linux-stable.git/net/ipv4, branch v5.17.7

net: igmp: respect RCU rules in ip_mc_source() and ip_mc_msfilter()

2022-05-12T10:32:35+00:00

commit dba5bdd57bea587ea4f0b79b03c71135f84a7e8b upstream.

syzbot reported an UAF in ip_mc_sf_allow() [1]

Whenever RCU protected list replaces an object,
the pointer to the new object needs to be updated
_before_ the call to kfree_rcu() or call_rcu()

Because kfree_rcu(ptr, rcu) got support for NULL ptr
only recently in commit 12edff045bc6 ("rcu: Make kfree_rcu()
ignore NULL pointers"), I chose to use the conditional
to make sure stable backports won't miss this detail.

if (psl)
    kfree_rcu(psl, rcu);

net/ipv6/mcast.c has similar issues, addressed in a separate patch.

[1]
BUG: KASAN: use-after-free in ip_mc_sf_allow+0x6bb/0x6d0 net/ipv4/igmp.c:2655
Read of size 4 at addr ffff88807d37b904 by task syz-executor.5/908

CPU: 0 PID: 908 Comm: syz-executor.5 Not tainted 5.18.0-rc4-syzkaller-00064-g8f4dd16603ce #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0xeb/0x467 mm/kasan/report.c:313
 print_report mm/kasan/report.c:429 [inline]
 kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491
 ip_mc_sf_allow+0x6bb/0x6d0 net/ipv4/igmp.c:2655
 raw_v4_input net/ipv4/raw.c:190 [inline]
 raw_local_deliver+0x4d1/0xbe0 net/ipv4/raw.c:218
 ip_protocol_deliver_rcu+0xcf/0xb30 net/ipv4/ip_input.c:193
 ip_local_deliver_finish+0x2ee/0x4c0 net/ipv4/ip_input.c:233
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip_local_deliver+0x1b3/0x200 net/ipv4/ip_input.c:254
 dst_input include/net/dst.h:461 [inline]
 ip_rcv_finish+0x1cb/0x2f0 net/ipv4/ip_input.c:437
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip_rcv+0xaa/0xd0 net/ipv4/ip_input.c:556
 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5405
 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5519
 netif_receive_skb_internal net/core/dev.c:5605 [inline]
 netif_receive_skb+0x13e/0x8e0 net/core/dev.c:5664
 tun_rx_batched.isra.0+0x460/0x720 drivers/net/tun.c:1534
 tun_get_user+0x28b7/0x3e30 drivers/net/tun.c:1985
 tun_chr_write_iter+0xdb/0x200 drivers/net/tun.c:2015
 call_write_iter include/linux/fs.h:2050 [inline]
 new_sync_write+0x38a/0x560 fs/read_write.c:504
 vfs_write+0x7c0/0xac0 fs/read_write.c:591
 ksys_write+0x127/0x250 fs/read_write.c:644
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f3f12c3bbff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 cc fd ff ff 48
RSP: 002b:00007f3f13ea9130 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f3f12d9bf60 RCX: 00007f3f12c3bbff
RDX: 0000000000000036 RSI: 0000000020002ac0 RDI: 00000000000000c8
RBP: 00007f3f12ce308d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000036 R11: 0000000000000293 R12: 0000000000000000
R13: 00007fffb68dd79f R14: 00007f3f13ea9300 R15: 0000000000022000
 

Allocated by task 908:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:436 [inline]
 ____kasan_kmalloc mm/kasan/common.c:515 [inline]
 ____kasan_kmalloc mm/kasan/common.c:474 [inline]
 __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:524
 kasan_kmalloc include/linux/kasan.h:234 [inline]
 __do_kmalloc mm/slab.c:3710 [inline]
 __kmalloc+0x209/0x4d0 mm/slab.c:3719
 kmalloc include/linux/slab.h:586 [inline]
 sock_kmalloc net/core/sock.c:2501 [inline]
 sock_kmalloc+0xb5/0x100 net/core/sock.c:2492
 ip_mc_source+0xba2/0x1100 net/ipv4/igmp.c:2392
 do_ip_setsockopt net/ipv4/ip_sockglue.c:1296 [inline]
 ip_setsockopt+0x2312/0x3ab0 net/ipv4/ip_sockglue.c:1432
 raw_setsockopt+0x274/0x2c0 net/ipv4/raw.c:861
 __sys_setsockopt+0x2db/0x6a0 net/socket.c:2180
 __do_sys_setsockopt net/socket.c:2191 [inline]
 __se_sys_setsockopt net/socket.c:2188 [inline]
 __x64_sys_setsockopt+0xba/0x150 net/socket.c:2188
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 753:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:45
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free+0x13d/0x180 mm/kasan/common.c:328
 kasan_slab_free include/linux/kasan.h:200 [inline]
 __cache_free mm/slab.c:3439 [inline]
 kmem_cache_free_bulk+0x69/0x460 mm/slab.c:3774
 kfree_bulk include/linux/slab.h:437 [inline]
 kfree_rcu_work+0x51c/0xa10 kernel/rcu/tree.c:3318
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Last potentially related work creation:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348
 kvfree_call_rcu+0x74/0x990 kernel/rcu/tree.c:3595
 ip_mc_msfilter+0x712/0xb60 net/ipv4/igmp.c:2510
 do_ip_setsockopt net/ipv4/ip_sockglue.c:1257 [inline]
 ip_setsockopt+0x32e1/0x3ab0 net/ipv4/ip_sockglue.c:1432
 raw_setsockopt+0x274/0x2c0 net/ipv4/raw.c:861
 __sys_setsockopt+0x2db/0x6a0 net/socket.c:2180
 __do_sys_setsockopt net/socket.c:2191 [inline]
 __se_sys_setsockopt net/socket.c:2188 [inline]
 __x64_sys_setsockopt+0xba/0x150 net/socket.c:2188
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Second to last potentially related work creation:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348
 call_rcu+0x99/0x790 kernel/rcu/tree.c:3074
 mpls_dev_notify+0x552/0x8a0 net/mpls/af_mpls.c:1656
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:84
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1938
 call_netdevice_notifiers_extack net/core/dev.c:1976 [inline]
 call_netdevice_notifiers net/core/dev.c:1990 [inline]
 unregister_netdevice_many+0x92e/0x1890 net/core/dev.c:10751
 default_device_exit_batch+0x449/0x590 net/core/dev.c:11245
 ops_exit_list+0x125/0x170 net/core/net_namespace.c:167
 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

The buggy address belongs to the object at ffff88807d37b900
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 4 bytes inside of
 64-byte region [ffff88807d37b900, ffff88807d37b940)

The buggy address belongs to the physical page:
page:ffffea0001f4dec0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807d37b180 pfn:0x7d37b
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffff888010c41340 ffffea0001c795c8 ffff888010c40200
raw: ffff88807d37b180 ffff88807d37b000 000000010000001f 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x342040(__GFP_IO|__GFP_NOWARN|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 2963, tgid 2963 (udevd), ts 139732238007, free_ts 139730893262
 prep_new_page mm/page_alloc.c:2441 [inline]
 get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408
 __alloc_pages_node include/linux/gfp.h:587 [inline]
 kmem_getpages mm/slab.c:1378 [inline]
 cache_grow_begin+0x75/0x350 mm/slab.c:2584
 cache_alloc_refill+0x27f/0x380 mm/slab.c:2957
 ____cache_alloc mm/slab.c:3040 [inline]
 ____cache_alloc mm/slab.c:3023 [inline]
 __do_cache_alloc mm/slab.c:3267 [inline]
 slab_alloc mm/slab.c:3309 [inline]
 __do_kmalloc mm/slab.c:3708 [inline]
 __kmalloc+0x3b3/0x4d0 mm/slab.c:3719
 kmalloc include/linux/slab.h:586 [inline]
 kzalloc include/linux/slab.h:714 [inline]
 tomoyo_encode2.part.0+0xe9/0x3a0 security/tomoyo/realpath.c:45
 tomoyo_encode2 security/tomoyo/realpath.c:31 [inline]
 tomoyo_encode+0x28/0x50 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x186/0x620 security/tomoyo/realpath.c:288
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822
 security_inode_getattr+0xcf/0x140 security/security.c:1350
 vfs_getattr fs/stat.c:157 [inline]
 vfs_statx+0x16a/0x390 fs/stat.c:232
 vfs_fstatat+0x8c/0xb0 fs/stat.c:255
 __do_sys_newfstatat+0x91/0x110 fs/stat.c:425
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1356 [inline]
 free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1406
 free_unref_page_prepare mm/page_alloc.c:3328 [inline]
 free_unref_page+0x19/0x6a0 mm/page_alloc.c:3423
 __vunmap+0x85d/0xd30 mm/vmalloc.c:2667
 __vfree+0x3c/0xd0 mm/vmalloc.c:2715
 vfree+0x5a/0x90 mm/vmalloc.c:2746
 __do_replace+0x16b/0x890 net/ipv6/netfilter/ip6_tables.c:1117
 do_replace net/ipv6/netfilter/ip6_tables.c:1157 [inline]
 do_ip6t_set_ctl+0x90d/0xb90 net/ipv6/netfilter/ip6_tables.c:1639
 nf_setsockopt+0x83/0xe0 net/netfilter/nf_sockopt.c:101
 ipv6_setsockopt+0x122/0x180 net/ipv6/ipv6_sockglue.c:1026
 tcp_setsockopt+0x136/0x2520 net/ipv4/tcp.c:3696
 __sys_setsockopt+0x2db/0x6a0 net/socket.c:2180
 __do_sys_setsockopt net/socket.c:2191 [inline]
 __se_sys_setsockopt net/socket.c:2188 [inline]
 __x64_sys_setsockopt+0xba/0x150 net/socket.c:2188
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Memory state around the buggy address:
 ffff88807d37b800: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
 ffff88807d37b880: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
>ffff88807d37b900: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff88807d37b980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88807d37ba00: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc

Fixes: c85bb41e9318 ("igmp: fix ip_mc_sf_allow race [v5]")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Cc: Flavio Leitner 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: fix F-RTO may not work correctly when receiving DSACK

2022-05-09T07:16:26+00:00

[ Upstream commit d9157f6806d1499e173770df1f1b234763de5c79 ]

Currently DSACK is regarded as a dupack, which may cause
F-RTO to incorrectly enter "loss was real" when receiving
DSACK.

Packetdrill to demonstrate:

// Enable F-RTO and TLP
    0 `sysctl -q net.ipv4.tcp_frto=2`
    0 `sysctl -q net.ipv4.tcp_early_retrans=3`
    0 `sysctl -q net.ipv4.tcp_congestion_control=cubic`

// Establish a connection
   +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
   +0 bind(3, ..., ...) = 0
   +0 listen(3, 1) = 0

// RTT 10ms, RTO 210ms
  +.1 < S 0:0(0) win 32792 
   +0 > S. 0:0(0) ack 1 <...>
 +.01 < . 1:1(0) ack 1 win 257
   +0 accept(3, ..., ...) = 4

// Send 2 data segments
   +0 write(4, ..., 2000) = 2000
   +0 > P. 1:2001(2000) ack 1

// TLP
+.022 > P. 1001:2001(1000) ack 1

// Continue to send 8 data segments
   +0 write(4, ..., 10000) = 10000
   +0 > P. 2001:10001(8000) ack 1

// RTO
+.188 > . 1:1001(1000) ack 1

// The original data is acked and new data is sent(F-RTO step 2.b)
   +0 < . 1:1(0) ack 2001 win 257
   +0 > P. 10001:12001(2000) ack 1

// D-SACK caused by TLP is regarded as a dupack, this results in
// the incorrect judgment of "loss was real"(F-RTO step 3.a)
+.022 < . 1:1(0) ack 2001 win 257 

// Never-retransmitted data(3001:4001) are acked and
// expect to switch to open state(F-RTO step 3.b)
   +0 < . 1:1(0) ack 4001 win 257
+0 %{ assert tcpi_ca_state == 0, tcpi_ca_state }%

Fixes: e33099f96d99 ("tcp: implement RFC5682 F-RTO")
Signed-off-by: Pengcheng Yang 
Acked-by: Neal Cardwell 
Tested-by: Neal Cardwell 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/1650967419-2150-1-git-send-email-yangpc@wangsu.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

tcp: make sure treq->af_specific is initialized

2022-05-09T07:16:23+00:00

[ Upstream commit ba5a4fdd63ae0c575707030db0b634b160baddd7 ]

syzbot complained about a recent change in TCP stack,
hitting a NULL pointer [1]

tcp request sockets have an af_specific pointer, which
was used before the blamed change only for SYNACK generation
in non SYNCOOKIE mode.

tcp requests sockets momentarily created when third packet
coming from client in SYNCOOKIE mode were not using
treq->af_specific.

Make sure this field is populated, in the same way normal
TCP requests sockets do in tcp_conn_request().

[1]
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies.  Check SNMP counters.
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 3695 Comm: syz-executor864 Not tainted 5.18.0-rc3-syzkaller-00224-g5fd1fe4807f9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tcp_create_openreq_child+0xe16/0x16b0 net/ipv4/tcp_minisocks.c:534
Code: 48 c1 ea 03 80 3c 02 00 0f 85 e5 07 00 00 4c 8b b3 28 01 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d 7e 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c9 07 00 00 48 8b 3c 24 48 89 de 41 ff 56 08 48
RSP: 0018:ffffc90000de0588 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888076490330 RCX: 0000000000000100
RDX: 0000000000000001 RSI: ffffffff87d67ff0 RDI: 0000000000000008
RBP: ffff88806ee1c7f8 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff87d67f00 R11: 0000000000000000 R12: ffff88806ee1bfc0
R13: ffff88801b0e0368 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f517fe58700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcead76960 CR3: 000000006f97b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 
 tcp_v6_syn_recv_sock+0x199/0x23b0 net/ipv6/tcp_ipv6.c:1267
 tcp_get_cookie_sock+0xc9/0x850 net/ipv4/syncookies.c:207
 cookie_v6_check+0x15c3/0x2340 net/ipv6/syncookies.c:258
 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1131 [inline]
 tcp_v6_do_rcv+0x1148/0x13b0 net/ipv6/tcp_ipv6.c:1486
 tcp_v6_rcv+0x3305/0x3840 net/ipv6/tcp_ipv6.c:1725
 ip6_protocol_deliver_rcu+0x2e9/0x1900 net/ipv6/ip6_input.c:422
 ip6_input_finish+0x14c/0x2c0 net/ipv6/ip6_input.c:464
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:473
 dst_input include/net/dst.h:461 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ipv6_rcv+0x27f/0x3b0 net/ipv6/ip6_input.c:297
 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5405
 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5519
 process_backlog+0x3a0/0x7c0 net/core/dev.c:5847
 __napi_poll+0xb3/0x6e0 net/core/dev.c:6413
 napi_poll net/core/dev.c:6480 [inline]
 net_rx_action+0x8ec/0xc60 net/core/dev.c:6567
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097

Fixes: 5b0b9e4c2c89 ("tcp: md5: incorrect tcp_header_len for incoming connections")
Signed-off-by: Eric Dumazet 
Cc: Francesco Ruggeri 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

tcp: fix potential xmit stalls caused by TCP_NOTSENT_LOWAT

2022-05-09T07:16:23+00:00

[ Upstream commit 4bfe744ff1644fbc0a991a2677dc874475dd6776 ]

I had this bug sitting for too long in my pile, it is time to fix it.

Thanks to Doug Porter for reminding me of it!

We had various attempts in the past, including commit
0cbe6a8f089e ("tcp: remove SOCK_QUEUE_SHRUNK"),
but the issue is that TCP stack currently only generates
EPOLLOUT from input path, when tp->snd_una has advanced
and skb(s) cleaned from rtx queue.

If a flow has a big RTT, and/or receives SACKs, it is possible
that the notsent part (tp->write_seq - tp->snd_nxt) reaches 0
and no more data can be sent until tp->snd_una finally advances.

What is needed is to also check if POLLOUT needs to be generated
whenever tp->snd_nxt is advanced, from output path.

This bug triggers more often after an idle period, as
we do not receive ACK for at least one RTT. tcp_notsent_lowat
could be a fraction of what CWND and pacing rate would allow to
send during this RTT.

In a followup patch, I will remove the bogus call
to tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED)
from tcp_check_space(). Fact that we have decided to generate
an EPOLLOUT does not mean the application has immediately
refilled the transmit queue. This optimistic call
might have been the reason the bug seemed not too serious.

Tested:

200 ms rtt, 1% packet loss, 32 MB tcp_rmem[2] and tcp_wmem[2]

$ echo 500000 >/proc/sys/net/ipv4/tcp_notsent_lowat
$ cat bench_rr.sh
SUM=0
for i in {1..10}
do
 V=`netperf -H remote_host -l30 -t TCP_RR -- -r 10000000,10000 -o LOCAL_BYTES_SENT | egrep -v "MIGRATED|Bytes"`
 echo $V
 SUM=$(($SUM + $V))
done
echo SUM=$SUM

Before patch:
$ bench_rr.sh
130000000
80000000
140000000
140000000
140000000
140000000
130000000
40000000
90000000
110000000
SUM=1140000000

After patch:
$ bench_rr.sh
430000000
590000000
530000000
450000000
450000000
350000000
450000000
490000000
480000000
460000000
SUM=4680000000  # This is 410 % of the value before patch.

Fixes: c9bee3b7fdec ("tcp: TCP_NOTSENT_LOWAT socket option")
Signed-off-by: Eric Dumazet 
Reported-by: Doug Porter 
Cc: Soheil Hassas Yeganeh 
Cc: Neal Cardwell 
Acked-by: Soheil Hassas Yeganeh 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ip_gre, ip6_gre: Fix race condition on o_seqno in collect_md mode

2022-05-09T07:16:23+00:00

[ Upstream commit 31c417c948d7f6909cb63f0ac3298f3c38f8ce20 ]

As pointed out by Jakub Kicinski, currently using TUNNEL_SEQ in
collect_md mode is racy for [IP6]GRE[TAP] devices.  Consider the
following sequence of events:

1. An [IP6]GRE[TAP] device is created in collect_md mode using "ip link
   add ... external".  "ip" ignores "[o]seq" if "external" is specified,
   so TUNNEL_SEQ is off, and the device is marked as NETIF_F_LLTX (i.e.
   it uses lockless TX);
2. Someone sets TUNNEL_SEQ on outgoing skb's, using e.g.
   bpf_skb_set_tunnel_key() in an eBPF program attached to this device;
3. gre_fb_xmit() or __gre6_xmit() processes these skb's:

	gre_build_header(skb, tun_hlen,
			 flags, protocol,
			 tunnel_id_to_key32(tun_info->key.tun_id),
			 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
					      : 0);   ^^^^^^^^^^^^^^^^^

Since we are not using the TX lock (&txq->_xmit_lock), multiple CPUs may
try to do this tunnel->o_seqno++ in parallel, which is racy.  Fix it by
making o_seqno atomic_t.

