1. 21 Jul, 2017 2 commits
    • Gao Feng's avatar
      net: sched: Fix one possible panic when no destroy callback · c485792e
      Gao Feng authored
      commit c1a4872e upstream.
      
      When qdisc fail to init, qdisc_create would invoke the destroy callback
      to cleanup. But there is no check if the callback exists really. So it
      would cause the panic if there is no real destroy callback like the qdisc
      codel, fq, and so on.
      
      Take codel as an example following:
      When a malicious user constructs one invalid netlink msg, it would cause
      codel_init->codel_change->nla_parse_nested failed.
      Then kernel would invoke the destroy callback directly but qdisc codel
      doesn't define one. It causes one panic as a result.
      
      Now add one the check for destroy to avoid the possible panic.
      
      Fixes: 87b60cfa ("net_sched: fix error recovery at qdisc creation")
      Signed-off-by: default avatarGao Feng <gfree.wind@vip.163.com>
      Acked-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c485792e
    • Eric Dumazet's avatar
      net_sched: fix error recovery at qdisc creation · 0be4c96e
      Eric Dumazet authored
      commit 87b60cfa upstream.
      
      Dmitry reported uses after free in qdisc code [1]
      
      The problem here is that ops->init() can return an error.
      
      qdisc_create_dflt() then call ops->destroy(),
      while qdisc_create() does _not_ call it.
      
      Four qdisc chose to call their own ops->destroy(), assuming their caller
      would not.
      
      This patch makes sure qdisc_create() calls ops->destroy()
      and fixes the four qdisc to avoid double free.
      
      [1]
      BUG: KASAN: use-after-free in mq_destroy+0x242/0x290 net/sched/sch_mq.c:33 at addr ffff8801d415d440
      Read of size 8 by task syz-executor2/5030
      CPU: 0 PID: 5030 Comm: syz-executor2 Not tainted 4.3.5-smp-DEV #119
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
       0000000000000046 ffff8801b435b870 ffffffff81bbbed4 ffff8801db000400
       ffff8801d415d440 ffff8801d415dc40 ffff8801c4988510 ffff8801b435b898
       ffffffff816682b1 ffff8801b435b928 ffff8801d415d440 ffff8801c49880c0
      Call Trace:
       [<ffffffff81bbbed4>] __dump_stack lib/dump_stack.c:15 [inline]
       [<ffffffff81bbbed4>] dump_stack+0x6c/0x98 lib/dump_stack.c:51
       [<ffffffff816682b1>] kasan_object_err+0x21/0x70 mm/kasan/report.c:158
       [<ffffffff81668524>] print_address_description mm/kasan/report.c:196 [inline]
       [<ffffffff81668524>] kasan_report_error+0x1b4/0x4b0 mm/kasan/report.c:285
       [<ffffffff81668953>] kasan_report mm/kasan/report.c:305 [inline]
       [<ffffffff81668953>] __asan_report_load8_noabort+0x43/0x50 mm/kasan/report.c:326
       [<ffffffff82527b02>] mq_destroy+0x242/0x290 net/sched/sch_mq.c:33
       [<ffffffff82524bdd>] qdisc_destroy+0x12d/0x290 net/sched/sch_generic.c:953
       [<ffffffff82524e30>] qdisc_create_dflt+0xf0/0x120 net/sched/sch_generic.c:848
       [<ffffffff8252550d>] attach_default_qdiscs net/sched/sch_generic.c:1029 [inline]
       [<ffffffff8252550d>] dev_activate+0x6ad/0x880 net/sched/sch_generic.c:1064
       [<ffffffff824b1db1>] __dev_open+0x221/0x320 net/core/dev.c:1403
       [<ffffffff824b24ce>] __dev_change_flags+0x15e/0x3e0 net/core/dev.c:6858
       [<ffffffff824b27de>] dev_change_flags+0x8e/0x140 net/core/dev.c:6926
       [<ffffffff824f5bf6>] dev_ifsioc+0x446/0x890 net/core/dev_ioctl.c:260
       [<ffffffff824f61fa>] dev_ioctl+0x1ba/0xb80 net/core/dev_ioctl.c:546
       [<ffffffff82430509>] sock_do_ioctl+0x99/0xb0 net/socket.c:879
       [<ffffffff82430d30>] sock_ioctl+0x2a0/0x390 net/socket.c:958
       [<ffffffff816f3b68>] vfs_ioctl fs/ioctl.c:44 [inline]
       [<ffffffff816f3b68>] do_vfs_ioctl+0x8a8/0xe50 fs/ioctl.c:611
       [<ffffffff816f41a4>] SYSC_ioctl fs/ioctl.c:626 [inline]
       [<ffffffff816f41a4>] SyS_ioctl+0x94/0xc0 fs/ioctl.c:617
       [<ffffffff8123e357>] entry_SYSCALL_64_fastpath+0x12/0x17
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0be4c96e
  2. 15 Jul, 2017 38 commits