1. 14 May, 2017 2 commits
  2. 08 May, 2017 22 commits
  3. 03 May, 2017 16 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.4.66 · 0c49a2c1
      Greg Kroah-Hartman authored
      0c49a2c1
    • Josh Poimboeuf's avatar
      ftrace/x86: Fix triple fault with graph tracing and suspend-to-ram · 9c4a4755
      Josh Poimboeuf authored
      commit 34a477e5 upstream.
      
      On x86-32, with CONFIG_FIRMWARE and multiple CPUs, if you enable function
      graph tracing and then suspend to RAM, it will triple fault and reboot when
      it resumes.
      
      The first fault happens when booting a secondary CPU:
      
      startup_32_smp()
        load_ucode_ap()
          prepare_ftrace_return()
            ftrace_graph_is_dead()
              (accesses 'kill_ftrace_graph')
      
      The early head_32.S code calls into load_ucode_ap(), which has an an
      ftrace hook, so it calls prepare_ftrace_return(), which calls
      ftrace_graph_is_dead(), which tries to access the global
      'kill_ftrace_graph' variable with a virtual address, causing a fault
      because the CPU is still in real mode.
      
      The fix is to add a check in prepare_ftrace_return() to make sure it's
      running in protected mode before continuing.  The check makes sure the
      stack pointer is a virtual kernel address.  It's a bit of a hack, but
      it's not very intrusive and it works well enough.
      
      For reference, here are a few other (more difficult) ways this could
      have potentially been fixed:
      
      - Move startup_32_smp()'s call to load_ucode_ap() down to *after* paging
        is enabled.  (No idea what that would break.)
      
      - Track down load_ucode_ap()'s entire callee tree and mark all the
        functions 'notrace'.  (Probably not realistic.)
      
      - Pause graph tracing in ftrace_suspend_notifier_call() or bringup_cpu()
        or __cpu_up(), and ensure that the pause facility can be queried from
        real mode.
      Reported-by: default avatarPaul Menzel <pmenzel@molgen.mpg.de>
      Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
      Tested-by: default avatarPaul Menzel <pmenzel@molgen.mpg.de>
      Reviewed-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net>
      Cc: linux-acpi@vger.kernel.org
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Len Brown <lenb@kernel.org>
      Link: http://lkml.kernel.org/r/5c1272269a580660703ed2eccf44308e790c7a98.1492123841.git.jpoimboe@redhat.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9c4a4755
    • Vineet Gupta's avatar
      ARCv2: save r30 on kernel entry as gcc uses it for code-gen · 1aefe328
      Vineet Gupta authored
      commit ecd43afd upstream.
      
      This is not exposed to userspace debugers yet, which can be done
      independently as a seperate patch !
      Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1aefe328
    • J. Bruce Fields's avatar
      nfsd: check for oversized NFSv2/v3 arguments · 82a0d8aa
      J. Bruce Fields authored
      commit e6838a29 upstream.
      
      A client can append random data to the end of an NFSv2 or NFSv3 RPC call
      without our complaining; we'll just stop parsing at the end of the
      expected data and ignore the rest.
      
      Encoded arguments and replies are stored together in an array of pages,
      and if a call is too large it could leave inadequate space for the
      reply.  This is normally OK because NFS RPC's typically have either
      short arguments and long replies (like READ) or long arguments and short
      replies (like WRITE).  But a client that sends an incorrectly long reply
      can violate those assumptions.  This was observed to cause crashes.
      
      Also, several operations increment rq_next_page in the decode routine
      before checking the argument size, which can leave rq_next_page pointing
      well past the end of the page array, causing trouble later in
      svc_free_pages.
      
      So, following a suggestion from Neil Brown, add a central check to
      enforce our expectation that no NFSv2/v3 call has both a large call and
      a large reply.
      
      As followup we may also want to rewrite the encoding routines to check
      more carefully that they aren't running off the end of the page array.
      
