1. 05 5月, 2019 5 次提交
    • W
      ipv6: invert flowlabel sharing check in process and user mode · f78ec0cd
      Willem de Bruijn 提交于
      [ Upstream commit 95c169251bf734aa555a1e8043e4d88ec97a04ec ]
      
      A request for a flowlabel fails in process or user exclusive mode must
      fail if the caller pid or uid does not match. Invert the test.
      
      Previously, the test was unsafe wrt PID recycling, but indeed tested
      for inequality: fl1->owner != fl->owner
      
      Fixes: 4f82f457 ("net ip6 flowlabel: Make owner a union of struct pid* and kuid_t")
      Signed-off-by: NWillem de Bruijn <willemb@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f78ec0cd
    • E
      ipv6/flowlabel: wait rcu grace period before put_pid() · 39eddbb7
      Eric Dumazet 提交于
      [ Upstream commit 6c0afef5fb0c27758f4d52b2210c61b6bd8b4470 ]
      
      syzbot was able to catch a use-after-free read in pid_nr_ns() [1]
      
      ip6fl_seq_show() seems to use RCU protection, dereferencing fl->owner.pid
      but fl_free() releases fl->owner.pid before rcu grace period is started.
      
      [1]
      
      BUG: KASAN: use-after-free in pid_nr_ns+0x128/0x140 kernel/pid.c:407
      Read of size 4 at addr ffff888094012a04 by task syz-executor.0/18087
      
      CPU: 0 PID: 18087 Comm: syz-executor.0 Not tainted 5.1.0-rc6+ #89
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      Call Trace:
       __dump_stack lib/dump_stack.c:77 [inline]
       dump_stack+0x172/0x1f0 lib/dump_stack.c:113
       print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
       kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
       __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131
       pid_nr_ns+0x128/0x140 kernel/pid.c:407
       ip6fl_seq_show+0x2f8/0x4f0 net/ipv6/ip6_flowlabel.c:794
       seq_read+0xad3/0x1130 fs/seq_file.c:268
       proc_reg_read+0x1fe/0x2c0 fs/proc/inode.c:227
       do_loop_readv_writev fs/read_write.c:701 [inline]
       do_loop_readv_writev fs/read_write.c:688 [inline]
       do_iter_read+0x4a9/0x660 fs/read_write.c:922
       vfs_readv+0xf0/0x160 fs/read_write.c:984
       kernel_readv fs/splice.c:358 [inline]
       default_file_splice_read+0x475/0x890 fs/splice.c:413
       do_splice_to+0x12a/0x190 fs/splice.c:876
       splice_direct_to_actor+0x2d2/0x970 fs/splice.c:953
       do_splice_direct+0x1da/0x2a0 fs/splice.c:1062
       do_sendfile+0x597/0xd00 fs/read_write.c:1443
       __do_sys_sendfile64 fs/read_write.c:1498 [inline]
       __se_sys_sendfile64 fs/read_write.c:1490 [inline]
       __x64_sys_sendfile64+0x15a/0x220 fs/read_write.c:1490
       do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe
      RIP: 0033:0x458da9
      Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
      RSP: 002b:00007f300d24bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
      RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000458da9
      RDX: 00000000200000c0 RSI: 0000000000000008 RDI: 0000000000000007
      RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
      R10: 000000000000005a R11: 0000000000000246 R12: 00007f300d24c6d4
      R13: 00000000004c5fa3 R14: 00000000004da748 R15: 00000000ffffffff
      
      Allocated by task 17543:
       save_stack+0x45/0xd0 mm/kasan/common.c:75
       set_track mm/kasan/common.c:87 [inline]
       __kasan_kmalloc mm/kasan/common.c:497 [inline]
       __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470
       kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:505
       slab_post_alloc_hook mm/slab.h:437 [inline]
       slab_alloc mm/slab.c:3393 [inline]
       kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3555
       alloc_pid+0x55/0x8f0 kernel/pid.c:168
       copy_process.part.0+0x3b08/0x7980 kernel/fork.c:1932
       copy_process kernel/fork.c:1709 [inline]
       _do_fork+0x257/0xfd0 kernel/fork.c:2226
       __do_sys_clone kernel/fork.c:2333 [inline]
       __se_sys_clone kernel/fork.c:2327 [inline]
       __x64_sys_clone+0xbf/0x150 kernel/fork.c:2327
       do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe
      
      Freed by task 7789:
       save_stack+0x45/0xd0 mm/kasan/common.c:75
       set_track mm/kasan/common.c:87 [inline]
       __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459
       kasan_slab_free+0xe/0x10 mm/kasan/common.c:467
       __cache_free mm/slab.c:3499 [inline]
       kmem_cache_free+0x86/0x260 mm/slab.c:3765
       put_pid.part.0+0x111/0x150 kernel/pid.c:111
       put_pid+0x20/0x30 kernel/pid.c:105
       fl_free+0xbe/0xe0 net/ipv6/ip6_flowlabel.c:102
       ip6_fl_gc+0x295/0x3e0 net/ipv6/ip6_flowlabel.c:152
       call_timer_fn+0x190/0x720 kernel/time/timer.c:1325
       expire_timers kernel/time/timer.c:1362 [inline]
       __run_timers kernel/time/timer.c:1681 [inline]
       __run_timers kernel/time/timer.c:1649 [inline]
       run_timer_softirq+0x652/0x1700 kernel/time/timer.c:1694
       __do_softirq+0x266/0x95a kernel/softirq.c:293
      
