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2020-06-03xfrm: fix a warning in xfrm_policy_insert_listXin Long1-6/+1
commit ed17b8d377eaf6b4a01d46942b4c647378a79bdd upstream. This waring can be triggered simply by: # ip xfrm policy update src 192.168.1.1/24 dst 192.168.1.2/24 dir in \ priority 1 mark 0 mask 0x10 #[1] # ip xfrm policy update src 192.168.1.1/24 dst 192.168.1.2/24 dir in \ priority 2 mark 0 mask 0x1 #[2] # ip xfrm policy update src 192.168.1.1/24 dst 192.168.1.2/24 dir in \ priority 2 mark 0 mask 0x10 #[3] Then dmesg shows: [ ] WARNING: CPU: 1 PID: 7265 at net/xfrm/xfrm_policy.c:1548 [ ] RIP: 0010:xfrm_policy_insert_list+0x2f2/0x1030 [ ] Call Trace: [ ] xfrm_policy_inexact_insert+0x85/0xe50 [ ] xfrm_policy_insert+0x4ba/0x680 [ ] xfrm_add_policy+0x246/0x4d0 [ ] xfrm_user_rcv_msg+0x331/0x5c0 [ ] netlink_rcv_skb+0x121/0x350 [ ] xfrm_netlink_rcv+0x66/0x80 [ ] netlink_unicast+0x439/0x630 [ ] netlink_sendmsg+0x714/0xbf0 [ ] sock_sendmsg+0xe2/0x110 The issue was introduced by Commit 7cb8a93968e3 ("xfrm: Allow inserting policies with matching mark and different priorities"). After that, the policies [1] and [2] would be able to be added with different priorities. However, policy [3] will actually match both [1] and [2]. Policy [1] was matched due to the 1st 'return true' in xfrm_policy_mark_match(), and policy [2] was matched due to the 2nd 'return true' in there. It caused WARN_ON() in xfrm_policy_insert_list(). This patch is to fix it by only (the same value and priority) as the same policy in xfrm_policy_mark_match(). Thanks to Yuehaibing, we could make this fix better. v1->v2: - check policy->mark.v == pol->mark.v only without mask. Fixes: 7cb8a93968e3 ("xfrm: Allow inserting policies with matching mark and different priorities") Reported-by: Xiumei Mu <xmu@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03xfrm: allow to accept packets with ipv6 NEXTHDR_HOP in xfrm_inputXin Long1-1/+1
commit afcaf61be9d1dbdee5ec186d1dcc67b6b692180f upstream. For beet mode, when it's ipv6 inner address with nexthdrs set, the packet format might be: ---------------------------------------------------- | outer | | dest | | | ESP | ESP | | IP hdr | ESP | opts.| TCP | Data | Trailer | ICV | ---------------------------------------------------- The nexthdr from ESP could be NEXTHDR_HOP(0), so it should continue processing the packet when nexthdr returns 0 in xfrm_input(). Otherwise, when ipv6 nexthdr is set, the packet will be dropped. I don't see any error cases that nexthdr may return 0. So fix it by removing the check for nexthdr == 0. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03sctp: Start shutdown on association restart if in SHUTDOWN-SENT state and ↵Jere Leppänen1-4/+5
socket is closed [ Upstream commit d3e8e4c11870413789f029a71e72ae6e971fe678 ] Commit bdf6fa52f01b ("sctp: handle association restarts when the socket is closed.") starts shutdown when an association is restarted, if in SHUTDOWN-PENDING state and the socket is closed. However, the rationale stated in that commit applies also when in SHUTDOWN-SENT state - we don't want to move an association to ESTABLISHED state when the socket has been closed, because that results in an association that is unreachable from user space. The problem scenario: 1. Client crashes and/or restarts. 2. Server (using one-to-one socket) calls close(). SHUTDOWN is lost. 3. Client reconnects using the same addresses and ports. 4. Server's association is restarted. The association and the socket move to ESTABLISHED state, even though the server process has closed its descriptor. Also, after step 4 when the server process exits, some resources are leaked in an attempt to release the underlying inet sock structure in ESTABLISHED state: IPv4: Attempt to release TCP socket in state 1 00000000377288c7 Fix by acting the same way as in SHUTDOWN-PENDING state. That is, if an association is restarted in SHUTDOWN-SENT state and the socket is closed, then start shutdown and don't move the association or the socket to ESTABLISHED state. Fixes: bdf6fa52f01b ("sctp: handle association restarts when the socket is closed.") Signed-off-by: Jere Leppänen <jere.leppanen@nokia.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03net: revert "net: get rid of an signed integer overflow in ip_idents_reserve()"Yuqi Jin1-8/+6
[ Upstream commit a6211caa634da39d861a47437ffcda8b38ef421b ] Commit adb03115f459 ("net: get rid of an signed integer overflow in ip_idents_reserve()") used atomic_cmpxchg to replace "atomic_add_return" inside the function "ip_idents_reserve". The reason was to avoid UBSAN warning. However, this change has caused performance degrade and in GCC-8, fno-strict-overflow is now mapped to -fwrapv -fwrapv-pointer and signed integer overflow is now undefined by default at all optimization levels[1]. Moreover, it was a bug in UBSAN vs -fwrapv /-fno-strict-overflow, so Let's revert it safely. [1] https://gcc.gnu.org/gcc-8/changes.html Suggested-by: Peter Zijlstra <peterz@infradead.org> Suggested-by: Eric Dumazet <edumazet@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Jiri Pirko <jiri@resnulli.us> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Jiong Wang <jiongwang@huawei.com> Signed-off-by: Yuqi Jin <jinyuqi@huawei.com> Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03ax25: fix setsockopt(SO_BINDTODEVICE)Eric Dumazet1-2/+4
[ Upstream commit 687775cec056b38a4c8f3291e0dd7a9145f7b667 ] syzbot was able to trigger this trace [1], probably by using a zero optlen. While we are at it, cap optlen to IFNAMSIZ - 1 instead of IFNAMSIZ. [1] BUG: KMSAN: uninit-value in strnlen+0xf9/0x170 lib/string.c:569 CPU: 0 PID: 8807 Comm: syz-executor483 Not tainted 5.7.0-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+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 strnlen+0xf9/0x170 lib/string.c:569 dev_name_hash net/core/dev.c:207 [inline] netdev_name_node_lookup net/core/dev.c:277 [inline] __dev_get_by_name+0x75/0x2b0 net/core/dev.c:778 ax25_setsockopt+0xfa3/0x1170 net/ax25/af_ax25.c:654 __compat_sys_setsockopt+0x4ed/0x910 net/compat.c:403 __do_compat_sys_setsockopt net/compat.c:413 [inline] __se_compat_sys_setsockopt+0xdd/0x100 net/compat.c:410 __ia32_compat_sys_setsockopt+0x62/0x80 net/compat.c:410 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline] do_fast_syscall_32+0x3bf/0x6d0 arch/x86/entry/common.c:398 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f57dd9 Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000ffae8c1c EFLAGS: 00000217 ORIG_RAX: 000000000000016e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000101 RDX: 0000000000000019 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Local variable ----devname@ax25_setsockopt created at: ax25_setsockopt+0xe6/0x1170 net/ax25/af_ax25.c:536 ax25_setsockopt+0xe6/0x1170 net/ax25/af_ax25.c:536 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: device MTU setup, tunnel socket needs a lockR. Parameswaran2-1/+3
