths, leading to the following backtrace: Reviewed-by: Xin Long ====================================================== WARNING: possible circular locking dependency detected 4.15.0+ #301 Not tainted ------------------------------------------------------ syzkaller233489/4179 is trying to acquire lock: (rtnl_mutex){+.+.}, at: [<0000000048e996fd>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 but task is already holding lock: (&xt[i].mutex){+.+.}, at: [<00000000328553a2>] xt_find_table_lock+0x3e/0x3e0 net/netfilter/x_tables.c:1041 which lock already depends on the new lock. === Since commit 3f34cfae1230 ("netfilter: on sockopt() acquire sock lock only in the required scope"), we already acquire the socket lock in the innermost scope, where needed. In such commit I forgot to remove the outer-most socket lock from the getsockopt() path, this commit addresses the issues dropping it now. v1 -> v2: fix bad subj, added relavant 'fixes' tag Fixes: 22265a5c3c10 ("netfilter: xt_TEE: resolve oif using netdevice notifiers") Fixes: 202f59afd441 ("netfilter: ipt_CLUSTERIP: do not hold dev") Fixes: 3f34cfae1230 ("netfilter: on sockopt() acquire sock lock only in the required scope") Reported-by: syzbot+ddde1c7b7ff7442d7f2d@syzkaller.appspotmail.com Suggested-by: Florian Westphal Signed-off-by: Paolo Abeni Signed-off-by: Pablo Neira Ayuso

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

2018-02-01T19:41:46+00:00

Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contains Netfilter fixes for your net tree, they are: 1) Fix OOM that syskaller triggers with ipt_replace.size = -1 and IPT_SO_SET_REPLACE socket option, from Dmitry Vyukov. 2) Check for too long extension name in xt_request_find_{match|target} that result in out-of-bound reads, from Eric Dumazet. 3) Fix memory exhaustion bug in ipset hash:*net* types when adding ranges that look like x.x.x.x-255.255.255.255, from Jozsef Kadlecsik. 4) Fix pointer leaks to userspace in x_tables, from Dmitry Vyukov. 5) Insufficient sanity checks in clusterip_tg_check(), also from Dmitry. ==================== Signed-off-by: David S. Miller

