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2018-08-14l2tp: fix unused function warningArnd Bergmann3-12/+4
Removing one of the callers of pppol2tp_session_get_sock caused a harmless warning in some configurations: net/l2tp/l2tp_ppp.c:142:21: 'pppol2tp_session_get_sock' defined but not used [-Wunused-function] Rather than adding another #ifdef here, using a proper IS_ENABLED() check makes the code more readable and avoids those warnings while letting the compiler figure out for itself which code is needed. This adds one pointer for the unused show() callback in struct l2tp_session, but that seems harmless. Fixes: b0e29063dcb3 ("l2tp: remove pppol2tp_session_ioctl()") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-13l2tp: use sk_dst_check() to avoid race on sk->sk_dst_cacheWei Wang1-1/+1
In l2tp code, if it is a L2TP_UDP_ENCAP tunnel, tunnel->sk points to a UDP socket. User could call sendmsg() on both this tunnel and the UDP socket itself concurrently. As l2tp_xmit_skb() holds socket lock and call __sk_dst_check() to refresh sk->sk_dst_cache, while udpv6_sendmsg() is lockless and call sk_dst_check() to refresh sk->sk_dst_cache, there could be a race and cause the dst cache to be freed multiple times. So we fix l2tp side code to always call sk_dst_check() to garantee xchg() is called when refreshing sk->sk_dst_cache to avoid race conditions. Syzkaller reported stack trace: BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] BUG: KASAN: use-after-free in atomic_fetch_add_unless include/linux/atomic.h:575 [inline] BUG: KASAN: use-after-free in atomic_add_unless include/linux/atomic.h:597 [inline] BUG: KASAN: use-after-free in dst_hold_safe include/net/dst.h:308 [inline] BUG: KASAN: use-after-free in ip6_hold_safe+0xe6/0x670 net/ipv6/route.c:1029 Read of size 4 at addr ffff8801aea9a880 by task syz-executor129/4829 CPU: 0 PID: 4829 Comm: syz-executor129 Not tainted 4.18.0-rc7-next-20180802+ #30 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+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] atomic_fetch_add_unless include/linux/atomic.h:575 [inline] atomic_add_unless include/linux/atomic.h:597 [inline] dst_hold_safe include/net/dst.h:308 [inline] ip6_hold_safe+0xe6/0x670 net/ipv6/route.c:1029 rt6_get_pcpu_route net/ipv6/route.c:1249 [inline] ip6_pol_route+0x354/0xd20 net/ipv6/route.c:1922 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2098 fib6_rule_lookup+0x283/0x890 net/ipv6/fib6_rules.c:122 ip6_route_output_flags+0x2c5/0x350 net/ipv6/route.c:2126 ip6_dst_lookup_tail+0x1278/0x1da0 net/ipv6/ip6_output.c:978 ip6_dst_lookup_flow+0xc8/0x270 net/ipv6/ip6_output.c:1079 ip6_sk_dst_lookup_flow+0x5ed/0xc50 net/ipv6/ip6_output.c:1117 udpv6_sendmsg+0x2163/0x36b0 net/ipv6/udp.c:1354 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:632 ___sys_sendmsg+0x51d/0x930 net/socket.c:2115 __sys_sendmmsg+0x240/0x6f0 net/socket.c:2210 __do_sys_sendmmsg net/socket.c:2239 [inline] __se_sys_sendmmsg net/socket.c:2236 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2236 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x446a29 Code: e8 ac b8 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f4de5532db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 0000000000446a29 RDX: 00000000000000b8 RSI: 0000000020001b00 RDI: 0000000000000003 RBP: 00000000006dcc30 R08: 00007f4de5533700 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc3c R13: 00007ffe2b830fdf R14: 00007f4de55339c0 R15: 0000000000000001 Fixes: 71b1391a4128 ("l2tp: ensure sk->dst is still valid") Reported-by: syzbot+05f840f3b04f211bad55@syzkaller.appspotmail.com Signed-off-by: Wei Wang <weiwan@google.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Cc: Guillaume Nault <g.nault@alphalink.fr> Cc: David Ahern <dsahern@gmail.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11l2tp: let pppol2tp_ioctl() fallback to dev_ioctl()Guillaume Nault1-1/+1