commit 57240d007816486131bee88cd474c2a71f0fe224 upstream. The MTU overhead calculation in L2TP device set-up merged via commit b784e7ebfce8cfb16c6f95e14e8532d0768ab7ff needs to be adjusted to lock the tunnel socket while referencing the sub-data structures to derive the socket's IP overhead. Reported-by: Guillaume Nault <g.nault@alphalink.fr> Tested-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: R. Parameswaran <rparames@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: initialise PPP sessions before registering themGuillaume Nault1-31/+38
commit f98be6c6359e7e4a61aaefb9964c1db31cb9ec0c upstream. pppol2tp_connect() initialises L2TP sessions after they've been exposed to the rest of the system by l2tp_session_register(). This puts sessions into transient states that are the source of several races, in particular with session's deletion path. This patch centralises the initialisation code into pppol2tp_session_init(), which is called before the registration phase. The only field that can't be set before session registration is the pppol2tp socket pointer, which has already been converted to RCU. So pppol2tp_connect() should now be race-free. The session's .session_close() callback is now set before registration. Therefore, it's always called when l2tp_core deletes the session, even if it was created by pppol2tp_session_create() and hasn't been plugged to a pppol2tp socket yet. That'd prevent session free because the extra reference taken by pppol2tp_session_close() wouldn't be dropped by the socket's ->sk_destruct() callback (pppol2tp_session_destruct()). We could set .session_close() only while connecting a session to its pppol2tp socket, or teach pppol2tp_session_close() to avoid grabbing a reference when the session isn't connected, but that'd require adding some form of synchronisation to be race free. Instead of that, we can just let the pppol2tp socket hold a reference on the session as soon as it starts depending on it (that is, in pppol2tp_connect()). Then we don't need to utilise pppol2tp_session_close() to hold a reference at the last moment to prevent l2tp_core from dropping it. When releasing the socket, pppol2tp_release() now deletes the session using the standard l2tp_session_delete() function, instead of merely removing it from hash tables. l2tp_session_delete() drops the reference the sessions holds on itself, but also makes sure it doesn't remove a session twice. So it can safely be called, even if l2tp_core already tried, or is concurrently trying, to remove the session. Finally, pppol2tp_session_destruct() drops the reference held by the socket. Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: protect sock pointer of struct pppol2tp_session with RCUGuillaume Nault1-53/+101
commit ee40fb2e1eb5bc0ddd3f2f83c6e39a454ef5a741 upstream. pppol2tp_session_create() registers sessions that can't have their corresponding socket initialised. This socket has to be created by userspace, then connected to the session by pppol2tp_connect(). Therefore, we need to protect the pppol2tp socket pointer of L2TP sessions, so that it can safely be updated when userspace is connecting or closing the socket. This will eventually allow pppol2tp_connect() to avoid generating transient states while initialising its parts of the session. To this end, this patch protects the pppol2tp socket pointer using RCU. The pppol2tp socket pointer is still set in pppol2tp_connect(), but only once we know the function isn't going to fail. It's eventually reset by pppol2tp_release(), which now has to wait for a grace period to elapse before it can drop the last reference on the socket. This ensures that pppol2tp_session_get_sock() can safely grab a reference on the socket, even after ps->sk is reset to NULL but before this operation actually gets visible from pppol2tp_session_get_sock(). The rest is standard RCU conversion: pppol2tp_recv(), which already runs in atomic context, is simply enclosed by rcu_read_lock() and rcu_read_unlock(), while other functions are converted to use pppol2tp_session_get_sock() followed by sock_put(). pppol2tp_session_setsockopt() is a special case. It used to retrieve the pppol2tp socket from the L2TP session, which itself was retrieved from the pppol2tp socket. Therefore we can just avoid dereferencing ps->sk and directly use the original socket pointer instead. With all users of ps->sk now handling NULL and concurrent updates, the L2TP ->ref() and ->deref() callbacks aren't needed anymore. Therefore, rather than converting pppol2tp_session_sock_hold() and pppol2tp_session_sock_put(), we can just drop them. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: initialise l2tp_eth sessions before registering themGuillaume Nault1-32/+76
commit ee28de6bbd78c2e18111a0aef43ea746f28d2073 upstream. Sessions must be initialised before being made externally visible by l2tp_session_register(). Otherwise the session may be concurrently deleted before being initialised, which can confuse the deletion path and eventually lead to kernel oops. Therefore, we need to move l2tp_session_register() down in l2tp_eth_create(), but also handle the intermediate step where only the session or the netdevice has been registered. We can't just call l2tp_session_register() in ->ndo_init() because we'd have no way to properly undo this operation in ->ndo_uninit(). Instead, let's register the session and the netdevice in two different steps and protect the session's device pointer with RCU. And now that we allow the session's .dev field to be NULL, we don't need to prevent the netdevice from being removed anymore. So we can drop the dev_hold() and dev_put() calls in l2tp_eth_create() and l2tp_eth_dev_uninit(). Backporting Notes l2tp_eth.c: In l2tp_eth_create the "out" label was renamed to "err". There was one extra occurrence of "goto out" to update. Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: don't register sessions in l2tp_session_create()Guillaume Nault4-20/+36
