1. 31 Mar, 2018 4 commits
    • Guillaume Nault's avatar
      ppp: avoid loop in xmit recursion detection code · fe3627f6
      Guillaume Nault authored
      
      [ Upstream commit 6d066734 ]
      
      We already detect situations where a PPP channel sends packets back to
      its upper PPP device. While this is enough to avoid deadlocking on xmit
      locks, this doesn't prevent packets from looping between the channel
      and the unit.
      
      The problem is that ppp_start_xmit() enqueues packets in ppp->file.xq
      before checking for xmit recursion. Therefore, __ppp_xmit_process()
      might dequeue a packet from ppp->file.xq and send it on the channel
      which, in turn, loops it back on the unit. Then ppp_start_xmit()
      queues the packet back to ppp->file.xq and __ppp_xmit_process() picks
      it up and sends it again through the channel. Therefore, the packet
      will loop between __ppp_xmit_process() and ppp_start_xmit() until some
      other part of the xmit path drops it.
      
      For L2TP, we rapidly fill the skb's headroom and pppol2tp_xmit() drops
      the packet after a few iterations. But PPTP reallocates the headroom
      if necessary, letting the loop run and exhaust the machine resources
      (as reported in https://bugzilla.kernel.org/show_bug.cgi?id=199109).
      
      Fix this by letting __ppp_xmit_process() enqueue the skb to
      ppp->file.xq, so that we can check for recursion before adding it to
      the queue. Now ppp_xmit_process() can drop the packet when recursion is
      detected.
      
      __ppp_channel_push() is a bit special. It calls __ppp_xmit_process()
      without having any actual packet to send. This is used by
      ppp_output_wakeup() to re-enable transmission on the parent unit (for
      implementations like ppp_async.c, where the .start_xmit() function
      might not consume the skb, leaving it in ppp->xmit_pending and
      disabling transmission).
      Therefore, __ppp_xmit_process() needs to handle the case where skb is
      NULL, dequeuing as many packets as possible from ppp->file.xq.
      Reported-by: default avatarxu heng <xuheng333@zoho.com>
      Fixes: 55454a56 ("ppp: avoid dealock on recursive xmit")
      Signed-off-by: default avatarGuillaume Nault <g.nault@alphalink.fr>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fe3627f6
    • Roman Mashak's avatar
      net sched actions: return explicit error when tunnel_key mode is not specified · 4f2f7a07
      Roman Mashak authored
      
      [ Upstream commit 51d4740f ]
      
      If set/unset mode of the tunnel_key action is not provided, ->init() still
      returns 0, and the caller proceeds with bogus 'struct tc_action *' object,
      this results in crash:
      
