1. 30 Aug, 2017 1 commit
    • Eric Dumazet's avatar
      af_key: do not use GFP_KERNEL in atomic contexts · f0cd9201
      Eric Dumazet authored
      
      [ Upstream commit 36f41f8f ]
      
      pfkey_broadcast() might be called from non process contexts,
      we can not use GFP_KERNEL in these cases [1].
      
      This patch partially reverts commit ba51b6be ("net: Fix RCU splat in
      af_key"), only keeping the GFP_ATOMIC forcing under rcu_read_lock()
      section.
      
      [1] : syzkaller reported :
      
      in_atomic(): 1, irqs_disabled(): 0, pid: 2932, name: syzkaller183439
      3 locks held by syzkaller183439/2932:
       #0:  (&net->xfrm.xfrm_cfg_mutex){+.+.+.}, at: [<ffffffff83b43888>] pfkey_sendmsg+0x4c8/0x9f0 net/key/af_key.c:3649
       #1:  (&pfk->dump_lock){+.+.+.}, at: [<ffffffff83b467f6>] pfkey_do_dump+0x76/0x3f0 net/key/af_key.c:293
       #2:  (&(&net->xfrm.xfrm_policy_lock)->rlock){+...+.}, at: [<ffffffff83957632>] spin_lock_bh include/linux/spinlock.h:304 [inline]
       #2:  (&(&net->xfrm.xfrm_policy_lock)->rlock){+...+.}, at: [<ffffffff83957632>] xfrm_policy_walk+0x192/0xa30 net/xfrm/xfrm_policy.c:1028
      CPU: 0 PID: 2932 Comm: syzkaller183439 Not tainted 4.13.0-rc4+ #24
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      Call Trace:
       __dump_stack lib/dump_stack.c:16 [inline]
       dump_stack+0x194/0x257 lib/dump_stack.c:52
       ___might_sleep+0x2b2/0x470 kernel/sched/core.c:5994
       __might_sleep+0x95/0x190 kernel/sched/core.c:5947
       slab_pre_alloc_hook mm/slab.h:416 [inline]
       slab_alloc mm/slab.c:3383 [inline]
       kmem_cache_alloc+0x24b/0x6e0 mm/slab.c:3559
       skb_clone+0x1a0/0x400 net/core/skbuff.c:1037
       pfkey_broadcast_one+0x4b2/0x6f0 net/key/af_key.c:207
       pfkey_broadcast+0x4ba/0x770 net/key/af_key.c:281
       dump_sp+0x3d6/0x500 net/key/af_key.c:2685
       xfrm_policy_walk+0x2f1/0xa30 net/xfrm/xfrm_policy.c:1042
       pfkey_dump_sp+0x42/0x50 net/key/af_key.c:2695
       pfkey_do_dump+0xaa/0x3f0 net/key/af_key.c:299
       pfkey_spddump+0x1a0/0x210 net/key/af_key.c:2722
       pfkey_process+0x606/0x710 net/key/af_key.c:2814
       pfkey_sendmsg+0x4d6/0x9f0 net/key/af_key.c:3650
      sock_sendmsg_nosec net/socket.c:633 [inline]
       sock_sendmsg+0xca/0x110 net/socket.c:643
       ___sys_sendmsg+0x755/0x890 net/socket.c:2035
       __sys_sendmsg+0xe5/0x210 net/socket.c:2069
       SYSC_sendmsg net/socket.c:2080 [inline]
       SyS_sendmsg+0x2d/0x50 net/socket.c:2076
       entry_SYSCALL_64_fastpath+0x1f/0xbe
      RIP: 0033:0x445d79
      RSP: 002b:00007f32447c1dc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
      RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000445d79
      RDX: 0000000000000000 RSI: 000000002023dfc8 RDI: 0000000000000008
      RBP: 0000000000000086 R08: 00007f32447c2700 R09: 00007f32447c2700
      R10: 00007f32447c2700 R11: 0000000000000202 R12: 0000000000000000
      R13: 00007ffe33edec4f R14: 00007f32447c29c0 R15: 0000000000000000
      
      Fixes: ba51b6be ("net: Fix RCU splat in af_key")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: David Ahern <dsa@cumulusnetworks.com>
      Acked-by: default avatarDavid Ahern <dsahern@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f0cd9201
  2. 25 Aug, 2017 21 commits
  3. 16 Aug, 2017 18 commits