      We may also consider rejecting calls that have any extra garbage
      appended.  That would be safer, and within our rights by spec, but given
      the age of our server and the NFS protocol, and the fact that we've
      never enforced this before, we may need to balance that against the
      possibility of breaking some oddball client.
      Reported-by: default avatarTuomas Haanpää <thaan@synopsys.com>
      Reported-by: default avatarAri Kauppi <ari@synopsys.com>
      Reviewed-by: default avatarNeilBrown <neilb@suse.com>
      Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      82a0d8aa
    • Dmitry Torokhov's avatar
      Input: i8042 - add Clevo P650RS to the i8042 reset list · 2032eebe
      Dmitry Torokhov authored
      commit 7c5bb4ac upstream.
      
      Clevo P650RS and other similar devices require i8042 to be reset in order
      to detect Synaptics touchpad.
      Reported-by: default avatarPaweł Bylica <chfast@gmail.com>
      Tested-by: default avatarEd Bordin <edbordin@gmail.com>
      Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=190301Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2032eebe
    • Al Viro's avatar
      p9_client_readdir() fix · 91ce8d13
      Al Viro authored
      commit 71d6ad08 upstream.
      
      Don't assume that server is sane and won't return more data than
      asked for.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      91ce8d13
    • James Cowgill's avatar
      MIPS: Avoid BUG warning in arch_check_elf · 3bf08099
      James Cowgill authored
      commit c46f59e9 upstream.
      
      arch_check_elf contains a usage of current_cpu_data that will call
      smp_processor_id() with preemption enabled and therefore triggers a
      "BUG: using smp_processor_id() in preemptible" warning when an fpxx
      executable is loaded.
      
      As a follow-up to commit b244614a ("MIPS: Avoid a BUG warning during
      prctl(PR_SET_FP_MODE, ...)"), apply the same fix to arch_check_elf by
      using raw_current_cpu_data instead. The rationale quoted from the previous
      commit:
      
      "It is assumed throughout the kernel that if any CPU has an FPU, then
      all CPUs would have an FPU as well, so it is safe to perform the check
      with preemption enabled - change the code to use raw_ variant of the
      check to avoid the warning."
      
      Fixes: 46490b57 ("MIPS: kernel: elf: Improve the overall ABI and FPU mode checks")
      Signed-off-by: default avatarJames Cowgill <James.Cowgill@imgtec.com>
      Cc: linux-mips@linux-mips.org
      Patchwork: https://patchwork.linux-mips.org/patch/15951/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3bf08099
    • James Hogan's avatar
      MIPS: KGDB: Use kernel context for sleeping threads · 1c26c382
      James Hogan authored
      commit 162b270c upstream.
      
      KGDB is a kernel debug stub and it can't be used to debug userland as it
      can only safely access kernel memory.
      
      On MIPS however KGDB has always got the register state of sleeping
      processes from the userland register context at the beginning of the
      kernel stack. This is meaningless for kernel threads (which never enter
      userland), and for user threads it prevents the user seeing what it is
      doing while in the kernel:
      
      (gdb) info threads
        Id   Target Id         Frame
        ...
        3    Thread 2 (kthreadd) 0x0000000000000000 in ?? ()
        2    Thread 1 (init)   0x000000007705c4b4 in ?? ()
        1    Thread -2 (shadowCPU0) 0xffffffff8012524c in arch_kgdb_breakpoint () at arch/mips/kernel/kgdb.c:201
      
      Get the register state instead from the (partial) kernel register
      context stored in the task's thread_struct for resume() to restore. All
      threads now correctly appear to be in context_switch():
      
      (gdb) info threads
        Id   Target Id         Frame
        ...
        3    Thread 2 (kthreadd) context_switch (rq=<optimized out>, cookie=..., next=<optimized out>, prev=0x0) at kernel/sched/core.c:2903
        2    Thread 1 (init)   context_switch (rq=<optimized out>, cookie=..., next=<optimized out>, prev=0x0) at kernel/sched/core.c:2903
        1    Thread -2 (shadowCPU0) 0xffffffff8012524c in arch_kgdb_breakpoint () at arch/mips/kernel/kgdb.c:201
      
      Call clobbered registers which aren't saved and exception registers
      (BadVAddr & Cause) which can't be easily determined without stack
      unwinding are reported as 0. The PC is taken from the return address,
      such that the state presented matches that found immediately after
      returning from resume().
      