netfilter: on sockopt() acquire sock lock only in the required scope

2018-01-31T15:37:47+00:00

Syzbot reported several deadlocks in the netfilter area caused by rtnl lock and socket lock being acquired with a different order on different code paths, leading to backtraces like the following one: ====================================================== WARNING: possible circular locking dependency detected 4.15.0-rc9+ #212 Not tainted ------------------------------------------------------ syzkaller041579/3682 is trying to acquire lock: (sk_lock-AF_INET6){+.+.}, at: [<000000008775e4dd>] lock_sock include/net/sock.h:1463 [inline] (sk_lock-AF_INET6){+.+.}, at: [<000000008775e4dd>] do_ipv6_setsockopt.isra.8+0x3c5/0x39d0 net/ipv6/ipv6_sockglue.c:167 but task is already holding lock: (rtnl_mutex){+.+.}, at: [<000000004342eaa9>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (rtnl_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 register_netdevice_notifier+0xad/0x860 net/core/dev.c:1607 tee_tg_check+0x1a0/0x280 net/netfilter/xt_TEE.c:106 xt_check_target+0x22c/0x7d0 net/netfilter/x_tables.c:845 check_target net/ipv6/netfilter/ip6_tables.c:538 [inline] find_check_entry.isra.7+0x935/0xcf0 net/ipv6/netfilter/ip6_tables.c:580 translate_table+0xf52/0x1690 net/ipv6/netfilter/ip6_tables.c:749 do_replace net/ipv6/netfilter/ip6_tables.c:1165 [inline] do_ip6t_set_ctl+0x370/0x5f0 net/ipv6/netfilter/ip6_tables.c:1691 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115 ipv6_setsockopt+0x115/0x150 net/ipv6/ipv6_sockglue.c:928 udpv6_setsockopt+0x45/0x80 net/ipv6/udp.c:1422 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2978 SYSC_setsockopt net/socket.c:1849 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1828 entry_SYSCALL_64_fastpath+0x29/0xa0 -> #0 (sk_lock-AF_INET6){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914 lock_sock_nested+0xc2/0x110 net/core/sock.c:2780 lock_sock include/net/sock.h:1463 [inline] do_ipv6_setsockopt.isra.8+0x3c5/0x39d0 net/ipv6/ipv6_sockglue.c:167 ipv6_setsockopt+0xd7/0x150 net/ipv6/ipv6_sockglue.c:922 udpv6_setsockopt+0x45/0x80 net/ipv6/udp.c:1422 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2978 SYSC_setsockopt net/socket.c:1849 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1828 entry_SYSCALL_64_fastpath+0x29/0xa0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rtnl_mutex); lock(sk_lock-AF_INET6); lock(rtnl_mutex); lock(sk_lock-AF_INET6); *** DEADLOCK *** 1 lock held by syzkaller041579/3682: #0: (rtnl_mutex){+.+.}, at: [<000000004342eaa9>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 The problem, as Florian noted, is that nf_setsockopt() is always called with the socket held, even if the lock itself is required only for very tight scopes and only for some operation. This patch addresses the issues moving the lock_sock() call only where really needed, namely in ipv*_getorigdst(), so that nf_setsockopt() does not need anymore to acquire both locks. Fixes: 22265a5c3c10 ("netfilter: xt_TEE: resolve oif using netdevice notifiers") Reported-by: syzbot+a4c2dc980ac1af699b36@syzkaller.appspotmail.com Suggested-by: Florian Westphal Signed-off-by: Paolo Abeni Signed-off-by: Pablo Neira Ayuso

net/ipv4: Allow send to local broadcast from a socket bound to a VRF

2018-01-26T02:51:31+00:00

Message sends to the local broadcast address (255.255.255.255) require uc_index or sk_bound_dev_if to be set to an egress device. However, responses or only received if the socket is bound to the device. This is overly constraining for processes running in an L3 domain. This patch allows a socket bound to the VRF device to send to the local broadcast address by using IP_UNICAST_IF to set the egress interface with packet receipt handled by the VRF binding. Similar to IP_MULTICAST_IF, relax the constraint on setting IP_UNICAST_IF if a socket is bound to an L3 master device. In this case allow uc_index to be set to an enslaved if sk_bound_dev_if is an L3 master device and is the master device for the ifindex. In udp and raw sendmsg, allow uc_index to override the oif if uc_index master device is oif (ie., the oif is an L3 master and the index is an L3 slave). Signed-off-by: David Ahern Signed-off-by: David S. Miller

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

net: ipv4: fix l3slave check for index returned in IP_PKTINFO

2017-09-15T21:27:51+00:00

rt_iif is only set to the actual egress device for the output path. The recent change to consider the l3slave flag when returning IP_PKTINFO works for local traffic (the correct device index is returned), but it broke the more typical use case of packets received from a remote host always returning the VRF index rather than the original ingress device. Update the fixup to consider l3slave and rt_iif actually getting set. Fixes: 1dfa76390bf05 ("net: ipv4: add check for l3slave for index returned in IP_PKTINFO") Signed-off-by: David Ahern Signed-off-by: David S. Miller

net: ipv4: add check for l3slave for index returned in IP_PKTINFO

2017-08-14T03:05:13+00:00

Similar to the loopback device, for packets sent through a VRF device the index returned in ipi_ifindex needs to be the saved index in rt_iif. Signed-off-by: David Ahern Signed-off-by: David S. Miller

Revert "ipv4: keep skb->dst around in presence of IP options"

2017-08-07T03:51:12+00:00

ip_options_echo() does not use anymore the skb->dst and don't need to keep the dst around for options's sake only. This reverts commit 34b2cef20f19c87999fff3da4071e66937db9644. Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller