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2019-03-19l2tp: fix infoleak in l2tp_ip6_recvmsg()Eric Dumazet
[ Upstream commit 163d1c3d6f17556ed3c340d3789ea93be95d6c28 ] Back in 2013 Hannes took care of most of such leaks in commit bceaa90240b6 ("inet: prevent leakage of uninitialized memory to user in recv syscalls") But the bug in l2tp_ip6_recvmsg() has not been fixed. syzbot report : BUG: KMSAN: kernel-infoleak in _copy_to_user+0x16b/0x1f0 lib/usercopy.c:32 CPU: 1 PID: 10996 Comm: syz-executor362 Not tainted 5.0.0+ #11 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+0x173/0x1d0 lib/dump_stack.c:113 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:600 kmsan_internal_check_memory+0x9f4/0xb10 mm/kmsan/kmsan.c:694 kmsan_copy_to_user+0xab/0xc0 mm/kmsan/kmsan_hooks.c:601 _copy_to_user+0x16b/0x1f0 lib/usercopy.c:32 copy_to_user include/linux/uaccess.h:174 [inline] move_addr_to_user+0x311/0x570 net/socket.c:227 ___sys_recvmsg+0xb65/0x1310 net/socket.c:2283 do_recvmmsg+0x646/0x10c0 net/socket.c:2390 __sys_recvmmsg net/socket.c:2469 [inline] __do_sys_recvmmsg net/socket.c:2492 [inline] __se_sys_recvmmsg+0x1d1/0x350 net/socket.c:2485 __x64_sys_recvmmsg+0x62/0x80 net/socket.c:2485 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x445819 Code: e8 6c b6 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 2b 12 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f64453eddb8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00000000006dac28 RCX: 0000000000445819 RDX: 0000000000000005 RSI: 0000000020002f80 RDI: 0000000000000003 RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac2c R13: 00007ffeba8f87af R14: 00007f64453ee9c0 R15: 20c49ba5e353f7cf Local variable description: ----addr@___sys_recvmsg Variable was created at: ___sys_recvmsg+0xf6/0x1310 net/socket.c:2244 do_recvmmsg+0x646/0x10c0 net/socket.c:2390 Bytes 0-31 of 32 are uninitialized Memory access of size 32 starts at ffff8880ae62fbb0 Data copied to user address 0000000020000000 Fixes: a32e0eec7042 ("l2tp: introduce L2TPv3 IP encapsulation support for IPv6") 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>
2019-02-06l2tp: fix reading optional fields of L2TPv3Jacob Wen
[ Upstream commit 4522a70db7aa5e77526a4079628578599821b193 ] Use pskb_may_pull() to make sure the optional fields are in skb linear parts, so we can safely read them later. It's easy to reproduce the issue with a net driver that supports paged skb data. Just create a L2TPv3 over IP tunnel and then generates some network traffic. Once reproduced, rx err in /sys/kernel/debug/l2tp/tunnels will increase. Changes in v4: 1. s/l2tp_v3_pull_opt/l2tp_v3_ensure_opt_in_linear/ 2. s/tunnel->version != L2TP_HDR_VER_2/tunnel->version == L2TP_HDR_VER_3/ 3. Add 'Fixes' in commit messages. Changes in v3: 1. To keep consistency, move the code out of l2tp_recv_common. 2. Use "net" instead of "net-next", since this is a bug fix. Changes in v2: 1. Only fix L2TPv3 to make code simple. To fix both L2TPv3 and L2TPv2, we'd better refactor l2tp_recv_common. It's complicated to do so. 2. Reloading pointers after pskb_may_pull Fixes: f7faffa3ff8e ("l2tp: Add L2TPv3 protocol support") Fixes: 0d76751fad77 ("l2tp: Add L2TPv3 IP encapsulation (no UDP) support") Fixes: a32e0eec7042 ("l2tp: introduce L2TPv3 IP encapsulation support for IPv6") Signed-off-by: Jacob Wen <jian.w.wen@oracle.com> Acked-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06l2tp: remove l2specific_len dependency in l2tp_coreLorenzo Bianconi
commit 62e7b6a57c7b9bf3c6fd99418eeec05b08a85c38 upstream. Remove l2specific_len dependency while building l2tpv3 header or parsing the received frame since default L2-Specific Sublayer is always four bytes long and we don't need to rely on a user supplied value. Moreover in l2tp netlink code there are no sanity checks to enforce the relation between l2specific_len and l2specific_type, so sending a malformed netlink message is possible to set l2specific_type to L2TP_L2SPECTYPE_DEFAULT (or even L2TP_L2SPECTYPE_NONE) and set l2specific_len to a value greater than 4 leaking memory on the wire and sending corrupted frames. Reviewed-by: Guillaume Nault <g.nault@alphalink.fr> Tested-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06l2tp: copy 4 more bytes to linear part if necessaryJacob Wen