      The buggy address belongs to the object at ffff888094012a00
       which belongs to the cache pid_2 of size 88
      The buggy address is located 4 bytes inside of
       88-byte region [ffff888094012a00, ffff888094012a58)
      The buggy address belongs to the page:
      page:ffffea0002500480 count:1 mapcount:0 mapping:ffff88809a483080 index:0xffff888094012980
      flags: 0x1fffc0000000200(slab)
      raw: 01fffc0000000200 ffffea00018a3508 ffffea0002524a88 ffff88809a483080
      raw: ffff888094012980 ffff888094012000 000000010000001b 0000000000000000
      page dumped because: kasan: bad access detected
      
      Memory state around the buggy address:
       ffff888094012900: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
       ffff888094012980: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
      >ffff888094012a00: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
                         ^
       ffff888094012a80: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
       ffff888094012b00: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
      
      Fixes: 4f82f457 ("net ip6 flowlabel: Make owner a union of struct pid * and kuid_t")
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Reported-by: Nsyzbot <syzkaller@googlegroups.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      39eddbb7
    • E
      ipv6: fix races in ip6_dst_destroy() · 1a9e0134
      Eric Dumazet 提交于
      [ Upstream commit 0e2338749192ce0e52e7174c5352f627632f478a ]
      
      We had many syzbot reports that seem to be caused by use-after-free
      of struct fib6_info.
      
      ip6_dst_destroy(), fib6_drop_pcpu_from() and rt6_remove_exception()
      are writers vs rt->from, and use non consistent synchronization among
      themselves.
      
      Switching to xchg() will solve the issues with no possible
      lockdep issues.
      
      BUG: KASAN: user-memory-access in atomic_dec_and_test include/asm-generic/atomic-instrumented.h:747 [inline]
      BUG: KASAN: user-memory-access in fib6_info_release include/net/ip6_fib.h:294 [inline]
      BUG: KASAN: user-memory-access in fib6_info_release include/net/ip6_fib.h:292 [inline]
      BUG: KASAN: user-memory-access in fib6_drop_pcpu_from net/ipv6/ip6_fib.c:927 [inline]
      BUG: KASAN: user-memory-access in fib6_purge_rt+0x4f6/0x670 net/ipv6/ip6_fib.c:960
      Write of size 4 at addr 0000000000ffffb4 by task syz-executor.1/7649
      
      CPU: 0 PID: 7649 Comm: syz-executor.1 Not tainted 5.1.0-rc6+ #183
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      Call Trace:
       __dump_stack lib/dump_stack.c:77 [inline]
       dump_stack+0x172/0x1f0 lib/dump_stack.c:113
       kasan_report.cold+0x5/0x40 mm/kasan/report.c:321
       check_memory_region_inline mm/kasan/generic.c:185 [inline]
       check_memory_region+0x123/0x190 mm/kasan/generic.c:191
       kasan_check_write+0x14/0x20 mm/kasan/common.c:108
       atomic_dec_and_test include/asm-generic/atomic-instrumented.h:747 [inline]
       fib6_info_release include/net/ip6_fib.h:294 [inline]
       fib6_info_release include/net/ip6_fib.h:292 [inline]
       fib6_drop_pcpu_from net/ipv6/ip6_fib.c:927 [inline]
       fib6_purge_rt+0x4f6/0x670 net/ipv6/ip6_fib.c:960
       fib6_del_route net/ipv6/ip6_fib.c:1813 [inline]
       fib6_del+0xac2/0x10a0 net/ipv6/ip6_fib.c:1844
       fib6_clean_node+0x3a8/0x590 net/ipv6/ip6_fib.c:2006
       fib6_walk_continue+0x495/0x900 net/ipv6/ip6_fib.c:1928
       fib6_walk+0x9d/0x100 net/ipv6/ip6_fib.c:1976
       fib6_clean_tree+0xe0/0x120 net/ipv6/ip6_fib.c:2055
       __fib6_clean_all+0x118/0x2a0 net/ipv6/ip6_fib.c:2071
       fib6_clean_all+0x2b/0x40 net/ipv6/ip6_fib.c:2082
       rt6_sync_down_dev+0x134/0x150 net/ipv6/route.c:4057
       rt6_disable_ip+0x27/0x5f0 net/ipv6/route.c:4062
       addrconf_ifdown+0xa2/0x1220 net/ipv6/addrconf.c:3705
       addrconf_notify+0x19a/0x2260 net/ipv6/addrconf.c:3630
       notifier_call_chain+0xc7/0x240 kernel/notifier.c:93
       __raw_notifier_call_chain kernel/notifier.c:394 [inline]
       raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:401
       call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1753
       call_netdevice_notifiers_extack net/core/dev.c:1765 [inline]
       call_netdevice_notifiers net/core/dev.c:1779 [inline]
       dev_close_many+0x33f/0x6f0 net/core/dev.c:1522
       rollback_registered_many+0x43b/0xfd0 net/core/dev.c:8177
       rollback_registered+0x109/0x1d0 net/core/dev.c:8242
       unregister_netdevice_queue net/core/dev.c:9289 [inline]
       unregister_netdevice_queue+0x1ee/0x2c0 net/core/dev.c:9282
       unregister_netdevice include/linux/netdevice.h:2658 [inline]
       __tun_detach+0xd5b/0x1000 drivers/net/tun.c:727
       tun_detach drivers/net/tun.c:744 [inline]
       tun_chr_close+0xe0/0x180 drivers/net/tun.c:3443
       __fput+0x2e5/0x8d0 fs/file_table.c:278
       ____fput+0x16/0x20 fs/file_table.c:309
       task_work_run+0x14a/0x1c0 kernel/task_work.c:113
       exit_task_work include/linux/task_work.h:22 [inline]
       do_exit+0x90a/0x2fa0 kernel/exit.c:876
       do_group_exit+0x135/0x370 kernel/exit.c:980
       __do_sys_exit_group kernel/exit.c:991 [inline]
       __se_sys_exit_group kernel/exit.c:989 [inline]
       __x64_sys_exit_group+0x44/0x50 kernel/exit.c:989
       do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe
      RIP: 0033:0x458da9
      Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
      RSP: 002b:00007ffeafc2a6a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
      RAX: ffffffffffffffda RBX: 000000000000001c RCX: 0000000000458da9
      RDX: 0000000000412a80 RSI: 0000000000a54ef0 RDI: 0000000000000043
      RBP: 00000000004be552 R08: 000000000000000c R09: 000000000004c0d1
      R10: 0000000002341940 R11: 0000000000000246 R12: 00000000ffffffff
      R13: 00007ffeafc2a7f0 R14: 000000000004c065 R15: 00007ffeafc2a800
      
      Fixes: a68886a6 ("net/ipv6: Make from in rt6_info rcu protected")
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Reported-by: Nsyzbot <syzkaller@googlegroups.com>
      Cc: David Ahern <dsahern@gmail.com>
      Reviewed-by: NDavid Ahern <dsahern@gmail.com>
      Acked-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NWei Wang <weiwan@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1a9e0134
    • M
      ipv6: A few fixes on dereferencing rt->from · 7ea4f000
      Martin KaFai Lau 提交于
      [ Upstream commit 886b7a50100a50f1cbd08a6f8ec5884dfbe082dc ]
      
      It is a followup after the fix in
      commit 9c69a1320515 ("route: Avoid crash from dereferencing NULL rt->from")
      
      rt6_do_redirect():
      1. NULL checking is needed on rt->from because a parallel
         fib6_info delete could happen that sets rt->from to NULL.
         (e.g. rt6_remove_exception() and fib6_drop_pcpu_from()).
      
      2. fib6_info_hold() is not enough.  Same reason as (1).
         Meaning, holding dst->__refcnt cannot ensure
         rt->from is not NULL or rt->from->fib6_ref is not 0.
      
         Instead of using fib6_info_hold_safe() which ip6_rt_cache_alloc()
         is already doing, this patch chooses to extend the rcu section
         to keep "from" dereference-able after checking for NULL.
      
      inet6_rtm_getroute():
      1. NULL checking is also needed on rt->from for a similar reason.
         Note that inet6_rtm_getroute() is using RTNL_FLAG_DOIT_UNLOCKED.
      
      Fixes: a68886a6 ("net/ipv6: Make from in rt6_info rcu protected")
      Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NWei Wang <weiwan@google.com>
      Reviewed-by: NDavid Ahern <dsahern@gmail.com>
      Reviewed-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7ea4f000
    • S
      ipv4: ip_do_fragment: Preserve skb_iif during fragmentation · 3f611a47
      Shmulik Ladkani 提交于
      [ Upstream commit d2f0c961148f65bc73eda72b9fa3a4e80973cb49 ]
      
      Previously, during fragmentation after forwarding, skb->skb_iif isn't
      preserved, i.e. 'ip_copy_metadata' does not copy skb_iif from given
      'from' skb.
      
      As a result, ip_do_fragment's creates fragments with zero skb_iif,
      leading to inconsistent behavior.
      
      Assume for example an eBPF program attached at tc egress (post
      forwarding) that examines __sk_buff->ingress_ifindex:
       - the correct iif is observed if forwarding path does not involve
         fragmentation/refragmentation
       - a bogus iif is observed if forwarding path involves
         fragmentation/refragmentatiom
      
      Fix, by preserving skb_iif during 'ip_copy_metadata'.
      Signed-off-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3f611a47
  2. 04 5月, 2019 35 次提交