BMC/Intel-BMC/linux.git/net/ipv4/tcp.c, branch dev-5.7

tcp: md5: allow changing MD5 keys in all socket states

2020-07-22T07:33:56+00:00

[ Upstream commit 1ca0fafd73c5268e8fc4b997094b8bb2bfe8deea ] This essentially reverts commit 721230326891 ("tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets") Mathieu reported that many vendors BGP implementations can actually switch TCP MD5 on established flows. Quoting Mathieu : Here is a list of a few network vendors along with their behavior with respect to TCP MD5: - Cisco: Allows for password to be changed, but within the hold-down timer (~180 seconds). - Juniper: When password is initially set on active connection it will reset, but after that any subsequent password changes no network resets. - Nokia: No notes on if they flap the tcp connection or not. - Ericsson/RedBack: Allows for 2 password (old/new) to co-exist until both sides are ok with new passwords. - Meta-Switch: Expects the password to be set before a connection is attempted, but no further info on whether they reset the TCP connection on a change. - Avaya: Disable the neighbor, then set password, then re-enable. - Zebos: Would normally allow the change when socket connected. We can revert my prior change because commit 9424e2e7ad93 ("tcp: md5: fix potential overestimation of TCP option space") removed the leak of 4 kernel bytes to the wire that was the main reason for my patch. While doing my investigations, I found a bug when a MD5 key is changed, leading to these commits that stable teams want to consider before backporting this revert : Commit 6a2febec338d ("tcp: md5: add missing memory barriers in tcp_md5_do_add()/tcp_md5_hash_key()") Commit e6ced831ef11 ("tcp: md5: refine tcp_md5_do_add()/tcp_md5_hash_key() barriers") Fixes: 721230326891 "tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets" Signed-off-by: Eric Dumazet Reported-by: Mathieu Desnoyers Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: md5: refine tcp_md5_do_add()/tcp_md5_hash_key() barriers

2020-07-22T07:33:56+00:00

[ Upstream commit e6ced831ef11a2a06e8d00aad9d4fc05b610bf38 ] My prior fix went a bit too far, according to Herbert and Mathieu. Since we accept that concurrent TCP MD5 lookups might see inconsistent keys, we can use READ_ONCE()/WRITE_ONCE() instead of smp_rmb()/smp_wmb() Clearing all key->key[] is needed to avoid possible KMSAN reports, if key->keylen is increased. Since tcp_md5_do_add() is not fast path, using __GFP_ZERO to clear all struct tcp_md5sig_key is simpler. data_race() was added in linux-5.8 and will prevent KCSAN reports, this can safely be removed in stable backports, if data_race() is not yet backported. v2: use data_race() both in tcp_md5_hash_key() and tcp_md5_do_add() Fixes: 6a2febec338d ("tcp: md5: add missing memory barriers in tcp_md5_do_add()/tcp_md5_hash_key()") Signed-off-by: Eric Dumazet Cc: Mathieu Desnoyers Cc: Herbert Xu Cc: Marco Elver Reviewed-by: Mathieu Desnoyers Acked-by: Herbert Xu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: md5: add missing memory barriers in tcp_md5_do_add()/tcp_md5_hash_key()

2020-07-22T07:33:56+00:00

[ Upstream commit 6a2febec338df7e7699a52d00b2e1207dcf65b28 ] MD5 keys are read with RCU protection, and tcp_md5_do_add() might update in-place a prior key. Normally, typical RCU updates would allocate a new piece of memory. In this case only key->key and key->keylen might be updated, and we do not care if an incoming packet could see the old key, the new one, or some intermediate value, since changing the key on a live flow is known to be problematic anyway. We only want to make sure that in the case key->keylen is changed, cpus in tcp_md5_hash_key() wont try to use uninitialized data, or crash because key->keylen was read twice to feed sg_init_one() and ahash_request_set_crypt() Fixes: 9ea88a153001 ("tcp: md5: check md5 signature without socket lock") Signed-off-by: Eric Dumazet Cc: Mathieu Desnoyers Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: make sure listeners don't initialize congestion-control state

2020-07-22T07:33:56+00:00

[ Upstream commit ce69e563b325f620863830c246a8698ccea52048 ] syzkaller found its way into setsockopt with TCP_CONGESTION "cdg". tcp_cdg_init() does a kcalloc to store the gradients. As sk_clone_lock just copies all the memory, the allocated pointer will be copied as well, if the app called setsockopt(..., TCP_CONGESTION) on the listener. If now the socket will be destroyed before the congestion-control has properly been initialized (through a call to tcp_init_transfer), we will end up freeing memory that does not belong to that particular socket, opening the door to a double-free: [ 11.413102] ================================================================== [ 11.414181] BUG: KASAN: double-free or invalid-free in tcp_cleanup_congestion_control+0x58/0xd0 [ 11.415329] [ 11.415560] CPU: 3 PID: 4884 Comm: syz-executor.5 Not tainted 5.8.0-rc2 #80 [ 11.416544] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 11.418148] Call Trace: [ 11.418534] [ 11.418834] dump_stack+0x7d/0xb0 [ 11.419297] print_address_description.constprop.0+0x1a/0x210 [ 11.422079] kasan_report_invalid_free+0x51/0x80 [ 11.423433] __kasan_slab_free+0x15e/0x170 [ 11.424761] kfree+0x8c/0x230 [ 11.425157] tcp_cleanup_congestion_control+0x58/0xd0 [ 11.425872] tcp_v4_destroy_sock+0x57/0x5a0 [ 11.426493] inet_csk_destroy_sock+0x153/0x2c0 [ 11.427093] tcp_v4_syn_recv_sock+0xb29/0x1100 [ 11.427731] tcp_get_cookie_sock+0xc3/0x4a0 [ 11.429457] cookie_v4_check+0x13d0/0x2500 [ 11.433189] tcp_v4_do_rcv+0x60e/0x780 [ 11.433727] tcp_v4_rcv+0x2869/0x2e10 [ 11.437143] ip_protocol_deliver_rcu+0x23/0x190 [ 11.437810] ip_local_deliver+0x294/0x350 [ 11.439566] __netif_receive_skb_one_core+0x15d/0x1a0 [ 11.441995] process_backlog+0x1b1/0x6b0 [ 11.443148] net_rx_action+0x37e/0xc40 [ 11.445361] __do_softirq+0x18c/0x61a [ 11.445881] asm_call_on_stack+0x12/0x20 [ 11.446409] [ 11.446716] do_softirq_own_stack+0x34/0x40 [ 11.447259] do_softirq.part.0+0x26/0x30 [ 11.447827] __local_bh_enable_ip+0x46/0x50 [ 11.448406] ip_finish_output2+0x60f/0x1bc0 [ 11.450109] __ip_queue_xmit+0x71c/0x1b60 [ 11.451861] __tcp_transmit_skb+0x1727/0x3bb0 [ 11.453789] tcp_rcv_state_process+0x3070/0x4d3a [ 11.456810] tcp_v4_do_rcv+0x2ad/0x780 [ 11.457995] __release_sock+0x14b/0x2c0 [ 11.458529] release_sock+0x4a/0x170 [ 11.459005] __inet_stream_connect+0x467/0xc80 [ 11.461435] inet_stream_connect+0x4e/0xa0 [ 11.462043] __sys_connect+0x204/0x270 [ 11.465515] __x64_sys_connect+0x6a/0xb0 [ 11.466088] do_syscall_64+0x3e/0x70 [ 11.466617] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 11.467341] RIP: 0033:0x7f56046dc469 [ 11.467844] Code: Bad RIP value. [ 11.468282] RSP: 002b:00007f5604dccdd8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a [ 11.469326] RAX: ffffffffffffffda RBX: 000000000068bf00 RCX: 00007f56046dc469 [ 11.470379] RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000004 [ 11.471311] RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000 [ 11.472286] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 11.473341] R13: 000000000041427c R14: 00007f5604dcd5c0 R15: 0000000000000003 [ 11.474321] [ 11.474527] Allocated by task 4884: [ 11.475031] save_stack+0x1b/0x40 [ 11.475548] __kasan_kmalloc.constprop.0+0xc2/0xd0 [ 11.476182] tcp_cdg_init+0xf0/0x150 [ 11.476744] tcp_init_congestion_control+0x9b/0x3a0 [ 11.477435] tcp_set_congestion_control+0x270/0x32f [ 11.478088] do_tcp_setsockopt.isra.0+0x521/0x1a00 [ 11.478744] __sys_setsockopt+0xff/0x1e0 [ 11.479259] __x64_sys_setsockopt+0xb5/0x150 [ 11.479895] do_syscall_64+0x3e/0x70 [ 11.480395] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 11.481097] [ 11.481321] Freed by task 4872: [ 11.481783] save_stack+0x1b/0x40 [ 11.482230] __kasan_slab_free+0x12c/0x170 [ 11.482839] kfree+0x8c/0x230 [ 11.483240] tcp_cleanup_congestion_control+0x58/0xd0 [ 11.483948] tcp_v4_destroy_sock+0x57/0x5a0 [ 11.484502] inet_csk_destroy_sock+0x153/0x2c0 [ 11.485144] tcp_close+0x932/0xfe0 [ 11.485642] inet_release+0xc1/0x1c0 [ 11.486131] __sock_release+0xc0/0x270 [ 11.486697] sock_close+0xc/0x10 [ 11.487145] __fput+0x277/0x780 [ 11.487632] task_work_run+0xeb/0x180 [ 11.488118] __prepare_exit_to_usermode+0x15a/0x160 [ 11.488834] do_syscall_64+0x4a/0x70 [ 11.489326] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Wei Wang fixed a part of these CDG-malloc issues with commit c12014440750 ("tcp: memset ca_priv data to 0 properly"). This patch here fixes the listener-scenario: We make sure that listeners setting the congestion-control through setsockopt won't initialize it (thus CDG never allocates on listeners). For those who use AF_UNSPEC to reuse a socket, tcp_disconnect() is changed to cleanup afterwards. (The issue can be reproduced at least down to v4.4.x.) Cc: Wei Wang Cc: Eric Dumazet Fixes: 2b0a8c9eee81 ("tcp: add CDG congestion control") Signed-off-by: Christoph Paasch Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: fix error recovery in tcp_zerocopy_receive()

2020-05-14T22:12:08+00:00

If user provides wrong virtual address in TCP_ZEROCOPY_RECEIVE operation we want to return -EINVAL error. But depending on zc->recv_skip_hint content, we might return -EIO error if the socket has SOCK_DONE set. Make sure to return -EINVAL in this case. BUG: KMSAN: uninit-value in tcp_zerocopy_receive net/ipv4/tcp.c:1833 [inline] BUG: KMSAN: uninit-value in do_tcp_getsockopt+0x4494/0x6320 net/ipv4/tcp.c:3685 CPU: 1 PID: 625 Comm: syz-executor.0 Not tainted 5.7.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 tcp_zerocopy_receive net/ipv4/tcp.c:1833 [inline] do_tcp_getsockopt+0x4494/0x6320 net/ipv4/tcp.c:3685 tcp_getsockopt+0xf8/0x1f0 net/ipv4/tcp.c:3728 sock_common_getsockopt+0x13f/0x180 net/core/sock.c:3131 __sys_getsockopt+0x533/0x7b0 net/socket.c:2177 __do_sys_getsockopt net/socket.c:2192 [inline] __se_sys_getsockopt+0xe1/0x100 net/socket.c:2189 __x64_sys_getsockopt+0x62/0x80 net/socket.c:2189 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1deeb72c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00000000004e01e0 RCX: 000000000045c829 RDX: 0000000000000023 RSI: 0000000000000006 RDI: 0000000000000009 RBP: 000000000078bf00 R08: 0000000020000200 R09: 0000000000000000 R10: 00000000200001c0 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000001d8 R14: 00000000004d3038 R15: 00007f1deeb736d4 Local variable ----zc@do_tcp_getsockopt created at: do_tcp_getsockopt+0x1a74/0x6320 net/ipv4/tcp.c:3670 do_tcp_getsockopt+0x1a74/0x6320 net/ipv4/tcp.c:3670 Fixes: 05255b823a61 ("tcp: add TCP_ZEROCOPY_RECEIVE support for zerocopy receive") Signed-off-by: Eric Dumazet Reported-by: syzbot Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller

tcp: fix SO_RCVLOWAT hangs with fat skbs

2020-05-12T19:49:47+00:00

We autotune rcvbuf whenever SO_RCVLOWAT is set to account for 100% overhead in tcp_set_rcvlowat() This works well when skb->len/skb->truesize ratio is bigger than 0.5 But if we receive packets with small MSS, we can end up in a situation where not enough bytes are available in the receive queue to satisfy RCVLOWAT setting. As our sk_rcvbuf limit is hit, we send zero windows in ACK packets, preventing remote peer from sending more data. Even autotuning does not help, because it only triggers at the time user process drains the queue. If no EPOLLIN is generated, this can not happen. Note poll() has a similar issue, after commit c7004482e8dc ("tcp: Respect SO_RCVLOWAT in tcp_poll().") Fixes: 03f45c883c6f ("tcp: avoid extra wakeups for SO_RCVLOWAT users") Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller

net: tcp: fix rx timestamp behavior for tcp_recvmsg

2020-05-08T23:09:22+00:00

The stated intent of the original commit is to is to "return the timestamp corresponding to the highest sequence number data returned." The current implementation returns the timestamp for the last byte of the last fully read skb, which is not necessarily the last byte in the recv buffer. This patch converts behavior to the original definition, and to the behavior of the previous draft versions of commit 98aaa913b4ed ("tcp: Extend SOF_TIMESTAMPING_RX_SOFTWARE to TCP recvmsg") which also match this behavior. Fixes: 98aaa913b4ed ("tcp: Extend SOF_TIMESTAMPING_RX_SOFTWARE to TCP recvmsg") Co-developed-by: Iris Liu Signed-off-by: Iris Liu Signed-off-by: Kelly Littlepage Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Acked-by: Willem de Bruijn Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-03-26T01:58:11+00:00

Overlapping header include additions in macsec.c A bug fix in 'net' overlapping with the removal of 'version' string in ena_netdev.c Overlapping test additions in selftests Makefile Overlapping PCI ID table adjustments in iwlwifi driver. Signed-off-by: David S. Miller

tcp: repair: fix TCP_QUEUE_SEQ implementation

2020-03-23T20:02:01+00:00

When application uses TCP_QUEUE_SEQ socket option to change tp->rcv_next, we must also update tp->copied_seq. Otherwise, stuff relying on tcp_inq() being precise can eventually be confused. For example, tcp_zerocopy_receive() might crash because it does not expect tcp_recv_skb() to return NULL. We could add tests in various places to fix the issue, or simply make sure tcp_inq() wont return a random value, and leave fast path as it is. Note that this fixes ioctl(fd, SIOCINQ, &val) at the same time. Fixes: ee9952831cfd ("tcp: Initial repair mode") Fixes: 05255b823a61 ("tcp: add TCP_ZEROCOPY_RECEIVE support for zerocopy receive") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller

inet: Use fallthrough;

2020-03-12T22:55:00+00:00

Convert the various uses of fallthrough comments to fallthrough; Done via script Link: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe@perches.com/ And by hand: net/ipv6/ip6_fib.c has a fallthrough comment outside of an #ifdef block that causes gcc to emit a warning if converted in-place. So move the new fallthrough; inside the containing #ifdef/#endif too. Signed-off-by: Joe Perches Signed-off-by: David S. Miller