[ Upstream commit 91c524708de6207f59dd3512518d8a1c7b434ee3 ] The size of L2TPv2 header with all optional fields is 14 bytes. l2tp_udp_recv_core only moves 10 bytes to the linear part of a skb. This may lead to l2tp_recv_common read data outside of a skb. This patch make sure that there is at least 14 bytes in the linear part of a skb to meet the maximum need of l2tp_udp_recv_core and l2tp_recv_common. The minimum size of both PPP HDLC-like frame and Ethernet frame is larger than 14 bytes, so we are safe to do so. Also remove L2TP_HDR_SIZE_NOSEQ, it is unused now. Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Suggested-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Jacob Wen <jian.w.wen@oracle.com> Acked-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-04l2tp: remove configurable payload offsetJames Chapman
[ Upstream commit 900631ee6a2651dc4fbaecb8ef9fa5f1e3378853 ] If L2TP_ATTR_OFFSET is set to a non-zero value in L2TPv3 tunnels, it results in L2TPv3 packets being transmitted which might not be compliant with the L2TPv3 RFC. This patch has l2tp ignore the offset setting and send all packets with no offset. In more detail: L2TPv2 supports a variable offset from the L2TPv2 header to the payload. The offset value is indicated by an optional field in the L2TP header. Our L2TP implementation already detects the presence of the optional offset and skips that many bytes when handling data received packets. All transmitted packets are always transmitted with no offset. L2TPv3 has no optional offset field in the L2TPv3 packet header. Instead, L2TPv3 defines optional fields in a "Layer-2 Specific Sublayer". At the time when the original L2TP code was written, there was talk at IETF of offset being implemented in a new Layer-2 Specific Sublayer. A L2TP_ATTR_OFFSET netlink attribute was added so that this offset could be configured and the intention was to allow it to be also used to set the tx offset for L2TPv2. However, no L2TPv3 offset was ever specified and the L2TP_ATTR_OFFSET parameter was forgotten about. Setting L2TP_ATTR_OFFSET results in L2TPv3 packets being transmitted with the specified number of bytes padding between L2TPv3 header and payload. This is not compliant with L2TPv3 RFC3931. This change removes the configurable offset altogether while retaining L2TP_ATTR_OFFSET for backwards compatibility. Any L2TP_ATTR_OFFSET value is ignored. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-08-22l2tp: use sk_dst_check() to avoid race on sk->sk_dst_cacheWei Wang
[ Upstream commit 6d37fa49da1e8db8fb1995be22ac837ca41ac8a8 ] 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-19l2tp: revert "l2tp: fix missing print session offset info"James Chapman
commit de3b58bc359a861d5132300f53f95e83f71954b3 upstream. Revert commit 820da5357572 ("l2tp: fix missing print session offset info"). The peer_offset parameter is removed. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29l2tp: check sockaddr length in pppol2tp_connect()Guillaume Nault
[ Upstream commit eb1c28c05894a4b1f6b56c5bf072205e64cfa280 ] 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-12l2tp: fix missing print session offset infoHangbin Liu
[ Upstream commit 820da5357572715c6235ba3b3daa2d5b43a1198f ] Report offset parameter in L2TP_CMD_SESSION_GET command if it has been configured by userspace Fixes: 309795f4bec ("l2tp: Add netlink control API for L2TP") Reported-by: Jianlin Shi <jishi@redhat.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-08l2tp: fix races with ipv4-mapped ipv6 addressesPaolo Abeni
commit b954f94023dcc61388c8384f0f14eb8e42c863c5 upstream. The l2tp_tunnel_create() function checks for v4mapped ipv6 sockets and cache that flag, so that l2tp core code can reusing it at xmit time. If the socket is provided by the userspace, the connection status of the tunnel sockets can change between the tunnel creation and the xmit call, so that syzbot is able to trigger the following splat: BUG: KASAN: use-after-free in ip6_dst_idev include/net/ip6_fib.h:192 [inline] BUG: KASAN: use-after-free in ip6_xmit+0x1f76/0x2260 net/ipv6/ip6_output.c:264 Read of size 8 at addr ffff8801bd949318 by task syz-executor4/23448 CPU: 0 PID: 23448 Comm: syz-executor4 Not tainted 4.16.0-rc4+ #65 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report+0x23c/0x360 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 ip6_dst_idev include/net/ip6_fib.h:192 [inline] ip6_xmit+0x1f76/0x2260 net/ipv6/ip6_output.c:264 inet6_csk_xmit+0x2fc/0x580 net/ipv6/inet6_connection_sock.c:139 l2tp_xmit_core