Return -ENOIOCTLCMD for unknown ioctl commands. This lets dev_ioctl() handle generic socket ioctls like SIOCGIFNAME or SIOCGIFINDEX. PF_PPPOX/PX_PROTO_OL2TP was one of the few socket types not honouring this mechanism. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11l2tp: zero out stats in pppol2tp_copy_stats()Guillaume Nault1-4/+3
Integrate memset(0) in pppol2tp_copy_stats() to avoid calling it manually every time. While there, constify 'stats'. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11l2tp: remove pppol2tp_session_ioctl()Guillaume Nault1-47/+3
pppol2tp_ioctl() has everything in place for handling PPPIOCGL2TPSTATS on session sockets. We just need to copy the stats and set ->session_id. As a side effect of sharing session and tunnel code, ->using_ipsec is properly set even when the request was made using a session socket. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11l2tp: remove pppol2tp_tunnel_ioctl()Guillaume Nault1-79/+53
Handle PPPIOCGL2TPSTATS in pppol2tp_ioctl() if the socket represents a tunnel. This one is a bit special because the caller may use the tunnel socket to retrieve statistics of one of its sessions. If the session_id is set, the corresponding session's statistics are returned, instead of those of the tunnel. This is handled by the new pppol2tp_tunnel_copy_stats() helper function. Set ->tunnel_id and ->using_ipsec out of the conditional, so that it can be used by the 'else' branch in the following patch. We cannot do that for ->session_id, because tunnel sockets have to report the value that was originally passed in 'stats.session_id', while session sockets have to report their own session_id. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11l2tp: handle PPPIOC[GS]MRU and PPPIOC[GS]FLAGS in pppol2tp_ioctl()Guillaume Nault1-29/+44
Let pppol2tp_ioctl() handle ioctl commands directly. It still relies on pppol2tp_{session,tunnel}_ioctl() for PPPIOCGL2TPSTATS. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11l2tp: simplify pppol2tp_ioctl()Guillaume Nault1-27/+6
* Drop test on 'sk': sock->sk cannot be NULL, or pppox_ioctl() could not have called us. * Drop test on 'SOCK_DEAD' state: if this flag was set, the socket would be in the process of being released and no ioctl could be running anymore. * Drop test on 'PPPOX_*' state: we depend on ->sk_user_data to get the session structure. If it is non-NULL, then the socket is connected. Testing for PPPOX_* is redundant. * Retrieve session using ->sk_user_data directly, instead of going through pppol2tp_sock_to_session(). This avoids grabbing a useless reference on the socket. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11l2tp: split l2tp_session_get()Guillaume Nault6-36/+36
l2tp_session_get() is used for two different purposes. If 'tunnel' is NULL, the session is searched globally in the supplied network namespace. Otherwise it is searched exclusively in the tunnel context. Callers always know the context in which they need to search the session. But some of them do provide both a namespace and a tunnel, making the semantic of the call unclear. This patch defines l2tp_tunnel_get_session() for lookups done in a tunnel and restricts l2tp_session_get() to namespace searches. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11l2tp: define l2tp_tunnel_uses_xfrm()Guillaume Nault3-10/+21
Use helper function to figure out if a tunnel is using ipsec. Also, avoid accessing ->sk_policy directly since it's RCU protected. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-05Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-4/+9
Lots of overlapping changes, mostly trivial in nature. The mlxsw conflict was resolving using the example resolution at: https://github.com/jpirko/linux_mlxsw/blob/combined_queue/drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.c Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-03l2tp: fix missing refcount drop in pppol2tp_tunnel_ioctl()Guillaume Nault1-4/+9