      Fixes: 88547001 ("[MIPS] kgdb: add arch support for the kernel's kgdb core")
      Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Cc: Jason Wessel <jason.wessel@windriver.com>
      Cc: linux-mips@linux-mips.org
      Patchwork: https://patchwork.linux-mips.org/patch/15829/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1c26c382
    • Takashi Iwai's avatar
      ALSA: seq: Don't break snd_use_lock_sync() loop by timeout · 555f7710
      Takashi Iwai authored
      commit 4e7655fd upstream.
      
      The snd_use_lock_sync() (thus its implementation
      snd_use_lock_sync_helper()) has the 5 seconds timeout to break out of
      the sync loop.  It was introduced from the beginning, just to be
      "safer", in terms of avoiding the stupid bugs.
      
      However, as Ben Hutchings suggested, this timeout rather introduces a
      potential leak or use-after-free that was apparently fixed by the
      commit 2d7d5400 ("ALSA: seq: Fix race during FIFO resize"):
      for example, snd_seq_fifo_event_in() -> snd_seq_event_dup() ->
      copy_from_user() could block for a long time, and snd_use_lock_sync()
      goes timeout and still leaves the cell at releasing the pool.
      
      For fixing such a problem, we remove the break by the timeout while
      still keeping the warning.
      Suggested-by: default avatarBen Hutchings <ben.hutchings@codethink.co.uk>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      555f7710
    • Takashi Sakamoto's avatar
      ALSA: firewire-lib: fix inappropriate assignment between signed/unsigned type · 8cbaf11c
      Takashi Sakamoto authored
      commit dfb00a56 upstream.
      
      An abstraction of asynchronous transaction for transmission of MIDI
      messages was introduced in Linux v4.4. Each driver can utilize this
      abstraction to transfer MIDI messages via fixed-length payload of
      transaction to a certain unit address. Filling payload of the transaction
      is done by callback. In this callback, each driver can return negative
      error code, however current implementation assigns the return value to
      unsigned variable.
      
      This commit changes type of the variable to fix the bug.
      Reported-by: default avatarJulia Lawall <Julia.Lawall@lip6.fr>
      Fixes: 585d7cba ("ALSA: firewire-lib: add helper functions for asynchronous transactions to transfer MIDI messages")
      Signed-off-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8cbaf11c
    • Jamie Bainbridge's avatar
      ipv6: check raw payload size correctly in ioctl · 5e52fffb
      Jamie Bainbridge authored
      [ Upstream commit 105f5528 ]
      
      In situations where an skb is paged, the transport header pointer and
      tail pointer can be the same because the skb contents are in frags.
      
      This results in ioctl(SIOCINQ/FIONREAD) incorrectly returning a
      length of 0 when the length to receive is actually greater than zero.
      
      skb->len is already correctly set in ip6_input_finish() with
      pskb_pull(), so use skb->len as it always returns the correct result
      for both linear and paged data.
      Signed-off-by: default avatarJamie Bainbridge <jbainbri@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5e52fffb
    • WANG Cong's avatar
      ipv6: check skb->protocol before lookup for nexthop · befb9254
      WANG Cong authored
      [ Upstream commit 199ab00f ]
      
      Andrey reported a out-of-bound access in ip6_tnl_xmit(), this
      is because we use an ipv4 dst in ip6_tnl_xmit() and cast an IPv4
      neigh key as an IPv6 address:
      
              neigh = dst_neigh_lookup(skb_dst(skb),
                                       &ipv6_hdr(skb)->daddr);
              if (!neigh)
                      goto tx_err_link_failure;
      
              addr6 = (struct in6_addr *)&neigh->primary_key; // <=== HERE
              addr_type = ipv6_addr_type(addr6);
      
              if (addr_type == IPV6_ADDR_ANY)
                      addr6 = &ipv6_hdr(skb)->daddr;
      
              memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
      
      Also the network header of the skb at this point should be still IPv4
      for 4in6 tunnels, we shold not just use it as IPv6 header.
      
      This patch fixes it by checking if skb->protocol is ETH_P_IPV6: if it
      is, we are safe to do the nexthop lookup using skb_dst() and
      ipv6_hdr(skb)->daddr; if not (aka IPv4), we have no clue about which
      dest address we can pick here, we have to rely on callers to fill it
      from tunnel config, so just fall to ip6_route_output() to make the
      decision.
      
      Fixes: ea3dc960 ("ip6_tunnel: Add support for wildcard tunnel endpoints.")
      Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Tested-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Cc: Steffen Klassert <steffen.klassert@secunet.com>
      Signed-off-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>
      befb9254
    • Herbert Xu's avatar
      macvlan: Fix device ref leak when purging bc_queue · 114f0c66
      Herbert Xu authored
      [ Upstream commit f6478218 ]
      
      When a parent macvlan device is destroyed we end up purging its
      broadcast queue without dropping the device reference count on
      the packet source device.  This causes the source device to linger.
      
      This patch drops that reference count.
      
      Fixes: 260916df ("macvlan: Fix potential use-after free for...")
      Reported-by: default avatarJoe Ghalam <Joe.Ghalam@dell.com>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      114f0c66
    • Nikolay Aleksandrov's avatar
      ip6mr: fix notification device destruction · bdeb026d
      Nikolay Aleksandrov authored
      [ Upstream commit 723b929c ]
      
      Andrey Konovalov reported a BUG caused by the ip6mr code which is caused
      because we call unregister_netdevice_many for a device that is already
      being destroyed. In IPv4's ipmr that has been resolved by two commits
      long time ago by introducing the "notify" parameter to the delete
      function and avoiding the unregister when called from a notifier, so
      let's do the same for ip6mr.
      