net/l2tp/l2tp_core.c:1053 [inline] l2tp_xmit_skb+0x105f/0x1410 net/l2tp/l2tp_core.c:1148 pppol2tp_sendmsg+0x470/0x670 net/l2tp/l2tp_ppp.c:341 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg+0xca/0x110 net/socket.c:640 ___sys_sendmsg+0x767/0x8b0 net/socket.c:2046 __sys_sendmsg+0xe5/0x210 net/socket.c:2080 SYSC_sendmsg net/socket.c:2091 [inline] SyS_sendmsg+0x2d/0x50 net/socket.c:2087 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453e69 RSP: 002b:00007f819593cc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f819593d6d4 RCX: 0000000000453e69 RDX: 0000000000000081 RSI: 000000002037ffc8 RDI: 0000000000000004 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000004c3 R14: 00000000006f72e8 R15: 0000000000000000 This change addresses the issues: * explicitly checking for TCP_ESTABLISHED for user space provided sockets * dropping the v4mapped flag usage - it can become outdated - and explicitly invoking ipv6_addr_v4mapped() instead The issue is apparently there since ancient times. v1 -> v2: (many thanks to Guillaume) - with csum issue introduced in v1 - replace pr_err with pr_debug - fix build issue with IPV6 disabled - move l2tp_sk_is_v4mapped in l2tp_core.c v2 -> v3: - don't update inet_daddr for v4mapped address, unneeded - drop rendundant check at creation time Reported-and-tested-by: syzbot+92fa328176eb07e4ac1a@syzkaller.appspotmail.com Fixes: 3557baabf280 ("[L2TP]: PPP over L2TP driver core") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-31l2tp: do not accept arbitrary socketsEric Dumazet
[ Upstream commit 17cfe79a65f98abe535261856c5aef14f306dff7 ] syzkaller found an issue caused by lack of sufficient checks in l2tp_tunnel_create() RAW sockets can not be considered as UDP ones for instance. In another patch, we shall replace all pr_err() by less intrusive pr_debug() so that syzkaller can find other bugs faster. Acked-by: Guillaume Nault <g.nault@alphalink.fr> Acked-by: James Chapman <jchapman@katalix.com> ================================================================== BUG: KASAN: slab-out-of-bounds in setup_udp_tunnel_sock+0x3ee/0x5f0 net/ipv4/udp_tunnel.c:69 dst_release: dst:00000000d53d0d0f refcnt:-1 Write of size 1 at addr ffff8801d013b798 by task syz-executor3/6242 CPU: 1 PID: 6242 Comm: syz-executor3 Not tainted 4.16.0-rc2+ #253 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report+0x23b/0x360 mm/kasan/report.c:412 __asan_report_store1_noabort+0x17/0x20 mm/kasan/report.c:435 setup_udp_tunnel_sock+0x3ee/0x5f0 net/ipv4/udp_tunnel.c:69 l2tp_tunnel_create+0x1354/0x17f0 net/l2tp/l2tp_core.c:1596 pppol2tp_connect+0x14b1/0x1dd0 net/l2tp/l2tp_ppp.c:707 SYSC_connect+0x213/0x4a0 net/socket.c:1640 SyS_connect+0x24/0x30 net/socket.c:1621 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") 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>
2017-12-20l2tp: cleanup l2tp_tunnel_delete callsJiri Slaby
[ Upstream commit 4dc12ffeaeac939097a3f55c881d3dc3523dff0c ] l2tp_tunnel_delete does not return anything since commit 62b982eeb458 ("l2tp: fix race condition in l2tp_tunnel_delete"). But call sites of l2tp_tunnel_delete still do casts to void to avoid unused return value warnings. Kill these now useless casts. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Sabrina Dubroca <sd@queasysnail.net> Cc: Guillaume Nault <g.nault@alphalink.fr> Cc: David S. Miller <davem@davemloft.net> Cc: netdev@vger.kernel.org Acked-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-05l2tp: don't use l2tp_tunnel_find() in l2tp_ip and l2tp_ip6Guillaume Nault
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>
2017-11-02Merge tag 'spdx_identifiers-4.14-rc8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull initial SPDX identifiers from Greg KH: "License cleanup: add SPDX license identifiers to some files Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" * tag 'spdx_identifiers-4.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: License cleanup: add SPDX license identifier to uapi header files with a license License cleanup: add SPDX license identifier to uapi header files with no license License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-31l2tp: hold tunnel in pppol2tp_connect()Guillaume Nault
Use l2tp_tunnel_get() in pppol2tp_connect() to ensure the tunnel isn't going to disappear while processing the rest of the function. 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>