If 'session' is not NULL and is not a PPP pseudo-wire, then we fail to drop the reference taken by l2tp_session_get(). Fixes: ecd012e45ab5 ("l2tp: filter out non-PPP sessions in pppol2tp_tunnel_ioctl()") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-03l2tp: ignore L2TP_ATTR_MTUGuillaume Nault5-23/+9
This attribute's handling is broken. It can only be used when creating Ethernet pseudo-wires, in which case its value can be used as the initial MTU for the l2tpeth device. However, when handling update requests, L2TP_ATTR_MTU only modifies session->mtu. This value is never propagated to the l2tpeth device. Dump requests also return the value of session->mtu, which is not synchronised anymore with the device MTU. The same problem occurs if the device MTU is properly updated using the generic IFLA_MTU attribute. In this case, session->mtu is not updated, and L2TP_ATTR_MTU will report an invalid value again when dumping the session. It does not seem worthwhile to complexify l2tp_eth.c to synchronise session->mtu with the device MTU. Even the ip-l2tp manpage advises to use 'ip link' to initialise the MTU of l2tpeth devices (iproute2 does not handle L2TP_ATTR_MTU at all anyway). So let's just ignore it entirely. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-03l2tp: simplify MTU handling in l2tp_pppGuillaume Nault1-49/+18
The value of the session's .mtu field, as defined by pppol2tp_connect() or pppol2tp_session_create(), is later overwritten by pppol2tp_session_init() (unless getting the tunnel's socket PMTU fails). This field is then only used when setting the PPP channel's MTU in pppol2tp_connect(). Furthermore, the SIOC[GS]IFMTU ioctls only act on the session's .mtu without propagating this value to the PPP channel, making them useless. This patch initialises the PPP channel's MTU directly and ignores the session's .mtu entirely. MTU is still computed by subtracting the PPPOL2TP_HEADER_OVERHEAD constant. It is not optimal, but that doesn't really matter: po->chan.mtu is only used when the channel is part of a multilink PPP bundle. Running multilink PPP over packet switched networks is certainly not going to be efficient, so not picking the best MTU does not harm (in the worst case, packets will just be fragmented by the underlay). The SIOC[GS]IFMTU ioctls are removed entirely (as opposed to simply ignored), because these ioctls commands are part of the requests that should be handled generically by the socket layer. PX_PROTO_OL2TP was the only socket type abusing these ioctls. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-03l2tp: define l2tp_tunnel_dst_mtu()Guillaume Nault3-21/+26
Consolidate retrieval of tunnel's socket mtu in order to simplify l2tp_eth and l2tp_ppp a bit. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27l2tp: drop ->mru from struct l2tp_sessionGuillaume Nault5-50/+8
This field is not used. Treat PPPIOC*MRU the same way as PPPIOC*FLAGS: "get" requests return 0, while "set" requests vadidate the user supplied pointer but discard its value. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27l2tp: drop ->flags from struct pppol2tp_sessionGuillaume Nault1-11/+2
This field is not used. Keep validating user input in PPPIOCSFLAGS. Even though we discard the value, it would look wrong to succeed if an invalid address was passed from userspace. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27l2tp: ignore L2TP_ATTR_VLAN_ID netlink attributeGuillaume Nault2-4/+0
The value of this attribute is never used. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27l2tp: ignore L2TP_ATTR_DATA_SEQ netlink attributeGuillaume Nault3-17/+1
The value of this attribute is never used. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27l2tp: remove ->recv_payload_hookGuillaume Nault5-39/+18
