Fork of alistair23 Linux kernel for reMarkable from https://github.com/alistair23/linux
Go to file
Petr Machata 5691484df9 net: ip6_gre: Fix headroom request in ip6erspan_tunnel_xmit()
dev->needed_headroom is not primed until ip6_tnl_xmit(), so it starts
out zero. Thus the call to skb_cow_head() fails to actually make sure
there's enough headroom to push the ERSPAN headers to. That can lead to
the panic cited below. (Reproducer below that).

Fix by requesting either needed_headroom if already primed, or just the
bare minimum needed for the header otherwise.

[  190.703567] kernel BUG at net/core/skbuff.c:104!
[  190.708384] invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
[  190.714007] Modules linked in: act_mirred cls_matchall ip6_gre ip6_tunnel tunnel6 gre sch_ingress vrf veth x86_pkg_temp_thermal mlx_platform nfsd e1000e leds_mlxcpld
[  190.728975] CPU: 1 PID: 959 Comm: kworker/1:2 Not tainted 4.17.0-rc4-net_master-custom-139 #10
[  190.737647] Hardware name: Mellanox Technologies Ltd. "MSN2410-CB2F"/"SA000874", BIOS 4.6.5 03/08/2016
[  190.747006] Workqueue: ipv6_addrconf addrconf_dad_work
[  190.752222] RIP: 0010:skb_panic+0xc3/0x100
[  190.756358] RSP: 0018:ffff8801d54072f0 EFLAGS: 00010282
[  190.761629] RAX: 0000000000000085 RBX: ffff8801c1a8ecc0 RCX: 0000000000000000
[  190.768830] RDX: 0000000000000085 RSI: dffffc0000000000 RDI: ffffed003aa80e54
[  190.776025] RBP: ffff8801bd1ec5a0 R08: ffffed003aabce19 R09: ffffed003aabce19
[  190.783226] R10: 0000000000000001 R11: ffffed003aabce18 R12: ffff8801bf695dbe
[  190.790418] R13: 0000000000000084 R14: 00000000000006c0 R15: ffff8801bf695dc8
[  190.797621] FS:  0000000000000000(0000) GS:ffff8801d5400000(0000) knlGS:0000000000000000
[  190.805786] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  190.811582] CR2: 000055fa929aced0 CR3: 0000000003228004 CR4: 00000000001606e0
[  190.818790] Call Trace:
[  190.821264]  <IRQ>
[  190.823314]  ? ip6erspan_tunnel_xmit+0x5e4/0x1982 [ip6_gre]
[  190.828940]  ? ip6erspan_tunnel_xmit+0x5e4/0x1982 [ip6_gre]
[  190.834562]  skb_push+0x78/0x90
[  190.837749]  ip6erspan_tunnel_xmit+0x5e4/0x1982 [ip6_gre]
[  190.843219]  ? ip6gre_tunnel_ioctl+0xd90/0xd90 [ip6_gre]
[  190.848577]  ? debug_check_no_locks_freed+0x210/0x210
[  190.853679]  ? debug_check_no_locks_freed+0x210/0x210
[  190.858783]  ? print_irqtrace_events+0x120/0x120
[  190.863451]  ? sched_clock_cpu+0x18/0x210
[  190.867496]  ? cyc2ns_read_end+0x10/0x10
[  190.871474]  ? skb_network_protocol+0x76/0x200
[  190.875977]  dev_hard_start_xmit+0x137/0x770
[  190.880317]  ? do_raw_spin_trylock+0x6d/0xa0
[  190.884624]  sch_direct_xmit+0x2ef/0x5d0
[  190.888589]  ? pfifo_fast_dequeue+0x3fa/0x670
[  190.892994]  ? pfifo_fast_change_tx_queue_len+0x810/0x810
[  190.898455]  ? __lock_is_held+0xa0/0x160
[  190.902422]  __qdisc_run+0x39e/0xfc0
[  190.906041]  ? _raw_spin_unlock+0x29/0x40
[  190.910090]  ? pfifo_fast_enqueue+0x24b/0x3e0
[  190.914501]  ? sch_direct_xmit+0x5d0/0x5d0
[  190.918658]  ? pfifo_fast_dequeue+0x670/0x670
[  190.923047]  ? __dev_queue_xmit+0x172/0x1770
[  190.927365]  ? preempt_count_sub+0xf/0xd0
[  190.931421]  __dev_queue_xmit+0x410/0x1770
[  190.935553]  ? ___slab_alloc+0x605/0x930
[  190.939524]  ? print_irqtrace_events+0x120/0x120
[  190.944186]  ? memcpy+0x34/0x50
[  190.947364]  ? netdev_pick_tx+0x1c0/0x1c0
[  190.951428]  ? __skb_clone+0x2fd/0x3d0
[  190.955218]  ? __copy_skb_header+0x270/0x270
[  190.959537]  ? rcu_read_lock_sched_held+0x93/0xa0
[  190.964282]  ? kmem_cache_alloc+0x344/0x4d0
[  190.968520]  ? cyc2ns_read_end+0x10/0x10
[  190.972495]  ? skb_clone+0x123/0x230
[  190.976112]  ? skb_split+0x820/0x820
[  190.979747]  ? tcf_mirred+0x554/0x930 [act_mirred]
[  190.984582]  tcf_mirred+0x554/0x930 [act_mirred]
[  190.989252]  ? tcf_mirred_act_wants_ingress.part.2+0x10/0x10 [act_mirred]
[  190.996109]  ? __lock_acquire+0x706/0x26e0
[  191.000239]  ? sched_clock_cpu+0x18/0x210
[  191.004294]  tcf_action_exec+0xcf/0x2a0
[  191.008179]  tcf_classify+0xfa/0x340
[  191.011794]  __netif_receive_skb_core+0x8e1/0x1c60
[  191.016630]  ? debug_check_no_locks_freed+0x210/0x210
[  191.021732]  ? nf_ingress+0x500/0x500
[  191.025458]  ? process_backlog+0x347/0x4b0
[  191.029619]  ? print_irqtrace_events+0x120/0x120
[  191.034302]  ? lock_acquire+0xd8/0x320
[  191.038089]  ? process_backlog+0x1b6/0x4b0
[  191.042246]  ? process_backlog+0xc2/0x4b0
[  191.046303]  process_backlog+0xc2/0x4b0
[  191.050189]  net_rx_action+0x5cc/0x980
[  191.053991]  ? napi_complete_done+0x2c0/0x2c0
[  191.058386]  ? mark_lock+0x13d/0xb40
[  191.062001]  ? clockevents_program_event+0x6b/0x1d0
[  191.066922]  ? print_irqtrace_events+0x120/0x120
[  191.071593]  ? __lock_is_held+0xa0/0x160
[  191.075566]  __do_softirq+0x1d4/0x9d2
[  191.079282]  ? ip6_finish_output2+0x524/0x1460
[  191.083771]  do_softirq_own_stack+0x2a/0x40
[  191.087994]  </IRQ>
[  191.090130]  do_softirq.part.13+0x38/0x40
[  191.094178]  __local_bh_enable_ip+0x135/0x190
[  191.098591]  ip6_finish_output2+0x54d/0x1460
[  191.102916]  ? ip6_forward_finish+0x2f0/0x2f0
[  191.107314]  ? ip6_mtu+0x3c/0x2c0
[  191.110674]  ? ip6_finish_output+0x2f8/0x650
[  191.114992]  ? ip6_output+0x12a/0x500
[  191.118696]  ip6_output+0x12a/0x500
[  191.122223]  ? ip6_route_dev_notify+0x5b0/0x5b0
[  191.126807]  ? ip6_finish_output+0x650/0x650
[  191.131120]  ? ip6_fragment+0x1a60/0x1a60
[  191.135182]  ? icmp6_dst_alloc+0x26e/0x470
[  191.139317]  mld_sendpack+0x672/0x830
[  191.143021]  ? igmp6_mcf_seq_next+0x2f0/0x2f0
[  191.147429]  ? __local_bh_enable_ip+0x77/0x190
[  191.151913]  ipv6_mc_dad_complete+0x47/0x90
[  191.156144]  addrconf_dad_completed+0x561/0x720
[  191.160731]  ? addrconf_rs_timer+0x3a0/0x3a0
[  191.165036]  ? mark_held_locks+0xc9/0x140
[  191.169095]  ? __local_bh_enable_ip+0x77/0x190
[  191.173570]  ? addrconf_dad_work+0x50d/0xa20
[  191.177886]  ? addrconf_dad_work+0x529/0xa20
[  191.182194]  addrconf_dad_work+0x529/0xa20
[  191.186342]  ? addrconf_dad_completed+0x720/0x720
[  191.191088]  ? __lock_is_held+0xa0/0x160
[  191.195059]  ? process_one_work+0x45d/0xe20
[  191.199302]  ? process_one_work+0x51e/0xe20
[  191.203531]  ? rcu_read_lock_sched_held+0x93/0xa0
[  191.208279]  process_one_work+0x51e/0xe20
[  191.212340]  ? pwq_dec_nr_in_flight+0x200/0x200
[  191.216912]  ? get_lock_stats+0x4b/0xf0
[  191.220788]  ? preempt_count_sub+0xf/0xd0
[  191.224844]  ? worker_thread+0x219/0x860
[  191.228823]  ? do_raw_spin_trylock+0x6d/0xa0
[  191.233142]  worker_thread+0xeb/0x860
[  191.236848]  ? process_one_work+0xe20/0xe20
[  191.241095]  kthread+0x206/0x300
[  191.244352]  ? process_one_work+0xe20/0xe20
[  191.248587]  ? kthread_stop+0x570/0x570
[  191.252459]  ret_from_fork+0x3a/0x50
[  191.256082] Code: 14 3e ff 8b 4b 78 55 4d 89 f9 41 56 41 55 48 c7 c7 a0 cf db 82 41 54 44 8b 44 24 2c 48 8b 54 24 30 48 8b 74 24 20 e8 16 94 13 ff <0f> 0b 48 c7 c7 60 8e 1f 85 48 83 c4 20 e8 55 ef a6 ff 89 74 24
[  191.275327] RIP: skb_panic+0xc3/0x100 RSP: ffff8801d54072f0
[  191.281024] ---[ end trace 7ea51094e099e006 ]---
[  191.285724] Kernel panic - not syncing: Fatal exception in interrupt
[  191.292168] Kernel Offset: disabled
[  191.295697] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

Reproducer:

	ip link add h1 type veth peer name swp1
	ip link add h3 type veth peer name swp3

	ip link set dev h1 up
	ip address add 192.0.2.1/28 dev h1

	ip link add dev vh3 type vrf table 20
	ip link set dev h3 master vh3
	ip link set dev vh3 up
	ip link set dev h3 up

	ip link set dev swp3 up
	ip address add dev swp3 2001:db8:2::1/64

	ip link set dev swp1 up
	tc qdisc add dev swp1 clsact

	ip link add name gt6 type ip6erspan \
		local 2001:db8:2::1 remote 2001:db8:2::2 oseq okey 123
	ip link set dev gt6 up

	sleep 1

	tc filter add dev swp1 ingress pref 1000 matchall skip_hw \
		action mirred egress mirror dev gt6
	ping -I h1 192.0.2.2

Fixes: e41c7c68ea ("ip6erspan: make sure enough headroom at xmit.")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-17 16:50:06 -04:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-05-11 14:14:46 -07:00
block blk-mq: fix sysfs inflight counter 2018-04-26 09:02:01 -06:00
certs certs/blacklist_nohashes.c: fix const confusion in certs blacklist 2018-02-21 15:35:43 -08:00
crypto crypto: drbg - set freed buffers to NULL 2018-04-21 00:57:00 +08:00
Documentation net: phy: micrel: add 125MHz reference clock workaround 2018-05-16 12:20:03 -04:00
drivers ibmvnic: Fix statistics buffers memory leak 2018-05-17 14:57:19 -04:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs ceph: fix iov_iter issues in ceph_direct_read_write() 2018-05-10 10:15:12 +02:00
include tls: don't use stack memory in a scatterlist 2018-05-17 14:49:38 -04:00
init Fix typo in comment. 2018-05-07 05:41:46 -10:00
ipc ipc/shm: fix use-after-free of shm file via remap_file_pages() 2018-04-13 17:10:27 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-05-11 14:14:46 -07:00
lib swiotlb: fix inversed DMA_ATTR_NO_WARN test 2018-05-02 14:48:55 +02:00
LICENSES LICENSES: Add MPL-1.1 license 2018-01-06 10:59:44 -07:00
mm mmap: introduce sane default mmap limits 2018-05-11 09:52:01 -07:00
net net: ip6_gre: Fix headroom request in ip6erspan_tunnel_xmit() 2018-05-17 16:50:06 -04:00
samples bpf: sockmap sample use clang flag, -target bpf 2018-04-23 23:42:21 +02:00
scripts DeviceTree fixes for 4.17: 2018-05-07 05:33:29 -10:00
security Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-04-24 17:58:51 -07:00
sound ALSA: pcm: Check PCM state at xfern compat ioctl 2018-05-02 08:54:54 +02:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2018-05-13 21:07:02 -04:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt KVM/arm fixes for 4.17, take #2 2018-05-05 23:05:31 +02:00
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap Merge candidates for 4.17 merge window 2018-04-06 17:35:43 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-05-11 14:14:46 -07:00
Makefile Linux 4.17-rc4 2018-05-06 16:57:38 -10:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.