2017-10-14l2tp: check ps->sock before running pppol2tp_session_ioctl()Guillaume Nault
When pppol2tp_session_ioctl() is called by pppol2tp_tunnel_ioctl(), the session may be unconnected. That is, it was created by pppol2tp_session_create() and hasn't been connected with pppol2tp_connect(). In this case, ps->sock is NULL, so we need to check for this case in order to avoid dereferencing a NULL pointer. 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>
2017-10-01l2tp: fix l2tp_eth module loadingGuillaume Nault
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>
2017-09-26l2tp: fix race condition in l2tp_tunnel_deleteSabrina Dubroca
If we try to delete the same tunnel twice, the first delete operation does a lookup (l2tp_tunnel_get), finds the tunnel, calls l2tp_tunnel_delete, which queues it for deletion by l2tp_tunnel_del_work. The second delete operation also finds the tunnel and calls l2tp_tunnel_delete. If the workqueue has already fired and started running l2tp_tunnel_del_work, then l2tp_tunnel_delete will queue the same tunnel a second time, and try to free the socket again. Add a dead flag to prevent firing the workqueue twice. Then we can remove the check of queue_work's result that was meant to prevent that race but doesn't. Reproducer: ip l2tp add tunnel tunnel_id 3000 peer_tunnel_id 4000 local 192.168.0.2 remote 192.168.0.1 encap udp udp_sport 5000 udp_dport 6000 ip l2tp add session name l2tp1 tunnel_id 3000 session_id 1000 peer_session_id 2000 ip link set l2tp1 up ip l2tp del tunnel tunnel_id 3000 ip l2tp del tunnel tunnel_id 3000 Fixes: f8ccac0e4493 ("l2tp: put tunnel socket release on a workqueue") Reported-by: Jianlin Shi <jishi@redhat.com> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Acked-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-25l2tp: fix race between l2tp_session_delete() and l2tp_tunnel_closeall()Guillaume Nault
There are several ways to remove L2TP sessions: * deleting a session explicitly using the netlink interface (with L2TP_CMD_SESSION_DELETE), * deleting the session's parent tunnel (either by closing the tunnel's file descriptor or using the netlink interface), * closing the PPPOL2TP file descriptor of a PPP pseudo-wire. In some cases, when these methods are used concurrently on the same session, the session can be removed twice, leading to use-after-free bugs. This patch adds a 'dead' flag, used by l2tp_session_delete() and l2tp_tunnel_closeall() to prevent them from stepping on each other's toes. The session deletion path used when closing a PPPOL2TP file descriptor doesn't need to be adapted. It already has to ensure that a session remains valid for the lifetime of its PPPOL2TP file descriptor. So it takes an extra reference on the session in the ->session_close() callback (pppol2tp_session_close()), which is eventually dropped in the ->sk_destruct() callback of the PPPOL2TP socket (pppol2tp_session_destruct()). Still, __l2tp_session_unhash() and l2tp_session_queue_purge() can be called twice and even concurrently for a given session, but thanks to proper locking and re-initialisation of list fields, this is not an issue. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-25l2tp: ensure sessions are freed after their PPPOL2TP socketGuillaume Nault
If l2tp_tunnel_delete() or l2tp_tunnel_closeall() deletes a session right after pppol2tp_release() orphaned its socket, then the 'sock' variable of the pppol2tp_session_close() callback is NULL. Yet the session is still used by pppol2tp_release(). Therefore we need to take an extra reference in any case, to prevent l2tp_tunnel_delete() or l2tp_tunnel_closeall() from freeing the session. Since the pppol2tp_session_close() callback is only set if the session is associated to a PPPOL2TP socket and that both l2tp_tunnel_delete() and l2tp_tunnel_closeall() hold the PPPOL2TP socket before calling pppol2tp_session_close(), we're sure that pppol2tp_session_close() and pppol2tp_session_destruct() are paired and called in the right order. So the reference taken by the former will be released by the later. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-03l2tp: pass tunnel pointer to ->session_create()Guillaume Nault
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>
2017-09-03l2tp: prevent creation of sessions on terminated tunnelsGuillaume Nault
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>
2017-08-28l2tp: hold tunnel used while creating sessions with netlinkGuillaume Nault