The tunnel reception hook is only used by l2tp_ppp for skipping PPP framing bytes. This is a session specific operation, but once a PPP session sets ->recv_payload_hook on its tunnel, all frames received by the tunnel will enter pppol2tp_recv_payload_hook(), including those targeted at Ethernet sessions (an L2TPv3 tunnel can multiplex PPP and Ethernet sessions). So this mechanism is wrong, and uselessly complex. Let's just move this functionality to the pppol2tp rx handler and drop ->recv_payload_hook. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-25l2tp: remove trailing newlineStephen Hemminger1-1/+0
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-07ipv6: fold sockcm_cookie into ipcm6_cookieWillem de Bruijn1-4/+2
ipcm_cookie includes sockcm_cookie. Do the same for ipcm6_cookie. This reduces the number of arguments that need to be passed around, applies ipcm6_init to all cookie fields at once and reduces code differentiation between ipv4 and ipv6. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-07ipv6: ipcm6_cookie initializerWillem de Bruijn1-3/+1
Initialize the cookie in one location to reduce code duplication and avoid bugs from inconsistent initialization, such as that fixed in commit 9887cba19978 ("ip: limit use of gso_size to udp"). Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-03Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/netDavid S. Miller3-3/+3
Simple overlapping changes in stmmac driver. Adjust skb_gro_flush_final_remcsum function signature to make GRO list changes in net-next, as per Stephen Rothwell's example merge resolution. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-28Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLLLinus Torvalds3-3/+3
The poll() changes were not well thought out, and completely unexplained. They also caused a huge performance regression, because "->poll()" was no longer a trivial file operation that just called down to the underlying file operations, but instead did at least two indirect calls. Indirect calls are sadly slow now with the Spectre mitigation, but the performance problem could at least be largely mitigated by changing the "->get_poll_head()" operation to just have a per-file-descriptor pointer to the poll head instead. That gets rid of one of the new indirections. But that doesn't fix the new complexity that is completely unwarranted for the regular case. The (undocumented) reason for the poll() changes was some alleged AIO poll race fixing, but we don't make the common case slower and more complex for some uncommon special case, so this all really needs way more explanations and most likely a fundamental redesign. [ This revert is a revert of about 30 different commits, not reverted individually because that would just be unnecessarily messy - Linus ] Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-28l2tp: define helper for parsing struct sockaddr_pppol2tp*Guillaume Nault1-70/+103
'sockaddr_len' is checked against various values when entering pppol2tp_connect(), to verify its validity. It is used again later, to find out which sockaddr structure was passed from user space. This patch combines these two operations into one new function in order to simplify pppol2tp_connect(). A new structure, l2tp_connect_info, is used to pass sockaddr data back to pppol2tp_connect(), to avoid passing too many parameters to l2tp_sockaddr_get_info(). Also, the first parameter is void* in order to avoid casting between all sockaddr_* structures manually. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: make l2tp_xmit_core() return voidGuillaume Nault1-4/+2
It always returns 0, and nobody reads the return value anyway. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: avoid duplicate l2tp_pernet() callsGuillaume Nault1-2/+1
Replace 'l2tp_pernet(tunnel->l2tp_net)' with 'pn', which has been set on the preceding line. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: don't export l2tp_tunnel_closeall()Guillaume Nault2-3/+1
This function is only used in l2tp_core.c. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: don't export l2tp_session_queue_purge()Guillaume Nault2-3/+1
This function is only used in l2tp_core.c. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: remove l2tp_tunnel_priv()Guillaume Nault1-7/+0
This function, and the associated .priv field, are unused. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: remove .show from struct l2tp_tunnelGuillaume Nault2-6/+0
This callback has never been implemented. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26l2tp: remove pppol2tp_session_close()Guillaume Nault1-7/+0
l2tp_core.c verifies that ->session_close() is defined before calling it. There's no need for a stub. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-15l2tp: filter out non-PPP sessions in pppol2tp_tunnel_ioctl()Guillaume Nault1-1/+1
pppol2tp_tunnel_ioctl() can act on an L2TPv3 tunnel, in which case 'session' may be an Ethernet pseudo-wire. However, pppol2tp_session_ioctl() expects a PPP pseudo-wire, as it assumes l2tp_session_priv() points to a pppol2tp_session structure. For an Ethernet pseudo-wire l2tp_session_priv() points to an l2tp_eth_sess structure instead, making pppol2tp_session_ioctl() access invalid memory. 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>
2018-06-15l2tp: reject creation of non-PPP sessions on L2TPv2 tunnelsGuillaume Nault1-0/+6
The /proc/net/pppol2tp handlers (pppol2tp_seq_*()) iterate over all L2TPv2 tunnels, and rightfully expect that only PPP sessions can be found there. However, l2tp_netlink accepts creating Ethernet sessions regardless of the underlying tunnel version. This confuses pppol2tp_seq_session_show(), which expects that l2tp_session_priv() returns a pppol2tp_session structure. When the session is an Ethernet pseudo-wire, a struct l2tp_eth_sess is returned instead. This leads to invalid memory access when pppol2tp_session_get_sock() later tries to dereference ps->sk. 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>
2018-06-15l2tp: clean up stale tunnel or session in pppol2tp_connect's error pathGuillaume Nault1-0/+10
pppol2tp_connect() may create a tunnel or a session. Remove them in case of error. 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>
2018-06-15l2tp: prevent pppol2tp_connect() from creating kernel socketsGuillaume Nault1-0/+9
If 'fd' is negative, l2tp_tunnel_create() creates a tunnel socket using the configuration passed in 'tcfg'. Currently, pppol2tp_connect() sets the relevant fields to zero, tricking l2tp_tunnel_create() into setting up an unusable kernel socket. We can't set 'tcfg' with the required fields because there's no way to get them from the current connect() parameters. So let's restrict kernel sockets creation to the netlink API, which is the original use case. Fixes: 789a4a2c61d8 ("l2tp: Add support for static unmanaged L2TPv3 tunnels") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-15l2tp: only accept PPP sessions in pppol2tp_connect()Guillaume Nault1-0/+6
l2tp_session_priv() returns a struct pppol2tp_session pointer only for PPPoL2TP sessions. In particular, if the session is an L2TP_PWTYPE_ETH pseudo-wire, l2tp_session_priv() returns a pointer to an l2tp_eth_sess structure, which is much smaller than struct pppol2tp_session. This leads to invalid memory dereference when trying to lock ps->sk_lock. 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>
2018-06-15l2tp: fix pseudo-wire type for sessions created by pppol2tp_connect()Guillaume Nault1-0/+1
Define cfg.pw_type so that the new session is created with its .pwtype field properly set (L2TP_PWTYPE_PPP). Not setting the pseudo-wire type had several annoying effects: * Invalid value returned in the L2TP_ATTR_PW_TYPE attribute when dumping sessions with the netlink API. * Impossibility to delete the session using the netlink API (because l2tp_nl_cmd_session_delete() gets the deletion callback function from an array indexed by the session's pseudo-wire type). Also, there are several cases where we should check a session's pseudo-wire type. For example, pppol2tp_connect() should refuse to connect a session that is not PPPoL2TP, but that requires the session's .pwtype field to be properly set. Fixes: f7faffa3ff8e ("l2tp: Add L2TPv3 protocol support") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds2-33/+43
Pull networking updates from David Miller: 1) Add Maglev hashing scheduler to IPVS, from Inju Song. 2) Lots of new TC subsystem tests from Roman Mashak. 3) Add TCP zero copy receive and fix delayed acks and autotuning with SO_RCVLOWAT, from Eric Dumazet. 4) Add XDP_REDIRECT support to mlx5 driver, from Jesper Dangaard Brouer. 5) Add ttl inherit support to vxlan, from Hangbin Liu. 6) Properly separate ipv6 routes into their logically independant components. fib6_info for the routing table, and fib6_nh for sets of nexthops, which thus can be shared. From David Ahern. 7) Add bpf_xdp_adjust_tail helper, which can be used to generate ICMP messages from XDP programs. From Nikita V. Shirokov. 8) Lots of long overdue cleanups to the r8169 driver, from Heiner Kallweit. 9) Add BTF ("BPF Type Format"), from Martin KaFai Lau. 10) Add traffic condition monitoring to iwlwifi, from Luca Coelho. 11) Plumb extack down into fib_rules, from Roopa Prabhu. 12) Add Flower classifier offload support to igb, from Vinicius Costa Gomes. 13) Add UDP GSO support, from Willem de Bruijn. 14) Add documentation for eBPF helpers, from Quentin Monnet. 15) Add TLS tx offload to mlx5, from Ilya Lesokhin. 16) Allow applications to be given the number of bytes available to read on a socket via a control message returned from recvmsg(), from Soheil Hassas Yeganeh. 17) Add x86_32 eBPF JIT compiler, from Wang YanQing. 18) Add AF_XDP sockets, with zerocopy support infrastructure as well. From Björn Töpel. 19) Remove indirect load support from all of the BPF JITs and handle these operations in the verifier by translating them into native BPF instead. From Daniel Borkmann. 20) Add GRO support to ipv6 gre tunnels, from Eran Ben Elisha. 21) Allow XDP programs to do lookups in the main kernel routing tables for forwarding. From David Ahern. 22) Allow drivers to store hardware state into an ELF section of kernel dump vmcore files, and use it in cxgb4. From Rahul Lakkireddy. 23) Various RACK and loss detection improvements in TCP, from Yuchung Cheng. 24) Add TCP SACK compression, from Eric Dumazet. 25) Add User Mode Helper support and basic bpfilter infrastructure, from Alexei Starovoitov. 26) Support ports and protocol values in RTM_GETROUTE, from Roopa Prabhu. 27) Support bulking in ->ndo_xdp_xmit() API, from Jesper Dangaard Brouer. 28) Add lots of forwarding selftests, from Petr Machata. 29) Add generic network device failover driver, from Sridhar Samudrala. * ra.kernel.org:/pub/scm/linux/kernel/git/davem/net-next: (1959 commits) strparser: Add __strp_unpause and use it in ktls. rxrpc: Fix terminal retransmission connection ID to include the channel net: hns3: Optimize PF CMDQ interrupt switching process net: hns3: Fix for VF mailbox receiving unknown message net: hns3: Fix for VF mailbox cannot receiving PF response bnx2x: use the right constant Revert "net: sched: cls: Fix offloading when ingress dev is vxlan" net: dsa: b53: Fix for brcm tag issue in Cygnus SoC enic: fix UDP rss bits netdev-FAQ: clarify DaveM's position for stable backports rtnetlink: validate attributes in do_setlink() mlxsw: Add extack messages for port_{un, }split failures netdevsim: Add extack error message for devlink reload devlink: Add extack to reload and port_{un, }split operations net: metrics: add proper netlink validation ipmr: fix error path when ipmr_new_table fails ip6mr: only set ip6mr_table from setsockopt when ip6mr_new_table succeeds net: hns3: remove unused hclgevf_cfg_func_mta_filter netfilter: provide udp*_lib_lookup for nf_tproxy qed*: Utilize FW 8.37.2.0 ...
2018-06-05l2tp: fix refcount leakage on PPPoL2TP socketsGuillaume Nault1-18/+17
Commit d02ba2a6110c ("l2tp: fix race in pppol2tp_release with session object destroy") tried to fix a race condition where a PPPoL2TP socket would disappear while the L2TP session was still using it. However, it missed the root issue which is that an L2TP session may accept to be reconnected if its associated socket has entered the release process. The tentative fix makes the session hold the socket it is connected to. That saves the kernel from crashing, but introduces refcount leakage, preventing the socket from completing the release process. Once stalled, everything the socket depends on can't be released anymore, including the L2TP session and the l2tp_ppp module. The root issue is that, when releasing a connected PPPoL2TP socket, the session's ->sk pointer (RCU-protected) is reset to NULL and we have to wait for a grace period before destroying the socket. The socket drops the session in its ->sk_destruct callback function, so the session will exist until the last reference on the socket is dropped. Therefore, there is a time frame where pppol2tp_connect() may accept reconnecting a session, as it only checks ->sk to figure out if the session is connected. This time frame is shortened by the fact that pppol2tp_release() calls l2tp_session_delete(), making the session unreachable before resetting ->sk. However, pppol2tp_connect() may grab the session before it gets unhashed by l2tp_session_delete(), but it may test ->sk after the later got reset. The race is not so hard to trigger and syzbot found a pretty reliable reproducer: https://syzkaller.appspot.com/bug?id=418578d2a4389074524e04d641eacb091961b2cf Before d02ba2a6110c, another race could let pppol2tp_release() overwrite the ->__sk pointer of an L2TP session, thus tricking pppol2tp_put_sk() into calling sock_put() on a socket that is different than the one for which pppol2tp_release() was originally called. To get there, we had to trigger the race described above, therefore having one PPPoL2TP socket being released, while the session it is connected to is reconnecting to a different PPPoL2TP socket. When releasing this new socket fast enough, pppol2tp_release() overwrites the session's ->__sk pointer with the address of the new socket, before the first pppol2tp_put_sk() call gets scheduled. Then the pppol2tp_put_sk() call invoked by the original socket will sock_put() the new socket, potentially dropping its last reference. When the second pppol2tp_put_sk() finally runs, its socket has already been freed. With d02ba2a6110c, the session takes a reference on both sockets. Furthermore, the session's ->sk pointer is reset in the pppol2tp_session_close() callback function rather than in pppol2tp_release(). Therefore, ->__sk can't be overwritten and pppol2tp_put_sk() is called only once (l2tp_session_delete() will only run pppol2tp_session_close() once, to protect the session against concurrent deletion requests). Now pppol2tp_put_sk() will properly sock_put() the original socket, but the new socket will remain, as l2tp_session_delete() prevented the release process from completing. Here, we don't depend on the ->__sk race to trigger the bug. Getting into the pppol2tp_connect() race is enough to leak the reference, no matter when new socket is released. So it all boils down to pppol2tp_connect() failing to realise that the session has already been connected. This patch drops the unneeded extra reference counting (mostly reverting d02ba2a6110c) and checks that neither ->sk nor ->__sk is set before allowing a session to be connected. Fixes: d02ba2a6110c ("l2tp: fix race in pppol2tp_release with session object destroy") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-04Merge branch 'work.aio-1' of ↵Linus Torvalds3-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull aio updates from Al Viro: "Majority of AIO stuff this cycle. aio-fsync and aio-poll, mostly. The only thing I'm holding back for a day or so is Adam's aio ioprio - his last-minute fixup is trivial (missing stub in !CONFIG_BLOCK case), but let it sit in -next for decency sake..." * 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits) aio: sanitize the limit checking in io_submit(2) aio: fold do_io_submit() into callers aio: shift copyin of iocb into io_submit_one() aio_read_events_ring(): make a bit more readable aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way aio: take list removal to (some) callers of aio_complete() aio: add missing break for the IOCB_CMD_FDSYNC case random: convert to ->poll_mask timerfd: convert to ->poll_mask eventfd: switch to ->poll_mask pipe: convert to ->poll_mask crypto: af_alg: convert to ->poll_mask net/rxrpc: convert to ->poll_mask net/iucv: convert to ->poll_mask net/phonet: convert to ->poll_mask net/nfc: convert to ->poll_mask net/caif: convert to ->poll_mask net/bluetooth: convert to ->poll_mask net/sctp: convert to ->poll_mask net/tipc: convert to ->poll_mask ...