      The trace from Andrey:
      ------------[ cut here ]------------
      kernel BUG at net/core/dev.c:6813!
      invalid opcode: 0000 [#1] SMP KASAN
      Modules linked in:
      CPU: 1 PID: 1165 Comm: kworker/u4:3 Not tainted 4.11.0-rc7+ #251
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
      01/01/2011
      Workqueue: netns cleanup_net
      task: ffff880069208000 task.stack: ffff8800692d8000
      RIP: 0010:rollback_registered_many+0x348/0xeb0 net/core/dev.c:6813
      RSP: 0018:ffff8800692de7f0 EFLAGS: 00010297
      RAX: ffff880069208000 RBX: 0000000000000002 RCX: 0000000000000001
      RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88006af90569
      RBP: ffff8800692de9f0 R08: ffff8800692dec60 R09: 0000000000000000
      R10: 0000000000000006 R11: 0000000000000000 R12: ffff88006af90070
      R13: ffff8800692debf0 R14: dffffc0000000000 R15: ffff88006af90000
      FS:  0000000000000000(0000) GS:ffff88006cb00000(0000)
      knlGS:0000000000000000
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 00007fe7e897d870 CR3: 00000000657e7000 CR4: 00000000000006e0
      Call Trace:
       unregister_netdevice_many.part.105+0x87/0x440 net/core/dev.c:7881
       unregister_netdevice_many+0xc8/0x120 net/core/dev.c:7880
       ip6mr_device_event+0x362/0x3f0 net/ipv6/ip6mr.c:1346
       notifier_call_chain+0x145/0x2f0 kernel/notifier.c:93
       __raw_notifier_call_chain kernel/notifier.c:394
       raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
       call_netdevice_notifiers_info+0x51/0x90 net/core/dev.c:1647
       call_netdevice_notifiers net/core/dev.c:1663
       rollback_registered_many+0x919/0xeb0 net/core/dev.c:6841
       unregister_netdevice_many.part.105+0x87/0x440 net/core/dev.c:7881
       unregister_netdevice_many net/core/dev.c:7880
       default_device_exit_batch+0x4fa/0x640 net/core/dev.c:8333
       ops_exit_list.isra.4+0x100/0x150 net/core/net_namespace.c:144
       cleanup_net+0x5a8/0xb40 net/core/net_namespace.c:463
       process_one_work+0xc04/0x1c10 kernel/workqueue.c:2097
       worker_thread+0x223/0x19c0 kernel/workqueue.c:2231
       kthread+0x35e/0x430 kernel/kthread.c:231
       ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
      Code: 3c 32 00 0f 85 70 0b 00 00 48 b8 00 02 00 00 00 00 ad de 49 89
      47 78 e9 93 fe ff ff 49 8d 57 70 49 8d 5f 78 eb 9e e8 88 7a 14 fe <0f>
      0b 48 8b 9d 28 fe ff ff e8 7a 7a 14 fe 48 b8 00 00 00 00 00
      RIP: rollback_registered_many+0x348/0xeb0 RSP: ffff8800692de7f0
      ---[ end trace e0b29c57e9b3292c ]---
      Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarNikolay Aleksandrov <nikolay@cumulusnetworks.com>
      Tested-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bdeb026d
    • Tushar Dave's avatar
      netpoll: Check for skb->queue_mapping · 25c10402
      Tushar Dave authored
      [ Upstream commit c70b17b7 ]
      
      Reducing real_num_tx_queues needs to be in sync with skb queue_mapping
      otherwise skbs with queue_mapping greater than real_num_tx_queues
      can be sent to the underlying driver and can result in kernel panic.
      
      One such event is running netconsole and enabling VF on the same
      device. Or running netconsole and changing number of tx queues via
      ethtool on same device.
      