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>
2017-08-28l2tp: hold tunnel while handling genl TUNNEL_GET commandsGuillaume Nault
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>
2017-08-28l2tp: hold tunnel while handling genl tunnel updatesGuillaume Nault
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>
2017-08-28l2tp: hold tunnel while processing genl delete commandGuillaume Nault
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>
2017-08-28l2tp: hold tunnel while looking up sessions in l2tp_netlinkGuillaume Nault
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. 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>
2017-08-28l2tp: initialise session's refcount before making it reachableGuillaume Nault
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. 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>
2017-07-04net, l2tp: convert l2tp_session.ref_count from atomic_t to refcount_tReshetova, Elena
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-04net, l2tp: convert l2tp_tunnel.ref_count from atomic_t to refcount_tReshetova, Elena
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01net: convert sock.sk_refcnt from atomic_t to refcount_tReshetova, Elena
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. This patch uses refcount_inc_not_zero() instead of atomic_inc_not_zero_hint() due to absense of a _hint() version of refcount API. If the hint() version must be used, we might need to revisit API. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-10l2tp: cast l2tp traffic counter to unsignedDominik Heidler
This fixes a counter problem on 32bit systems: When the rx_bytes counter reached 2 GiB, it jumpd to (2^64 Bytes - 2GiB) Bytes. rtnl_link_stats64 has __u64 type and atomic_long_read returns atomic_long_t which is signed. Due to the conversation we get an incorrect value on 32bit systems if the MSB of the atomic_long_t value is set. CC: Tom Parkin <tparkin@katalix.com> Fixes: 7b7c0719cd7a ("l2tp: avoid deadlock in l2tp stats update") Signed-off-by: Dominik Heidler <dheidler@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-07net: Fix inconsistent teardown and release of private netdev state.David S. Miller
Network devices can allocate reasources and private memory using netdev_ops->ndo_init(). However, the release of these resources can occur in one of two different places. Either netdev_ops->ndo_uninit() or netdev->destructor(). The decision of which operation frees the resources depends upon whether it is necessary for all netdev refs to be released before it is safe to perform the freeing. netdev_ops->ndo_uninit() presumably can occur right after the NETDEV_UNREGISTER notifier completes and the unicast and multicast address lists are flushed. netdev->destructor(), on the other hand, does not run until the netdev references all go away. Further complicating the situation is that netdev->destructor() almost universally does also a free_netdev(). This creates a problem for the logic in register_netdevice(). Because all callers of register_netdevice() manage the freeing of the netdev, and invoke free_netdev(dev) if register_netdevice() fails. If netdev_ops->ndo_init() succeeds, but something else fails inside of register_netdevice(), it does call ndo_ops->ndo_uninit(). But it is not able to invoke netdev->destructor(). This is because netdev->destructor() will do a free_netdev() and then the caller of register_netdevice() will do the same. However, this means that the resources that would normally be released by netdev->destructor() will not be. Over the years drivers have added local hacks to deal with this, by invoking their destructor parts by hand when register_netdevice() fails. Many drivers do not try to deal with this, and instead we have leaks. Let's close this hole by formalizing the distinction between what private things need to be freed up by netdev->destructor() and whether the driver needs unregister_netdevice() to perform the free_netdev(). netdev->priv_destructor() performs all actions to free up the private resources that used to be freed by netdev->destructor(), except for free_netdev(). netdev->needs_free_netdev is a boolean that indicates whether free_netdev() should be done at the end of unregister_netdevice(). Now, register_netdevice() can sanely release all resources after ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit() and netdev->priv_destructor(). And at the end of unregister_netdevice(), we invoke netdev->priv_destructor() and optionally call free_netdev(). Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-27l2tp: remove useless device duplication test in l2tp_eth_create()Guillaume Nault
There's no need to verify that cfg->ifname is unique at this point. register_netdev() will return -EEXIST if asked to create a device with a name that's alrealy in use. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-25l2tp: define "l2tpeth" device typeGuillaume Nault
Export type of l2tpeth interfaces to userspace (/sys/class/net/<iface>/uevent). Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Acked-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-25l2tp: set name_assign_type for devices created by l2tp_eth.cGuillaume Nault
Export naming scheme used when creating l2tpeth interfaces (/sys/class/net/<iface>/name_assign_type). This let userspace know if the device's name has been generated automatically or defined manually. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Acked-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-17l2tp: device MTU setup, tunnel socket needs a lockR. Parameswaran
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>
2017-04-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts were simply overlapping changes. In the net/ipv4/route.c case the code had simply moved around a little bit and the same fix was made in both 'net' and 'net-next'. In the net/sched/sch_generic.c case a fix in 'net' happened at the same time that a new argument was added to qdisc_hash_add(). Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-12l2tp: define parameters of l2tp_tunnel_find*() as "const"Guillaume Nault
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>
2017-04-12l2tp: define parameters of l2tp_session_get*() as "const"Guillaume Nault
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>
2017-04-11l2tp: remove l2tp_session_find()Guillaume Nault
This function isn't used anymore. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-11l2tp: remove useless duplicate session detection in l2tp_netlinkGuillaume Nault
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>
2017-04-08l2tp: don't mask errors in pppol2tp_getsockopt()Guillaume Nault
pppol2tp_getsockopt() doesn't take into account the error code returned by pppol2tp_tunnel_getsockopt() or pppol2tp_session_getsockopt(). If error occurs there, pppol2tp_getsockopt() continues unconditionally and reports erroneous values. 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>
2017-04-08l2tp: don't mask errors in pppol2tp_setsockopt()Guillaume Nault
pppol2tp_setsockopt() unconditionally overwrites the error value returned by pppol2tp_tunnel_setsockopt() or pppol2tp_session_setsockopt(), thus hiding errors from userspace. 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>
2017-04-06L2TP:Adjust intf MTU, add underlay L3, L2 hdrs.R. Parameswaran
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>
2017-04-04l2tp: fix PPP pseudo-wire auto-loadingGuillaume Nault
PPP pseudo-wire type is 7 (11 is L2TP_PWTYPE_IP). Fixes: f1f39f911027 ("l2tp: auto load type modules") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-04l2tp: take reference on sessions being dumpedGuillaume Nault
Take a reference on the sessions returned by l2tp_session_find_nth() (and rename it l2tp_session_get_nth() to reflect this change), so that caller is assured that the session isn't going to disappear while processing it. For procfs and debugfs handlers, the session is held in the .start() callback and dropped in .show(). Given that pppol2tp_seq_session_show() dereferences the associated PPPoL2TP socket and that l2tp_dfs_seq_session_show() might call pppol2tp_show(), we also need to call the session's .ref() callback to prevent the socket from going away from under us. Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Fixes: 0ad6614048cf ("l2tp: Add debugfs files for dumping l2tp debug info") 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>
2017-04-01l2tp: take a reference on sessions used in genetlink handlersGuillaume Nault
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>
2017-04-01l2tp: hold session while sending creation notificationsGuillaume Nault
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. 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>
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