      % tc actions add action tunnel_key src_ip 1.1.1.1 dst_ip 2.2.2.1 id 7 index 1
      
      [   35.805515] general protection fault: 0000 [#1] SMP PTI
      [   35.806161] Modules linked in: act_tunnel_key kvm_intel kvm irqbypass
      crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel aes_x86_64
      crypto_simd glue_helper cryptd serio_raw
      [   35.808233] CPU: 1 PID: 428 Comm: tc Not tainted 4.16.0-rc4+ #286
      [   35.808929] RIP: 0010:tcf_action_init+0x90/0x190
      [   35.809457] RSP: 0018:ffffb8edc068b9a0 EFLAGS: 00010206
      [   35.810053] RAX: 1320c000000a0003 RBX: 0000000000000001 RCX: 0000000000000000
      [   35.810866] RDX: 0000000000000070 RSI: 0000000000007965 RDI: ffffb8edc068b910
      [   35.811660] RBP: ffffb8edc068b9d0 R08: 0000000000000000 R09: ffffb8edc068b808
      [   35.812463] R10: ffffffffc02bf040 R11: 0000000000000040 R12: ffffb8edc068bb38
      [   35.813235] R13: 0000000000000000 R14: 0000000000000000 R15: ffffb8edc068b910
      [   35.814006] FS:  00007f3d0d8556c0(0000) GS:ffff91d1dbc40000(0000)
      knlGS:0000000000000000
      [   35.814881] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [   35.815540] CR2: 000000000043f720 CR3: 0000000019248001 CR4: 00000000001606a0
      [   35.816457] Call Trace:
      [   35.817158]  tc_ctl_action+0x11a/0x220
      [   35.817795]  rtnetlink_rcv_msg+0x23d/0x2e0
      [   35.818457]  ? __slab_alloc+0x1c/0x30
      [   35.819079]  ? __kmalloc_node_track_caller+0xb1/0x2b0
      [   35.819544]  ? rtnl_calcit.isra.30+0xe0/0xe0
      [   35.820231]  netlink_rcv_skb+0xce/0x100
      [   35.820744]  netlink_unicast+0x164/0x220
      [   35.821500]  netlink_sendmsg+0x293/0x370
      [   35.822040]  sock_sendmsg+0x30/0x40
      [   35.822508]  ___sys_sendmsg+0x2c5/0x2e0
      [   35.823149]  ? pagecache_get_page+0x27/0x220
      [   35.823714]  ? filemap_fault+0xa2/0x640
      [   35.824423]  ? page_add_file_rmap+0x108/0x200
      [   35.825065]  ? alloc_set_pte+0x2aa/0x530
      [   35.825585]  ? finish_fault+0x4e/0x70
      [   35.826140]  ? __handle_mm_fault+0xbc1/0x10d0
      [   35.826723]  ? __sys_sendmsg+0x41/0x70
      [   35.827230]  __sys_sendmsg+0x41/0x70
      [   35.827710]  do_syscall_64+0x68/0x120
      [   35.828195]  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
      [   35.828859] RIP: 0033:0x7f3d0ca4da67
      [   35.829331] RSP: 002b:00007ffc9f284338 EFLAGS: 00000246 ORIG_RAX:
      000000000000002e
      [   35.830304] RAX: ffffffffffffffda RBX: 00007ffc9f284460 RCX: 00007f3d0ca4da67
      [   35.831247] RDX: 0000000000000000 RSI: 00007ffc9f2843b0 RDI: 0000000000000003
      [   35.832167] RBP: 000000005aa6a7a9 R08: 0000000000000001 R09: 0000000000000000
      [   35.833075] R10: 00000000000005f1 R11: 0000000000000246 R12: 0000000000000000
      [   35.833997] R13: 00007ffc9f2884c0 R14: 0000000000000001 R15: 0000000000674640
      [   35.834923] Code: 24 30 bb 01 00 00 00 45 31 f6 eb 5e 8b 50 08 83 c2 07 83 e2
      fc 83 c2 70 49 8b 07 48 8b 40 70 48 85 c0 74 10 48 89 14 24 4c 89 ff <ff> d0 48
      8b 14 24 48 01 c2 49 01 d6 45 85 ed 74 05 41 83 47 2c
      [   35.837442] RIP: tcf_action_init+0x90/0x190 RSP: ffffb8edc068b9a0
      [   35.838291] ---[ end trace a095c06ee4b97a26 ]---
      
      Fixes: d0f6dd8a ("net/sched: Introduce act_tunnel_key")
      Signed-off-by: default avatarRoman Mashak <mrv@mojatatu.com>
      Acked-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4f2f7a07
    • Greg Kroah-Hartman's avatar
      Revert "genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQs" · 6c9ca571
      Greg Kroah-Hartman authored
      This reverts commit f2596a98 which is
      commit 382bd4de upstream.
      
      It causes too many problems with the stable tree, and would require too
      many other things to be backported, so just revert it.
      Reported-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Hans de Goede <hdegoede@redhat.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Sasha Levin <alexander.levin@microsoft.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6c9ca571
    • Johannes Thumshirn's avatar
      scsi: sg: don't return bogus Sg_requests · 6505dd1f
      Johannes Thumshirn authored
      commit 48ae8484 upstream.
      
      If the list search in sg_get_rq_mark() fails to find a valid request, we
      return a bogus element. This then can later lead to a GPF in
      sg_remove_scat().
      
      So don't return bogus Sg_requests in sg_get_rq_mark() but NULL in case
      the list search doesn't find a valid request.
      Signed-off-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
      Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Cc: Hannes Reinecke <hare@suse.de>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Doug Gilbert <dgilbert@interlog.com>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Acked-by: default avatarDoug Gilbert <dgilbert@interlog.com>
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Cc: Tony Battersby <tonyb@cybernetics.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6505dd1f
  2. 28 Mar, 2018 36 commits