commit 3953ae7b218df4d1e544b98a393666f9ae58a78c upstream. Sessions created by l2tp_session_create() aren't fully initialised: some pseudo-wire specific operations need to be done before making the session usable. Therefore the PPP and Ethernet pseudo-wires continue working on the returned l2tp session while it's already been exposed to the rest of the system. This can lead to various issues. In particular, the session may enter the deletion process before having been fully initialised, which will confuse the session removal code. This patch moves session registration out of l2tp_session_create(), so that callers can control when the session is exposed to the rest of the system. This is done by the new l2tp_session_register() function. Only pppol2tp_session_create() can be easily converted to avoid modifying its session after registration (the debug message is dropped in order to avoid the need for holding a reference on the session). For pppol2tp_connect() and l2tp_eth_create()), more work is needed. That'll be done in followup patches. For now, let's just register the session right after its creation, like it was done before. The only difference is that we can easily take a reference on the session before registering it, so, at least, we're sure it's not going to be freed while we're working on it. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: fix l2tp_eth module loadingGuillaume Nault1-49/+2
commit 9f775ead5e570e7e19015b9e4e2f3dd6e71a5935 upstream. The l2tp_eth module crashes if its netlink callbacks are run when the pernet data aren't initialised. We should normally register_pernet_device() before the genl callbacks. However, the pernet data only maintain a list of l2tpeth interfaces, and this list is never used. So let's just drop pernet handling instead. Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: pass tunnel pointer to ->session_create()Guillaume Nault4-25/+17
commit f026bc29a8e093edfbb2a77700454b285c97e8ad upstream. Using l2tp_tunnel_find() in pppol2tp_session_create() and l2tp_eth_create() is racy, because no reference is held on the returned session. These functions are only used to implement the ->session_create callback which is run by l2tp_nl_cmd_session_create(). Therefore searching for the parent tunnel isn't necessary because l2tp_nl_cmd_session_create() already has a pointer to it and holds a reference. This patch modifies ->session_create()'s prototype to directly pass the the parent tunnel as parameter, thus avoiding searching for it in pppol2tp_session_create() and l2tp_eth_create(). Since we have to touch the ->session_create() call in l2tp_nl_cmd_session_create(), let's also remove the useless conditional: we know that ->session_create isn't NULL at this point because it's already been checked earlier in this same function. Finally, one might be tempted to think that the removed l2tp_tunnel_find() calls were harmless because they would return the same tunnel as the one held by l2tp_nl_cmd_session_create() anyway. But that tunnel might be removed and a new one created with same tunnel Id before the l2tp_tunnel_find() call. In this case l2tp_tunnel_find() would return the new tunnel which wouldn't be protected by the reference held by l2tp_nl_cmd_session_create(). Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: prevent creation of sessions on terminated tunnelsGuillaume Nault2-13/+32
commit f3c66d4e144a0904ea9b95d23ed9f8eb38c11bfb upstream. l2tp_tunnel_destruct() sets tunnel->sock to NULL, then removes the tunnel from the pernet list and finally closes all its sessions. Therefore, it's possible to add a session to a tunnel that is still reachable, but for which tunnel->sock has already been reset. This can make l2tp_session_create() dereference a NULL pointer when calling sock_hold(tunnel->sock). This patch adds the .acpt_newsess field to struct l2tp_tunnel, which is used by l2tp_tunnel_closeall() to prevent addition of new sessions to tunnels. Resetting tunnel->sock is done after l2tp_tunnel_closeall() returned, so that l2tp_session_add_to_tunnel() can safely take a reference on it when .acpt_newsess is true. The .acpt_newsess field is modified in l2tp_tunnel_closeall(), rather than in l2tp_tunnel_destruct(), so that it benefits all tunnel removal mechanisms. E.g. on UDP tunnels, a session could be added to a tunnel after l2tp_udp_encap_destroy() proceeded. This would prevent the tunnel from being removed because of the references held by this new session on the tunnel and its socket. Even though the session could be removed manually later on, this defeats the purpose of commit 9980d001cec8 ("l2tp: add udp encap socket destroy handler"). Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: hold tunnel used while creating sessions with netlinkGuillaume Nault1-9/+12
commit e702c1204eb57788ef189c839c8c779368267d70 upstream. Use l2tp_tunnel_get() to retrieve tunnel, so that it can't go away on us. Otherwise l2tp_tunnel_destruct() might release the last reference count concurrently, thus freeing the tunnel while we're using it. Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: hold tunnel while handling genl TUNNEL_GET commandsGuillaume Nault1-12/+15
commit 4e4b21da3acc68a7ea55f850cacc13706b7480e9 upstream. Use l2tp_tunnel_get() instead of l2tp_tunnel_find() so that we get a reference on the tunnel, preventing l2tp_tunnel_destruct() from freeing it from under us. Also move l2tp_tunnel_get() below nlmsg_new() so that we only take the reference when needed. Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: hold tunnel while handling genl tunnel updatesGuillaume Nault1-2/+4
commit 8c0e421525c9eb50d68e8f633f703ca31680b746 upstream. We need to make sure the tunnel is not going to be destroyed by l2tp_tunnel_destruct() concurrently. Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: hold tunnel while processing genl delete commandGuillaume Nault1-2/+4
commit bb0a32ce4389e17e47e198d2cddaf141561581ad upstream. l2tp_nl_cmd_tunnel_delete() needs to take a reference on the tunnel, to prevent it from being concurrently freed by l2tp_tunnel_destruct(). Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: hold tunnel while looking up sessions in l2tp_netlinkGuillaume Nault3-47/+38