As mentioned by Eric Dumazet in commit b790e01aee74 ("ip_gre: lockless
xmit"), making o_seqno atomic_t increases "chance for packets being out
of order at receiver" when NETIF_F_LLTX is on.

Maybe a better fix would be:

1. Do not ignore "oseq" in external mode.  Users MUST specify "oseq" if
   they want the kernel to allow sequencing of outgoing packets;
2. Reject all outgoing TUNNEL_SEQ packets if the device was not created
   with "oseq".

Unfortunately, that would break userspace.

We could now make [IP6]GRE[TAP] devices always NETIF_F_LLTX, but let us
do it in separate patches to keep this fix minimal.

Suggested-by: Jakub Kicinski 
Fixes: 77a5196a804e ("gre: add sequence number for collect md mode.")
Signed-off-by: Peilin Ye 
Acked-by: William Tu 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ip_gre: Make o_seqno start from 0 in native mode

2022-05-09T07:16:23+00:00

[ Upstream commit ff827beb706ed719c766acf36449801ded0c17fc ]

For GRE and GRETAP devices, currently o_seqno starts from 1 in native
mode.  According to RFC 2890 2.2., "The first datagram is sent with a
sequence number of 0."  Fix it.

It is worth mentioning that o_seqno already starts from 0 in collect_md
mode, see gre_fb_xmit(), where tunnel->o_seqno is passed to
gre_build_header() before getting incremented.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Peilin Ye 
Acked-by: William Tu 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

tcp: ensure to use the most recently sent skb when filling the rate sample

2022-05-09T07:16:21+00:00

[ Upstream commit b253a0680ceadc5d7b4acca7aa2d870326cad8ad ]

If an ACK (s)acks multiple skbs, we favor the information
from the most recently sent skb by choosing the skb with
the highest prior_delivered count. But in the interval
between receiving ACKs, we send multiple skbs with the same
prior_delivered, because the tp->delivered only changes
when we receive an ACK.

We used RACK's solution, copying tcp_rack_sent_after() as
tcp_skb_sent_after() helper to determine "which packet was
sent last?". Later, we will use tcp_skb_sent_after() instead
in RACK.

Fixes: b9f64820fb22 ("tcp: track data delivery rate for a TCP connection")
Signed-off-by: Pengcheng Yang 
Cc: Paolo Abeni 
Acked-by: Neal Cardwell 
Tested-by: Neal Cardwell 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/1650422081-22153-1-git-send-email-yangpc@wangsu.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

tcp: md5: incorrect tcp_header_len for incoming connections

2022-05-09T07:16:21+00:00

[ Upstream commit 5b0b9e4c2c895227c8852488b3f09839233bba54 ]

In tcp_create_openreq_child we adjust tcp_header_len for md5 using the
remote address in newsk. But that address is still 0 in newsk at this
point, and it is only set later by the callers (tcp_v[46]_syn_recv_sock).
Use the address from the request socket instead.

Fixes: cfb6eeb4c860 ("[TCP]: MD5 Signature Option (RFC2385) support.")
Signed-off-by: Francesco Ruggeri 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20220421005026.686A45EC01F2@us226.sjc.aristanetworks.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

esp: limit skb_page_frag_refill use to a single page

2022-04-27T12:40:58+00:00

[ Upstream commit 5bd8baab087dff657e05387aee802e70304cc813 ]

Commit ebe48d368e97 ("esp: Fix possible buffer overflow in ESP
transformation") tried to fix skb_page_frag_refill usage in ESP by
capping allocsize to 32k, but that doesn't completely solve the issue,
as skb_page_frag_refill may return a single page. If that happens, we
will write out of bounds, despite the check introduced in the previous
patch.

This patch forces COW in cases where we would end up calling
skb_page_frag_refill with a size larger than a page (first in
esp_output_head with tailen, then in esp_output_tail with
skb->data_len).

Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible")
Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible")
Signed-off-by: Sabrina Dubroca 
Signed-off-by: Steffen Klassert 
Signed-off-by: Sasha Levin

net: ipv4: fix route with nexthop object delete warning

2022-04-13T17:27:29+00:00

[ Upstream commit 6bf92d70e690b7ff12b24f4bfff5e5434d019b82 ]

FRR folks have hit a kernel warning[1] while deleting routes[2] which is
caused by trying to delete a route pointing to a nexthop id without
specifying nhid but matching on an interface. That is, a route is found
but we hit a warning while matching it. The warning is from
fib_info_nh() in include/net/nexthop.h because we run it on a fib_info
with nexthop object. The call chain is:
 inet_rtm_delroute -> fib_table_delete -> fib_nh_match (called with a
nexthop fib_info and also with fc_oif set thus calling fib_info_nh on
the fib_info and triggering the warning). The fix is to not do any
matching in that branch if the fi has a nexthop object because those are
managed separately. I.e. we should match when deleting without nh spec and
should fail when deleting a nexthop route with old-style nh spec because
nexthop objects are managed separately, e.g.:
 $ ip r show 1.2.3.4/32
 1.2.3.4 nhid 12 via 192.168.11.2 dev dummy0

 $ ip r del 1.2.3.4/32
 $ ip r del 1.2.3.4/32 nhid 12
 

 $ ip r del 1.2.3.4/32 dev dummy0
 

[1]
 [  523.462226] ------------[ cut here ]------------
 [  523.462230] WARNING: CPU: 14 PID: 22893 at include/net/nexthop.h:468 fib_nh_match+0x210/0x460
 [  523.462236] Modules linked in: dummy rpcsec_gss_krb5 xt_socket nf_socket_ipv4 nf_socket_ipv6 ip6table_raw iptable_raw bpf_preload xt_statistic ip_set ip_vs_sh ip_vs_wrr ip_vs_rr ip_vs xt_mark nf_tables xt_nat veth nf_conntrack_netlink nfnetlink xt_addrtype br_netfilter overlay dm_crypt nfsv3 nfs fscache netfs vhost_net vhost vhost_iotlb tap tun xt_CHECKSUM xt_MASQUERADE xt_conntrack 8021q garp mrp ipt_REJECT nf_reject_ipv4 ip6table_mangle ip6table_nat iptable_mangle iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bridge stp llc rfcomm snd_seq_dummy snd_hrtimer rpcrdma rdma_cm iw_cm ib_cm ib_core ip6table_filter xt_comment ip6_tables vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) qrtr bnep binfmt_misc xfs vfat fat squashfs loop nvidia_drm(POE) nvidia_modeset(POE) nvidia_uvm(POE) nvidia(POE) intel_rapl_msr intel_rapl_common snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio snd_hda_codec_hdmi btusb btrtl iwlmvm uvcvideo btbcm snd_hda_intel edac_mce_amd
 [  523.462274]  videobuf2_vmalloc videobuf2_memops btintel snd_intel_dspcfg videobuf2_v4l2 snd_intel_sdw_acpi bluetooth snd_usb_audio snd_hda_codec mac80211 snd_usbmidi_lib joydev snd_hda_core videobuf2_common kvm_amd snd_rawmidi snd_hwdep snd_seq videodev ccp snd_seq_device libarc4 ecdh_generic mc snd_pcm kvm iwlwifi snd_timer drm_kms_helper snd cfg80211 cec soundcore irqbypass rapl wmi_bmof i2c_piix4 rfkill k10temp pcspkr acpi_cpufreq nfsd auth_rpcgss nfs_acl lockd grace sunrpc drm zram ip_tables crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel nvme sp5100_tco r8169 nvme_core wmi ipmi_devintf ipmi_msghandler fuse