2018-05-26net: convert datagram_poll users tp ->poll_maskChristoph Hellwig3-3/+3
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-16proc: introduce proc_create_net{,_data}Christoph Hellwig1-20/+2
Variants of proc_create{,_data} that directly take a struct seq_operations and deal with network namespaces in ->open and ->release. All callers of proc_create + seq_open_net converted over, and seq_{open,release}_net are removed entirely. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-04-27l2tp: consistent reference counting in procfs and debufsGuillaume Nault2-15/+26
The 'pppol2tp' procfs and 'l2tp/tunnels' debugfs files handle reference counting of sessions differently than for tunnels. For consistency, use the same mechanism for handling both sessions and tunnels. That is, drop the reference on the previous session just before looking up the next one (rather than in .show()). If necessary (if dump stops before *_next_session() returns NULL), drop the last reference in .stop(). Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-24l2tp: check sockaddr length in pppol2tp_connect()Guillaume Nault1-0/+7
Check sockaddr_len before dereferencing sp->sa_protocol, to ensure that it actually points to valid data. Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Reported-by: syzbot+a70ac890b23b1bf29f5c@syzkaller.appspotmail.com Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-22l2tp: fix {pppol2tp, l2tp_dfs}_seq_stop() in case of seq_file overflowGuillaume Nault2-2/+8
Commit 0e0c3fee3a59 ("l2tp: hold reference on tunnels printed in pppol2tp proc file") assumed that if pppol2tp_seq_stop() was called with non-NULL private data (the 'v' pointer), then pppol2tp_seq_start() would not be called again. It turns out that this isn't guaranteed, and overflowing the seq_file's buffer in pppol2tp_seq_show() is a way to get into this situation. Therefore, pppol2tp_seq_stop() needs to reset pd->tunnel, so that pppol2tp_seq_start() won't drop a reference again if it gets called. We also have to clear pd->session, because the rest of the code expects a non-NULL tunnel when pd->session is set. The l2tp_debugfs module has the same issue. Fix it in the same way. Fixes: 0e0c3fee3a59 ("l2tp: hold reference on tunnels printed in pppol2tp proc file") Fixes: f726214d9b23 ("l2tp: hold reference on tunnels printed in l2tp/tunnels debugfs file") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-13l2tp: hold reference on tunnels printed in l2tp/tunnels debugfs fileGuillaume Nault3-23/+13
Use l2tp_tunnel_get_nth() instead of l2tp_tunnel_find_nth(), to be safe against concurrent tunnel deletion. Use the same mechanism as in l2tp_ppp.c for dropping the reference taken by l2tp_tunnel_get_nth(). That is, drop the reference just before looking up the next tunnel. In case of error, drop the last accessed tunnel in l2tp_dfs_seq_stop(). That was the last use of l2tp_tunnel_find_nth(). Fixes: 0ad6614048cf ("l2tp: Add debugfs files for dumping l2tp debug info") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-13l2tp: hold reference on tunnels printed in pppol2tp proc fileGuillaume Nault1-7/+17
Use l2tp_tunnel_get_nth() instead of l2tp_tunnel_find_nth(), to be safe against concurrent tunnel deletion. Unlike sessions, we can't drop the reference held on tunnels in pppol2tp_seq_show(). Tunnels are reused across several calls to pppol2tp_seq_start() when iterating over sessions. These iterations need the tunnel for accessing the next session. Therefore the only safe moment for dropping the reference is just before searching for the next tunnel. Normally, the last invocation of pppol2tp_next_tunnel() doesn't find any new tunnel, so it drops the last tunnel without taking any new reference. However, in case of error, pppol2tp_seq_stop() is called directly, so we have to drop the reference there. 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>
2018-04-13l2tp: hold reference on tunnels in netlink dumpsGuillaume Nault3-3/+30
l2tp_tunnel_find_nth() is unsafe: no reference is held on the returned tunnel, therefore it can be freed whenever the caller uses it. This patch defines l2tp_tunnel_get_nth() which works similarly, but also takes a reference on the returned tunnel. The caller then has to drop it after it stops using the tunnel. Convert netlink dumps to make them safe against concurrent tunnel deletion. 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>
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