      e.g.
      Unable to handle kernel NULL pointer dereference
      tsk->{mm,active_mm}->context = 0000000000001525
      tsk->{mm,active_mm}->pgd = fff800130ff9a000
                    \|/ ____ \|/
                    "@'/ .. \`@"
                    /_| \__/ |_\
                       \__U_/
      kworker/48:1(475): Oops [#1]
      CPU: 48 PID: 475 Comm: kworker/48:1 Tainted: G           OE
      4.11.0-rc3-davem-net+ #7
      Workqueue: events queue_process
      task: fff80013113299c0 task.stack: fff800131132c000
      TSTATE: 0000004480e01600 TPC: 00000000103f9e3c TNPC: 00000000103f9e40 Y:
      00000000    Tainted: G           OE
      TPC: <ixgbe_xmit_frame_ring+0x7c/0x6c0 [ixgbe]>
      g0: 0000000000000000 g1: 0000000000003fff g2: 0000000000000000 g3:
      0000000000000001
      g4: fff80013113299c0 g5: fff8001fa6808000 g6: fff800131132c000 g7:
      00000000000000c0
      o0: fff8001fa760c460 o1: fff8001311329a50 o2: fff8001fa7607504 o3:
      0000000000000003
      o4: fff8001f96e63a40 o5: fff8001311d77ec0 sp: fff800131132f0e1 ret_pc:
      000000000049ed94
      RPC: <set_next_entity+0x34/0xb80>
      l0: 0000000000000000 l1: 0000000000000800 l2: 0000000000000000 l3:
      0000000000000000
      l4: 000b2aa30e34b10d l5: 0000000000000000 l6: 0000000000000000 l7:
      fff8001fa7605028
      i0: fff80013111a8a00 i1: fff80013155a0780 i2: 0000000000000000 i3:
      0000000000000000
      i4: 0000000000000000 i5: 0000000000100000 i6: fff800131132f1a1 i7:
      00000000103fa4b0
      I7: <ixgbe_xmit_frame+0x30/0xa0 [ixgbe]>
      Call Trace:
       [00000000103fa4b0] ixgbe_xmit_frame+0x30/0xa0 [ixgbe]
       [0000000000998c74] netpoll_start_xmit+0xf4/0x200
       [0000000000998e10] queue_process+0x90/0x160
       [0000000000485fa8] process_one_work+0x188/0x480
       [0000000000486410] worker_thread+0x170/0x4c0
       [000000000048c6b8] kthread+0xd8/0x120
       [0000000000406064] ret_from_fork+0x1c/0x2c
       [0000000000000000]           (null)
      Disabling lock debugging due to kernel taint
      Caller[00000000103fa4b0]: ixgbe_xmit_frame+0x30/0xa0 [ixgbe]
      Caller[0000000000998c74]: netpoll_start_xmit+0xf4/0x200
      Caller[0000000000998e10]: queue_process+0x90/0x160
      Caller[0000000000485fa8]: process_one_work+0x188/0x480
      Caller[0000000000486410]: worker_thread+0x170/0x4c0
      Caller[000000000048c6b8]: kthread+0xd8/0x120
      Caller[0000000000406064]: ret_from_fork+0x1c/0x2c
      Caller[0000000000000000]:           (null)
      Signed-off-by: default avatarTushar Dave <tushar.n.dave@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      25c10402
    • David Ahern's avatar
      net: ipv6: RTF_PCPU should not be settable from userspace · f6b94906
      David Ahern authored
      [ Upstream commit 557c44be ]
      
      Andrey reported a fault in the IPv6 route code:
      
      kasan: GPF could be caused by NULL-ptr deref or user memory access
      general protection fault: 0000 [#1] SMP KASAN
      Modules linked in:
      CPU: 1 PID: 4035 Comm: a.out Not tainted 4.11.0-rc7+ #250
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
      task: ffff880069809600 task.stack: ffff880062dc8000
      RIP: 0010:ip6_rt_cache_alloc+0xa6/0x560 net/ipv6/route.c:975
      RSP: 0018:ffff880062dced30 EFLAGS: 00010206
      RAX: dffffc0000000000 RBX: ffff8800670561c0 RCX: 0000000000000006
      RDX: 0000000000000003 RSI: ffff880062dcfb28 RDI: 0000000000000018
      RBP: ffff880062dced68 R08: 0000000000000001 R09: 0000000000000000
      R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
      R13: ffff880062dcfb28 R14: dffffc0000000000 R15: 0000000000000000
      FS:  00007feebe37e7c0(0000) GS:ffff88006cb00000(0000) knlGS:0000000000000000
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 00000000205a0fe4 CR3: 000000006b5c9000 CR4: 00000000000006e0
      Call Trace:
       ip6_pol_route+0x1512/0x1f20 net/ipv6/route.c:1128
       ip6_pol_route_output+0x4c/0x60 net/ipv6/route.c:1212
      ...
      
      Andrey's syzkaller program passes rtmsg.rtmsg_flags with the RTF_PCPU bit
      set. Flags passed to the kernel are blindly copied to the allocated
      rt6_info by ip6_route_info_create making a newly inserted route appear
      as though it is a per-cpu route. ip6_rt_cache_alloc sees the flag set
      and expects rt->dst.from to be set - which it is not since it is not
      really a per-cpu copy. The subsequent call to __ip6_dst_alloc then
      generates the fault.
      
      Fix by checking for the flag and failing with EINVAL.
      
      Fixes: d52d3997 ("ipv6: Create percpu rt6_info")
      Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarDavid Ahern <dsa@cumulusnetworks.com>
      Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
      Tested-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f6b94906