 [  523.462300] CPU: 14 PID: 22893 Comm: ip Tainted: P           OE     5.16.18-200.fc35.x86_64 #1
 [  523.462302] Hardware name: Micro-Star International Co., Ltd. MS-7C37/MPG X570 GAMING EDGE WIFI (MS-7C37), BIOS 1.C0 10/29/2020
 [  523.462303] RIP: 0010:fib_nh_match+0x210/0x460
 [  523.462304] Code: 7c 24 20 48 8b b5 90 00 00 00 e8 bb ee f4 ff 48 8b 7c 24 20 41 89 c4 e8 ee eb f4 ff 45 85 e4 0f 85 2e fe ff ff e9 4c ff ff ff <0f> 0b e9 17 ff ff ff 3c 0a 0f 85 61 fe ff ff 48 8b b5 98 00 00 00
 [  523.462306] RSP: 0018:ffffaa53d4d87928 EFLAGS: 00010286
 [  523.462307] RAX: 0000000000000000 RBX: ffffaa53d4d87a90 RCX: ffffaa53d4d87bb0
 [  523.462308] RDX: ffff9e3d2ee6be80 RSI: ffffaa53d4d87a90 RDI: ffffffff920ed380
 [  523.462309] RBP: ffff9e3d2ee6be80 R08: 0000000000000064 R09: 0000000000000000
 [  523.462310] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000031
 [  523.462310] R13: 0000000000000020 R14: 0000000000000000 R15: ffff9e3d331054e0
 [  523.462311] FS:  00007f245517c1c0(0000) GS:ffff9e492ed80000(0000) knlGS:0000000000000000
 [  523.462313] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [  523.462313] CR2: 000055e5dfdd8268 CR3: 00000003ef488000 CR4: 0000000000350ee0
 [  523.462315] Call Trace:
 [  523.462316]  
 [  523.462320]  fib_table_delete+0x1a9/0x310
 [  523.462323]  inet_rtm_delroute+0x93/0x110
 [  523.462325]  rtnetlink_rcv_msg+0x133/0x370
 [  523.462327]  ? _copy_to_iter+0xb5/0x6f0
 [  523.462330]  ? rtnl_calcit.isra.0+0x110/0x110
 [  523.462331]  netlink_rcv_skb+0x50/0xf0
 [  523.462334]  netlink_unicast+0x211/0x330
 [  523.462336]  netlink_sendmsg+0x23f/0x480
 [  523.462338]  sock_sendmsg+0x5e/0x60
 [  523.462340]  ____sys_sendmsg+0x22c/0x270
 [  523.462341]  ? import_iovec+0x17/0x20
 [  523.462343]  ? sendmsg_copy_msghdr+0x59/0x90
 [  523.462344]  ? __mod_lruvec_page_state+0x85/0x110
 [  523.462348]  ___sys_sendmsg+0x81/0xc0
 [  523.462350]  ? netlink_seq_start+0x70/0x70
 [  523.462352]  ? __dentry_kill+0x13a/0x180
 [  523.462354]  ? __fput+0xff/0x250
 [  523.462356]  __sys_sendmsg+0x49/0x80
 [  523.462358]  do_syscall_64+0x3b/0x90
 [  523.462361]  entry_SYSCALL_64_after_hwframe+0x44/0xae
 [  523.462364] RIP: 0033:0x7f24552aa337
 [  523.462365] Code: 0e 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
 [  523.462366] RSP: 002b:00007fff7f05a838 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
 [  523.462368] RAX: ffffffffffffffda RBX: 000000006245bf91 RCX: 00007f24552aa337
 [  523.462368] RDX: 0000000000000000 RSI: 00007fff7f05a8a0 RDI: 0000000000000003
 [  523.462369] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
 [  523.462370] R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000001
 [  523.462370] R13: 00007fff7f05ce08 R14: 0000000000000000 R15: 000055e5dfdd1040
 [  523.462373]  
 [  523.462374] ---[ end trace ba537bc16f6bf4ed ]---

[2] https://github.com/FRRouting/frr/issues/6412

Fixes: 4c7e8084fd46 ("ipv4: Plumb support for nexthop object in a fib_info")
Signed-off-by: Nikolay Aleksandrov 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin