Go to file
Vinicius Costa Gomes b09fe70ef5 taprio: Fix sending packets without dequeueing them
There was a bug that was causing packets to be sent to the driver
without first calling dequeue() on the "child" qdisc. And the KASAN
report below shows that sending a packet without calling dequeue()
leads to bad results.

The problem is that when checking the last qdisc "child" we do not set
the returned skb to NULL, which can cause it to be sent to the driver,
and so after the skb is sent, it may be freed, and in some situations a
reference to it may still be in the child qdisc, because it was never
dequeued.

The crash log looks like this:

[   19.937538] ==================================================================
[   19.938300] BUG: KASAN: use-after-free in taprio_dequeue_soft+0x620/0x780
[   19.938968] Read of size 4 at addr ffff8881128628cc by task swapper/1/0
[   19.939612]
[   19.939772] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc3+ #97
[   19.940397] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qe4
[   19.941523] Call Trace:
[   19.941774]  <IRQ>
[   19.941985]  dump_stack+0x97/0xe0
[   19.942323]  print_address_description.constprop.0+0x3b/0x60
[   19.942884]  ? taprio_dequeue_soft+0x620/0x780
[   19.943325]  ? taprio_dequeue_soft+0x620/0x780
[   19.943767]  __kasan_report.cold+0x1a/0x32
[   19.944173]  ? taprio_dequeue_soft+0x620/0x780
[   19.944612]  kasan_report+0xe/0x20
[   19.944954]  taprio_dequeue_soft+0x620/0x780
[   19.945380]  __qdisc_run+0x164/0x18d0
[   19.945749]  net_tx_action+0x2c4/0x730
[   19.946124]  __do_softirq+0x268/0x7bc
[   19.946491]  irq_exit+0x17d/0x1b0
[   19.946824]  smp_apic_timer_interrupt+0xeb/0x380
[   19.947280]  apic_timer_interrupt+0xf/0x20
[   19.947687]  </IRQ>
[   19.947912] RIP: 0010:default_idle+0x2d/0x2d0
[   19.948345] Code: 00 00 41 56 41 55 65 44 8b 2d 3f 8d 7c 7c 41 54 55 53 0f 1f 44 00 00 e8 b1 b2 c5 fd e9 07 00 3
[   19.950166] RSP: 0018:ffff88811a3efda0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
[   19.950909] RAX: 0000000080000000 RBX: ffff88811a3a9600 RCX: ffffffff8385327e
[   19.951608] RDX: 1ffff110234752c0 RSI: 0000000000000000 RDI: ffffffff8385262f
[   19.952309] RBP: ffffed10234752c0 R08: 0000000000000001 R09: ffffed10234752c1
[   19.953009] R10: ffffed10234752c0 R11: ffff88811a3a9607 R12: 0000000000000001
[   19.953709] R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
[   19.954408]  ? default_idle_call+0x2e/0x70
[   19.954816]  ? default_idle+0x1f/0x2d0
[   19.955192]  default_idle_call+0x5e/0x70
[   19.955584]  do_idle+0x3d4/0x500
[   19.955909]  ? arch_cpu_idle_exit+0x40/0x40
[   19.956325]  ? _raw_spin_unlock_irqrestore+0x23/0x30
[   19.956829]  ? trace_hardirqs_on+0x30/0x160
[   19.957242]  cpu_startup_entry+0x19/0x20
[   19.957633]  start_secondary+0x2a6/0x380
[   19.958026]  ? set_cpu_sibling_map+0x18b0/0x18b0
[   19.958486]  secondary_startup_64+0xa4/0xb0
[   19.958921]
[   19.959078] Allocated by task 33:
[   19.959412]  save_stack+0x1b/0x80
[   19.959747]  __kasan_kmalloc.constprop.0+0xc2/0xd0
[   19.960222]  kmem_cache_alloc+0xe4/0x230
[   19.960617]  __alloc_skb+0x91/0x510
[   19.960967]  ndisc_alloc_skb+0x133/0x330
[   19.961358]  ndisc_send_ns+0x134/0x810
[   19.961735]  addrconf_dad_work+0xad5/0xf80
[   19.962144]  process_one_work+0x78e/0x13a0
[   19.962551]  worker_thread+0x8f/0xfa0
[   19.962919]  kthread+0x2ba/0x3b0
[   19.963242]  ret_from_fork+0x3a/0x50
[   19.963596]
[   19.963753] Freed by task 33:
[   19.964055]  save_stack+0x1b/0x80
[   19.964386]  __kasan_slab_free+0x12f/0x180
[   19.964830]  kmem_cache_free+0x80/0x290
[   19.965231]  ip6_mc_input+0x38a/0x4d0
[   19.965617]  ipv6_rcv+0x1a4/0x1d0
[   19.965948]  __netif_receive_skb_one_core+0xf2/0x180
[   19.966437]  netif_receive_skb+0x8c/0x3c0
[   19.966846]  br_handle_frame_finish+0x779/0x1310
[   19.967302]  br_handle_frame+0x42a/0x830
[   19.967694]  __netif_receive_skb_core+0xf0e/0x2a90
[   19.968167]  __netif_receive_skb_one_core+0x96/0x180
[   19.968658]  process_backlog+0x198/0x650
[   19.969047]  net_rx_action+0x2fa/0xaa0
[   19.969420]  __do_softirq+0x268/0x7bc
[   19.969785]
[   19.969940] The buggy address belongs to the object at ffff888112862840
[   19.969940]  which belongs to the cache skbuff_head_cache of size 224
[   19.971202] The buggy address is located 140 bytes inside of
[   19.971202]  224-byte region [ffff888112862840, ffff888112862920)
[   19.972344] The buggy address belongs to the page:
[   19.972820] page:ffffea00044a1800 refcount:1 mapcount:0 mapping:ffff88811a2bd1c0 index:0xffff8881128625c0 compo0
[   19.973930] flags: 0x8000000000010200(slab|head)
[   19.974388] raw: 8000000000010200 ffff88811a2ed650 ffff88811a2ed650 ffff88811a2bd1c0
[   19.975151] raw: ffff8881128625c0 0000000000190013 00000001ffffffff 0000000000000000
[   19.975915] page dumped because: kasan: bad access detected
[   19.976461] page_owner tracks the page as allocated
[   19.976946] page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NO)
[   19.978332]  prep_new_page+0x24b/0x330
[   19.978707]  get_page_from_freelist+0x2057/0x2c90
[   19.979170]  __alloc_pages_nodemask+0x218/0x590
[   19.979619]  new_slab+0x9d/0x300
[   19.979948]  ___slab_alloc.constprop.0+0x2f9/0x6f0
[   19.980421]  __slab_alloc.constprop.0+0x30/0x60
[   19.980870]  kmem_cache_alloc+0x201/0x230
[   19.981269]  __alloc_skb+0x91/0x510
[   19.981620]  alloc_skb_with_frags+0x78/0x4a0
[   19.982043]  sock_alloc_send_pskb+0x5eb/0x750
[   19.982476]  unix_stream_sendmsg+0x399/0x7f0
[   19.982904]  sock_sendmsg+0xe2/0x110
[   19.983262]  ____sys_sendmsg+0x4de/0x6d0
[   19.983660]  ___sys_sendmsg+0xe4/0x160
[   19.984032]  __sys_sendmsg+0xab/0x130
[   19.984396]  do_syscall_64+0xe7/0xae0
[   19.984761] page last free stack trace:
[   19.985142]  __free_pages_ok+0x432/0xbc0
[   19.985533]  qlist_free_all+0x56/0xc0
[   19.985907]  quarantine_reduce+0x149/0x170
[   19.986315]  __kasan_kmalloc.constprop.0+0x9e/0xd0
[   19.986791]  kmem_cache_alloc+0xe4/0x230
[   19.987182]  prepare_creds+0x24/0x440
[   19.987548]  do_faccessat+0x80/0x590
[   19.987906]  do_syscall_64+0xe7/0xae0
[   19.988276]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   19.988775]
[   19.988930] Memory state around the buggy address:
[   19.989402]  ffff888112862780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   19.990111]  ffff888112862800: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
[   19.990822] >ffff888112862880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   19.991529]                                               ^
[   19.992081]  ffff888112862900: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
[   19.992796]  ffff888112862980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: 5a781ccbd1 ("tc: Add support for configuring the taprio scheduler")
Reported-by: Michael Schmidt <michael.schmidt@eti.uni-siegen.de>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Acked-by: Andre Guedes <andre.guedes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-12 11:25:08 -07:00
arch arm64: dts: ls1043a: FMan erratum A050385 2020-03-06 21:55:32 -08:00
block block-5.6-2020-02-05 2020-02-06 06:15:23 +00:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 2020-02-20 15:15:16 -08:00
Documentation linux-next: DOC: RDS: Fix a typo in rds.txt 2020-03-09 10:06:07 -07:00
drivers net: mvmdio: avoid error message for optional IRQ 2020-03-12 00:03:30 -07:00
fs for-5.6-rc2-tag 2020-02-23 09:43:50 -08:00
include seg6: fix SRv6 L2 tunnels to use IANA-assigned protocol number 2020-03-11 23:49:30 -07:00
init Tracing updates: 2020-02-26 10:34:42 -08:00
ipc Revert "ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()" 2020-02-21 11:22:15 -08:00
kernel cgroup: memcg: net: do not associate sock with unrelated cgroup 2020-03-10 15:33:05 -07:00
lib Tracing updates: 2020-02-26 10:34:42 -08:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm net: memcg: late association of sock to memcg 2020-03-10 15:33:05 -07:00
net taprio: Fix sending packets without dequeueing them 2020-03-12 11:25:08 -07:00
samples Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
scripts kbuild: remove unneeded semicolon at the end of cmd_dtb_check 2020-02-27 02:24:34 +09:00
security Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 2020-02-20 15:15:16 -08:00
sound ASoC: Fixes for v5.6 2020-02-18 13:33:39 +01:00
tools selftests/net/fib_tests: update addr_metric_test for peer route testing 2020-03-03 14:43:16 -08:00
usr Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
virt KVM: Disable preemption in kvm_get_running_vcpu() 2020-02-12 12:19:35 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore selftest/lkdtm: Don't pollute 'git status' 2020-02-20 08:55:06 -07:00
.mailmap A handful of small documentation fixes that wandered in. 2020-02-07 13:03:10 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Hand MIPS over to Thomas 2020-02-24 22:43:18 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: remove Sathya Perla as Emulex NIC maintainer 2020-03-11 22:53:34 -07:00
Makefile kbuild: add dt_binding_check to PHONY in a correct place 2020-02-27 02:28:15 +09:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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.

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.