commit 54652eb12c1b72e9602d09cb2821d5760939190f upstream. l2tp_tunnel_find() doesn't take a reference on the returned tunnel. Therefore, it's unsafe to use it because the returned tunnel can go away on us anytime. Fix this by defining l2tp_tunnel_get(), which works like l2tp_tunnel_find(), but takes a reference on the returned tunnel. Caller then has to drop this reference using l2tp_tunnel_dec_refcount(). As l2tp_tunnel_dec_refcount() needs to be moved to l2tp_core.h, let's simplify the patch and not move the L2TP_REFCNT_DEBUG part. This code has been broken (not even compiling) in May 2012 by commit a4ca44fa578c ("net: l2tp: Standardize logging styles") and fixed more than two years later by commit 29abe2fda54f ("l2tp: fix missing line continuation"). So it doesn't appear to be used by anyone. Same thing for l2tp_tunnel_free(); instead of moving it to l2tp_core.h, let's just simplify things and call kfree_rcu() directly in l2tp_tunnel_dec_refcount(). Extra assertions and debugging code provided by l2tp_tunnel_free() didn't help catching any of the reference counting and socket handling issues found while working on this series. Backporting Notes l2tp_core.c: This patch deletes some code / moves some code to l2tp_core.h and follows the patch (not including in this series) that switched from atomic to refcount_t. Moved code changed back to atomic. Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: initialise session's refcount before making it reachableGuillaume Nault1-4/+2
commit 9ee369a405c57613d7c83a3967780c3e30c52ecc upstream. Sessions must be fully initialised before calling l2tp_session_add_to_tunnel(). Otherwise, there's a short time frame where partially initialised sessions can be accessed by external users. Backporting Notes l2tp_core.c: moving code that had been converted from atomic to refcount_t by an earlier change (which isn't being included in this patch series). Fixes: dbdbc73b4478 ("l2tp: fix duplicate session creation") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: define parameters of l2tp_tunnel_find*() as "const"Guillaume Nault2-4/+4
commit 2f858b928bf5a8174911aaec76b8b72a9ca0533d upstream. l2tp_tunnel_find() and l2tp_tunnel_find_nth() don't modify "net". Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: define parameters of l2tp_session_get*() as "const"Guillaume Nault2-5/+7
commit 9aaef50c44f132e040dcd7686c8e78a3390037c5 upstream. Make l2tp_pernet()'s parameter constant, so that l2tp_session_get*() can declare their "net" variable as "const". Also constify "ifname" in l2tp_session_get_by_ifname(). Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: remove l2tp_session_find()Guillaume Nault2-53/+1
commit 55a3ce3b9d98f752df9e2cfb1cba7e715522428a upstream. This function isn't used anymore. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: remove useless duplicate session detection in l2tp_netlinkGuillaume Nault1-5/+0
commit af87ae465abdc070de0dc35d6c6a9e7a8cd82987 upstream. There's no point in checking for duplicate sessions at the beginning of l2tp_nl_cmd_session_create(); the ->session_create() callbacks already return -EEXIST when the session already exists. Furthermore, even if l2tp_session_find() returns NULL, a new session might be created right after the test. So relying on ->session_create() to avoid duplicate session is the only sane behaviour. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27L2TP:Adjust intf MTU, add underlay L3, L2 hdrs.R. Parameswaran1-4/+51
commit b784e7ebfce8cfb16c6f95e14e8532d0768ab7ff upstream. Existing L2TP kernel code does not derive the optimal MTU for Ethernet pseudowires and instead leaves this to a userspace L2TP daemon or operator. If an MTU is not specified, the existing kernel code chooses an MTU that does not take account of all tunnel header overheads, which can lead to unwanted IP fragmentation. When L2TP is used without a control plane (userspace daemon), we would prefer that the kernel does a better job of choosing a default pseudowire MTU, taking account of all tunnel header overheads, including IP header options, if any. This patch addresses this. Change-set here uses the new kernel function, kernel_sock_ip_overhead(), to factor the outer IP overhead on the L2TP tunnel socket (including IP Options, if any) when calculating the default MTU for an Ethernet pseudowire, along with consideration of the inner Ethernet header. Signed-off-by: R. Parameswaran <rparames@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27New kernel function to get IP overhead on a socket.R. Parameswaran1-0/+46
commit 113c3075931a334f899008f6c753abe70a3a9323 upstream. A new function, kernel_sock_ip_overhead(), is provided to calculate the cumulative overhead imposed by the IP Header and IP options, if any, on a socket's payload. The new function returns an overhead of zero for sockets that do not belong to the IPv4 or IPv6 address families. This is used in the L2TP code path to compute the total outer IP overhead on the L2TP tunnel socket when calculating the default MTU for Ethernet pseudowires. Signed-off-by: R. Parameswaran <rparames@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27net: l2tp: ppp: change PPPOL2TP_MSG_* => L2TP_MSG_*Asbjørn Sloth Tønnesen1-27/+27
commit fba40c632c6473fa89660e870a6042c0fe733f8c upstream. Signed-off-by: Asbjoern Sloth Toennesen <asbjorn@asbjorn.st> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27net: l2tp: export debug flags to UAPIAsbjørn Sloth Tønnesen1-10/+0
commit 41c43fbee68f4f9a2a9675d83bca91c77862d7f0 upstream. Move the L2TP_MSG_* definitions to UAPI, as it is part of the netlink API. Signed-off-by: Asbjoern Sloth Toennesen <asbjorn@asbjorn.st> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: don't use l2tp_tunnel_find() in l2tp_ip and l2tp_ip6Guillaume Nault2-29/+16
commit 8f7dc9ae4a7aece9fbc3e6637bdfa38b36bcdf09 upstream. Using l2tp_tunnel_find() in l2tp_ip_recv() is wrong for two reasons: * It doesn't take a reference on the returned tunnel, which makes the call racy wrt. concurrent tunnel deletion. * The lookup is only based on the tunnel identifier, so it can return a tunnel that doesn't match the packet's addresses or protocol. For example, a packet sent to an L2TPv3 over IPv6 tunnel can be delivered to an L2TPv2 over UDPv4 tunnel. This is worse than a simple cross-talk: when delivering the packet to an L2TP over UDP tunnel, the corresponding socket is UDP, where ->sk_backlog_rcv() is NULL. Calling sk_receive_skb() will then crash the kernel by trying to execute this callback. And l2tp_tunnel_find() isn't even needed here. __l2tp_ip_bind_lookup() properly checks the socket binding and connection settings. It was used as a fallback mechanism for finding tunnels that didn't have their data path registered yet. But it's not limited to this case and can be used to replace l2tp_tunnel_find() in the general case. Fix l2tp_ip6 in the same way. Fixes: 0d76751fad77 ("l2tp: Add L2TPv3 IP encapsulation (no UDP) support") Fixes: a32e0eec7042 ("l2tp: introduce L2TPv3 IP encapsulation support for IPv6") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Nicolas Schier <n.schier@avm.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: take a reference on sessions used in genetlink handlersGuillaume Nault3-16/+35
commit 2777e2ab5a9cf2b4524486c6db1517a6ded25261 upstream. Callers of l2tp_nl_session_find() need to hold a reference on the returned session since there's no guarantee that it isn't going to disappear from under them. Relying on the fact that no l2tp netlink message may be processed concurrently isn't enough: sessions can be deleted by other means (e.g. by closing the PPPOL2TP socket of a ppp pseudowire). l2tp_nl_cmd_session_delete() is a bit special: it runs a callback function that may require a previous call to session->ref(). In particular, for ppp pseudowires, the callback is l2tp_session_delete(), which then calls pppol2tp_session_close() and dereferences the PPPOL2TP socket. The socket might already be gone at the moment l2tp_session_delete() calls session->ref(), so we need to take a reference during the session lookup. So we need to pass the do_ref variable down to l2tp_session_get() and l2tp_session_get_by_ifname(). Since all callers have to be updated, l2tp_session_find_by_ifname() and l2tp_nl_session_find() are renamed to reflect their new behaviour. Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: hold session while sending creation notificationsGuillaume Nault1-2/+4
commit 5e6a9e5a3554a5b3db09cdc22253af1849c65dff upstream. l2tp_session_find() doesn't take any reference on the returned session. Therefore, the session may disappear while sending the notification. Use l2tp_session_get() instead and decrement session's refcount once the notification is sent. Backporting Notes This is a backport of a backport. Fixes: 33f72e6f0c67 ("l2tp : multicast notification to the registered listeners") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: fix racy socket lookup in l2tp_ip and l2tp_ip6 bind()Guillaume Nault2-38/+32
commit d5e3a190937a1e386671266202c62565741f0f1a upstream. It's not enough to check for sockets bound to same address at the beginning of l2tp_ip{,6}_bind(): even if no socket is found at that time, a socket with the same address could be bound before we take the l2tp lock again. This patch moves the lookup right before inserting the new socket, so that no change can ever happen to the list between address lookup and socket insertion. Care is taken to avoid side effects on the socket in case of failure. That is, modifications of the socket are done after the lookup, when binding is guaranteed to succeed, and before releasing the l2tp lock, so that concurrent lookups will always see fully initialised sockets. For l2tp_ip, 'ret' is set to -EINVAL before checking the SOCK_ZAPPED bit. Error code was mistakenly set to -EADDRINUSE on error by commit 32c231164b76 ("l2tp: fix racy SOCK_ZAPPED flag check in l2tp_ip{,6}_bind()"). Using -EINVAL restores original behaviour. For l2tp_ip6, the lookup is now always done with the correct bound device. Before this patch, when binding to a link-local address, the lookup was done with the original sk->sk_bound_dev_if, which was later overwritten with addr->l2tp_scope_id. Lookup is now performed with the final sk->sk_bound_dev_if value. Finally, the (addr_len >= sizeof(struct sockaddr_in6)) check has been dropped: addr is a sockaddr_l2tpip6 not sockaddr_in6 and addr_len has already been checked at this point (this part of the code seems to have been copy-pasted from net/ipv6/raw.c). Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: lock socket before checking flags in connect()Guillaume Nault3-13/+26
commit 0382a25af3c771a8e4d5e417d1834cbe28c2aaac upstream. Socket flags aren't updated atomically, so the socket must be locked while reading the SOCK_ZAPPED flag. This issue exists for both l2tp_ip and l2tp_ip6. For IPv6, this patch also brings error handling for __ip6_datagram_connect() failures. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20netlabel: cope with NULL catmapPaolo Abeni2-2/+10
[ Upstream commit eead1c2ea2509fd754c6da893a94f0e69e83ebe4 ] The cipso and calipso code can set the MLS_CAT attribute on successful parsing, even if the corresponding catmap has not been allocated, as per current configuration and external input. Later, selinux code tries to access the catmap if the MLS_CAT flag is present via netlbl_catmap_getlong(). That may cause null ptr dereference while processing incoming network traffic. Address the issue setting the MLS_CAT flag only if the catmap is really allocated. Additionally let netlbl_catmap_getlong() cope with NULL catmap. Reported-by: Matthew Sheets <matthew.sheets@gd-ms.com> Fixes: 4b8feff251da ("netlabel: fix the horribly broken catmap functions") Fixes: ceba1832b1b2 ("calipso: Set the calipso socket label to match the secattr.") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20net: ipv4: really enforce backoff for redirectsPaolo Abeni1-1/+1
[ Upstream commit 57644431a6c2faac5d754ebd35780cf43a531b1a ] In commit b406472b5ad7 ("net: ipv4: avoid mixed n_redirects and rate_tokens usage") I missed the fact that a 0 'rate_tokens' will bypass the backoff algorithm. Since rate_tokens is cleared after a redirect silence, and never incremented on redirects, if the host keeps receiving packets requiring redirect it will reply ignoring the backoff. Additionally, the 'rate_last' field will be updated with the cadence of the ingress packet requiring redirect. If that rate is high enough, that will prevent the host from generating any other kind of ICMP messages The check for a zero 'rate_tokens' value was likely a shortcut to avoid the more complex backoff algorithm after a redirect silence period. Address the issue checking for 'n_redirects' instead, which is incremented on successful redirect, and does not interfere with other ICMP replies. Fixes: b406472b5ad7 ("net: ipv4: avoid mixed n_redirects and rate_tokens usage") Reported-and-tested-by: Colin Walters <walters@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20net: fix a potential recursive NETDEV_FEAT_CHANGECong Wang1-1/+3
[ Upstream commit dd912306ff008891c82cd9f63e8181e47a9cb2fb ] syzbot managed to trigger a recursive NETDEV_FEAT_CHANGE event between bonding master and slave. I managed to find a reproducer for this: ip li set bond0 up ifenslave bond0 eth0 brctl addbr br0 ethtool -K eth0 lro off brctl addif br0 bond0 ip li set br0 up When a NETDEV_FEAT_CHANGE event is triggered on a bonding slave, it captures this and calls bond_compute_features() to fixup its master's and other slaves' features. However, when syncing with its lower devices by netdev_sync_lower_features() this event is triggered again on slaves when the LRO feature fails to change, so it goes back and forth recursively until the kernel stack is exhausted. Commit 17b85d29e82c intentionally lets __netdev_update_features() return -1 for such a failure case, so we have to just rely on the existing check inside netdev_sync_lower_features() and skip NETDEV_FEAT_CHANGE event only for this specific failure case. Fixes: fd867d51f889 ("net/core: generic support for disabling netdev features down stack") Reported-by: syzbot+e73ceacfd8560cc8a3ca@syzkaller.appspotmail.com Reported-by: syzbot+c2fb6f9ddcea95ba49b5@syzkaller.appspotmail.com Cc: Jarod Wilson <jarod@redhat.com> Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jann Horn <jannh@google.com> Reviewed-by: Jay Vosburgh <jay.vosburgh@canonical.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20netfilter: conntrack: avoid gcc-10 zero-length-bounds warningArnd Bergmann1-2/+2
[ Upstream commit 2c407aca64977ede9b9f35158e919773cae2082f ] gcc-10 warns around a suspicious access to an empty struct member: net/netfilter/nf_conntrack_core.c: In function '__nf_conntrack_alloc': net/netfilter/nf_conntrack_core.c:1522:9: warning: array subscript 0 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[0]'} [-Wzero-length-bounds] 1522 | memset(&ct->__nfct_init_offset[0], 0, | ^~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from net/netfilter/nf_conntrack_core.c:37: include/net/netfilter/nf_conntrack.h:90:5: note: while referencing '__nfct_init_offset' 90 | u8 __nfct_init_offset[0]; | ^~~~~~~~~~~~~~~~~~ The code is correct but a bit unusual. Rework it slightly in a way that does not trigger the warning, using an empty struct instead of an empty array. There are probably more elegant ways to do this, but this is the smallest change. Fixes: c41884ce0562 ("netfilter: conntrack: avoid zeroing timer") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-20gre: do not keep the GRE header around in collect medata modeJiri Benc1-1/+6
[ Upstream commit e271c7b4420ddbb9fae82a2b31a5ab3edafcf4fe ] For ipgre interface in collect metadata mode, it doesn't make sense for the interface to be of ARPHRD_IPGRE type. The outer header of received packets is not needed, as all the information from it is present in metadata_dst. We already don't set ipgre_header_ops for collect metadata interfaces, which is the only consumer of mac_header pointing to the outer IP header. Just set the interface type to ARPHRD_NONE in collect metadata mode for ipgre (not gretap, that still correctly stays ARPHRD_ETHER) and reset mac_header. Fixes: a64b04d86d14 ("gre: do not assign header_ops in collect metadata mode") Fixes: 2e15ea390e6f4 ("ip_gre: Add support to collect tunnel metadata.") Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-20net: openvswitch: fix csum updates for MPLS actionsJohn Hurley1-4/+2
[ Upstream commit 0e3183cd2a64843a95b62f8bd4a83605a4cf0615 ] Skbs may have their checksum value populated by HW. If this is a checksum calculated over the entire packet then the CHECKSUM_COMPLETE field is marked. Changes to the data pointer on the skb throughout the network stack still try to maintain this complete csum value if it is required through functions such as skb_postpush_rcsum. The MPLS actions in Open vSwitch modify a CHECKSUM_COMPLETE value when changes are made to packet data without a push or a pull. This occurs when the ethertype of the MAC header is changed or when MPLS lse fields are modified. The modification is carried out using the csum_partial function to get the csum of a buffer and add it into the larger checksum. The buffer is an inversion of the data to be removed followed by the new data. Because the csum is calculated over 16 bits and these values align with 16 bits, the effect is the removal of the old value from the CHECKSUM_COMPLETE and addition of the new value. However, the csum fed into the function and the outcome of the calculation are also inverted. This would only make sense if it was the new value rather than the old that was inverted in the input buffer. Fix the issue by removing the bit inverts in the csum_partial calculation. The bug was verified and the fix tested by comparing the folded value of the updated CHECKSUM_COMPLETE value with the folded value of a full software checksum calculation (reset skb->csum to 0 and run skb_checksum_complete(skb)). Prior to the fix the outcomes differed but after they produce the same result. Fixes: 25cd9ba0abc0 ("openvswitch: Add basic MPLS support to kernel") Fixes: bc7cc5999fd3 ("openvswitch: update checksum in {push,pop}_mpls") Signed-off-by: John Hurley <john.hurley@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Acked-by: Pravin B Shelar <pshelar@ovn.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-20drop_monitor: work around gcc-10 stringop-overflow warningArnd Bergmann1-4/+7
[ Upstream commit dc30b4059f6e2abf3712ab537c8718562b21c45d ] The current gcc-10 snapshot produces a false-positive warning: net/core/drop_monitor.c: In function 'trace_drop_common.constprop': cc1: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=] In file included from net/core/drop_monitor.c:23: include/uapi/linux/net_dropmon.h:36:8: note: at offset 0 to object 'entries' with size 4 declared here 36 | __u32 entries; | ^~~~~~~ I reported this in the gcc bugzilla, but in case it does not get fixed in the release, work around it by using a temporary variable. Fixes: 9a8afc8d3962 ("Network Drop Monitor: Adding drop monitor implementation & Netlink protocol") Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94881 Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-20net: handle no dst on skb in icmp6_sendDavid Ahern1-2/+4
commit 79dc7e3f1cd323be4c81aa1a94faa1b3ed987fb2 upstream. Andrey reported the following while fuzzing the kernel with syzkaller: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Modules linked in: CPU: 0 PID: 3859 Comm: a.out Not tainted 4.9.0-rc6+ #429 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff8800666d4200 task.stack: ffff880067348000 RIP: 0010:[<ffffffff833617ec>] [<ffffffff833617ec>] icmp6_send+0x5fc/0x1e30 net/ipv6/icmp.c:451 RSP: 0018:ffff88006734f2c0 EFLAGS: 00010206 RAX: ffff8800666d4200 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000018 RBP: ffff88006734f630 R08: ffff880064138418 R09: 0000000000000003 R10: dffffc0000000000 R11: 0000000000000005 R12: 0000000000000000 R13: ffffffff84e7e200 R14: ffff880064138484 R15: ffff8800641383c0 FS: 00007fb3887a07c0(0000) GS:ffff88006cc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000000 CR3: 000000006b040000 CR4: 00000000000006f0 Stack: ffff8800666d4200 ffff8800666d49f8 ffff8800666d4200 ffffffff84c02460 ffff8800666d4a1a 1ffff1000ccdaa2f ffff88006734f498 0000000000000046 ffff88006734f440 ffffffff832f4269 ffff880064ba7456 0000000000000000 Call Trace: [<ffffffff83364ddc>] icmpv6_param_prob+0x2c/0x40 net/ipv6/icmp.c:557 [< inline >] ip6_tlvopt_unknown net/ipv6/exthdrs.c:88 [<ffffffff83394405>] ip6_parse_tlv+0x555/0x670 net/ipv6/exthdrs.c:157 [<ffffffff8339a759>] ipv6_parse_hopopts+0x199/0x460 net/ipv6/exthdrs.c:663 [<ffffffff832ee773>] ipv6_rcv+0xfa3/0x1dc0 net/ipv6/ip6_input.c:191 ... icmp6_send / icmpv6_send is invoked for both rx and tx paths. In both cases the dst->dev should be preferred for determining the L3 domain if the dst has been set on the skb. Fallback to the skb->dev if it has not. This covers the case reported here where icmp6_send is invoked on Rx before the route lookup. Fixes: 5d41ce29e ("net: icmp6_send should use dst dev to determine L3 domain") Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Nobuhiro Iwamatsu (CIP) <nobuhiro1.iwamatsu@toshiba.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20net: ipv6_stub: use ip6_dst_lookup_flow instead of ip6_dst_lookupSabrina Dubroca4-13/+16
commit 6c8991f41546c3c472503dff1ea9daaddf9331c2 upstream. ipv6_stub uses the ip6_dst_lookup function to allow other modules to perform IPv6 lookups. However, this function skips the XFRM layer entirely. All users of ipv6_stub->ip6_dst_lookup use ip_route_output_flow (via the ip_route_output_key and ip_route_output helpers) for their IPv4 lookups, which calls xfrm_lookup_route(). This patch fixes this inconsistent behavior by switching the stub to ip6_dst_lookup_flow, which also calls xfrm_lookup_route(). This requires some changes in all the callers, as these two functions take different arguments and have different return types. Fixes: 5f81bd2e5d80 ("ipv6: export a stub for IPv6 symbols used by vxlan") Reported-by: Xiumei Mu <xmu@redhat.com> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 4.4: - Drop changes in lwt_bpf.c, mlx5, and rxe - Adjust filename, context, indentation] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20net: ipv6: add net argument to ip6_dst_lookup_flowSabrina Dubroca10-18/+18
commit c4e85f73afb6384123e5ef1bba3315b2e3ad031e upstream. This will be used in the conversion of ipv6_stub to ip6_dst_lookup_flow, as some modules currently pass a net argument without a socket to ip6_dst_lookup. This is equivalent to commit 343d60aada5a ("ipv6: change ipv6_stub_impl.ipv6_dst_lookup to take net argument"). Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 4.4: adjust context] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20batman-adv: fix batadv_nc_random_weight_tqGeorge Spelvin1-8/+1
commit fd0c42c4dea54335967c5a86f15fc064235a2797 upstream. and change to pseudorandom numbers, as this is a traffic dithering operation that doesn't need crypto-grade. The previous code operated in 4 steps: 1. Generate a random byte 0 <= rand_tq <= 255 2. Multiply it by BATADV_TQ_MAX_VALUE - tq 3. Divide by 255 (= BATADV_TQ_MAX_VALUE) 4. Return BATADV_TQ_MAX_VALUE - rand_tq This would apperar to scale (BATADV_TQ_MAX_VALUE - tq) by a random value between 0/255 and 255/255. But! The intermediate value between steps 3 and 4 is stored in a u8 variable. So it's truncated, and most of the time, is less than 255, after which the division produces 0. Specifically, if tq is odd, the product is always even, and can never be 255. If tq is even, there's exactly one random byte value that will produce a product byte of 255. Thus, the return value is 255 (511/512 of the time) or 254 (1/512 of the time). If we assume that the truncation is a bug, and the code is meant to scale the input, a simpler way of looking at it is that it's returning a random value between tq and BATADV_TQ_MAX_VALUE, inclusive. Well, we have an optimized function for doing just that. Fixes: 3c12de9a5c75 ("batman-adv: network coding - code and transmit packets if possible") Signed-off-by: George Spelvin <lkml@sdf.org> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20ipv6: fix cleanup ordering for ip6_mr failureSabrina Dubroca1-3/+3
commit afe49de44c27a89e8e9631c44b5ffadf6ace65e2 upstream. Commit 15e668070a64 ("ipv6: reorder icmpv6_init() and ip6_mr_init()") moved the cleanup label for ipmr_fail, but should have changed the contents of the cleanup labels as well. Now we can end up cleaning up icmpv6 even though it hasn't been initialized (jump to icmp_fail or ipmr_fail). Simply undo things in the reverse order of their initialization. Example of panic (triggered by faking a failure of icmpv6_init): kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN PTI [...] RIP: 0010:__list_del_entry_valid+0x79/0x160 [...] Call Trace: ? lock_release+0x8a0/0x8a0 unregister_pernet_operations+0xd4/0x560 ? ops_free_list+0x480/0x480 ? down_write+0x91/0x130 ? unregister_pernet_subsys+0x15/0x30 ? down_read+0x1b0/0x1b0 ? up_read+0x110/0x110 ? kmem_cache_create_usercopy+0x1b4/0x240 unregister_pernet_subsys+0x1d/0x30 icmpv6_cleanup+0x1d/0x30 inet6_init+0x1b5/0x23f Fixes: 15e668070a64 ("ipv6: reorder icmpv6_init() and ip6_mr_init()") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20sch_choke: avoid potential panic in choke_reset()Eric Dumazet1-1/+2
[ Upstream commit 8738c85c72b3108c9b9a369a39868ba5f8e10ae0 ] If choke_init() could not allocate q->tab, we would crash later in choke_reset(). BUG: KASAN: null-ptr-deref in memset include/linux/string.h:366 [inline] BUG: KASAN: null-ptr-deref in choke_reset+0x208/0x340 net/sched/sch_choke.c:326 Write of size 8 at addr 0000000000000000 by task syz-executor822/7022 CPU: 1 PID: 7022 Comm: syz-executor822 Not tainted 5.7.0-rc1-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+0x188/0x20d lib/dump_stack.c:118 __kasan_report.cold+0x5/0x4d mm/kasan/report.c:515 kasan_report+0x33/0x50 mm/kasan/common.c:625 check_memory_region_inline mm/kasan/generic.c:187 [inline] check_memory_region+0x141/0x190 mm/kasan/generic.c:193 memset+0x20/0x40 mm/kasan/common.c:85 memset include/linux/string.h:366 [inline] choke_reset+0x208/0x340 net/sched/sch_choke.c:326 qdisc_reset+0x6b/0x520 net/sched/sch_generic.c:910 dev_deactivate_queue.constprop.0+0x13c/0x240 net/sched/sch_generic.c:1138 netdev_for_each_tx_queue include/linux/netdevice.h:2197 [inline] dev_deactivate_many+0xe2/0xba0 net/sched/sch_generic.c:1195 dev_deactivate+0xf8/0x1c0 net/sched/sch_generic.c:1233 qdisc_graft+0xd25/0x1120 net/sched/sch_api.c:1051 tc_modify_qdisc+0xbab/0x1a00 net/sched/sch_api.c:1670 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5454 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2469 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6bf/0x7e0 net/socket.c:2362 ___sys_sendmsg+0x100/0x170 net/socket.c:2416 __sys_sendmsg+0xec/0x1b0 net/socket.c:2449 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 Fixes: 77e62da6e60c ("sch_choke: drop all packets in queue during reset") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20sch_sfq: validate silly quantum valuesEric Dumazet1-0/+9
[ Upstream commit df4953e4e997e273501339f607b77953772e3559 ] syzbot managed to set up sfq so that q->scaled_quantum was zero, triggering an infinite loop in sfq_dequeue() More generally, we must only accept quantum between 1 and 2^18 - 7, meaning scaled_quantum must be in [1, 0x7FFF] range. Otherwise, we also could have a loop in sfq_dequeue() if scaled_quantum happens to be 0x8000, since slot->allot could indefinitely switch between 0 and 0x8000. Fixes: eeaeb068f139 ("sch_sfq: allow big packets and be fair") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot+0251e883fe39e7a0cb0a@syzkaller.appspotmail.com Cc: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-10mac80211: add ieee80211_is_any_nullfunc()Thomas Pedersen4-10/+7
commit 30b2f0be23fb40e58d0ad2caf8702c2a44cda2e1 upstream. commit 08a5bdde3812 ("mac80211: consider QoS Null frames for STA_NULLFUNC_ACKED") Fixed a bug where we failed to take into account a nullfunc frame can be either non-QoS or QoS. It turns out there is at least one more bug in ieee80211_sta_tx_notify(), introduced in commit 7b6ddeaf27ec ("mac80211: use QoS NDP for AP probing"), where we forgot to check for the QoS variant and so assumed the QoS nullfunc frame never went out Fix this by adding a helper ieee80211_is_any_nullfunc() which consolidates the check for non-QoS and QoS nullfunc frames. Replace existing compound conditionals and add a couple more missing checks for QoS variant. Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com> Link: https://lore.kernel.org/r/20200114055940.18502-3-thomas@adapt-ip.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-10sctp: Fix SHUTDOWN CTSN Ack in the peer restart caseJere Leppänen1-1/+5
commit 12dfd78e3a74825e6f0bc8df7ef9f938fbc6bfe3 upstream. When starting shutdown in sctp_sf_do_dupcook_a(), get the value for SHUTDOWN Cumulative TSN Ack from the new association, which is reconstructed from the cookie, instead of the old association, which the peer doesn't have anymore. Otherwise the SHUTDOWN is either ignored or replied to with an ABORT by the peer because CTSN Ack doesn't match the peer's Initial TSN. Fixes: bdf6fa52f01b ("sctp: handle association restarts when the socket is closed.") Signed-off-by: Jere Leppänen <jere.leppanen@nokia.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-10net: skbuff: Remove errornous length validation in skb_vlan_pop()Shmulik Ladkani1-6/+4
commit 636c2628086e40c86dac7ddc84a1c4b4fcccc6e3 upstream. In 93515d53b1 "net: move vlan pop/push functions into common code" skb_vlan_pop was moved from its private location in openvswitch to skbuff common code. In case skb has non hw-accel vlan tag, the original 'pop_vlan()' assured that skb->len is sufficient (if skb->len < VLAN_ETH_HLEN then pop was considered a no-op). This validation was moved as is into the new common 'skb_vlan_pop'. Alas, in its original location (openvswitch), there was a guarantee that 'data' points to the mac_header, therefore the 'skb->len < VLAN_ETH_HLEN' condition made sense. However there's no such guarantee in the generic 'skb_vlan_pop'. For short packets received in rx path going through 'skb_vlan_pop', this causes 'skb_vlan_pop' to fail pop-ing a valid vlan hdr (in the non hw-accel case) or to fail moving next tag into hw-accel tag. Remove the 'skb->len < VLAN_ETH_HLEN' condition entirely: It is superfluous since inner '__skb_vlan_pop' already verifies there are VLAN_ETH_HLEN writable bytes at the mac_header. Note this presents a slight change to skb_vlan_pop() users: In case total length is smaller than VLAN_ETH_HLEN, skb_vlan_pop() now returns an error, as opposed to previous "no-op" behavior. Existing callers (e.g. tc act vlan, ovs) usually drop the packet if 'skb_vlan_pop' fails. Fixes: 93515d53b1 ("net: move vlan pop/push functions into common code") Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Cc: Pravin Shelar <pshelar@ovn.org> Reviewed-by: Pravin B Shelar <pshelar@ovn.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-10bridge: Fix problems around fdb entries pointing to the bridge deviceToshiaki Makita1-25/+27
commit 7bb90c3715a496c650b2e879225030f9dd9cfafb upstream. Adding fdb entries pointing to the bridge device uses fdb_insert(), which lacks various checks and does not respect added_by_user flag. As a result, some inconsistent behavior can happen: * Adding temporary entries succeeds but results in permanent entries. * Same goes for "dynamic" and "use". * Changing mac address of the bridge device causes deletion of user-added entries. * Replacing existing entries looks successful from userspace but actually not, regardless of NLM_F_EXCL flag. Use the same logic as other entries and fix them. Fixes: 3741873b4f73 ("bridge: allow adding of fdb entries pointing to the bridge device") Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>