• Leon Romanovsky's avatar
    net: sched: Fix suspicious RCU usage while accessing tcf_tunnel_info · d086a1c6
    Leon Romanovsky authored
    The access of tcf_tunnel_info() produces the following splat, so fix it
    by dereferencing the tcf_tunnel_key_params pointer with marker that
    internal tcfa_liock is held.
    
     =============================
     WARNING: suspicious RCU usage
     5.9.0+ #1 Not tainted
     -----------------------------
     include/net/tc_act/tc_tunnel_key.h:59 suspicious rcu_dereference_protected() usage!
     other info that might help us debug this:
    
     rcu_scheduler_active = 2, debug_locks = 1
     1 lock held by tc/34839:
      #0: ffff88828572c2a0 (&p->tcfa_lock){+...}-{2:2}, at: tc_setup_flow_action+0xb3/0x48b5
     stack backtrace:
     CPU: 1 PID: 34839 Comm: tc Not tainted 5.9.0+ #1
     Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
     Call Trace:
      dump_stack+0x9a/0xd0
      tc_setup_flow_action+0x14cb/0x48b5
      fl_hw_replace_filter+0x347/0x690 [cls_flower]
      fl_change+0x2bad/0x4875 [cls_flower]
      tc_new_tfilter+0xf6f/0x1ba0
      rtnetlink_rcv_msg+0x5f2/0x870
      netlink_rcv_skb+0x124/0x350
      netlink_unicast+0x433/0x700
      netlink_sendmsg+0x6f1/0xbd0
      sock_sendmsg+0xb0/0xe0
      ____sys_sendmsg+0x4fa/0x6d0
      ___sys_sendmsg+0x12e/0x1b0
      __sys_sendmsg+0xa4/0x120
      do_syscall_64+0x2d/0x40
      entry_SYSCALL_64_after_hwframe+0x44/0xa9
     RIP: 0033:0x7f1f8cd4fe57
     Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
     RSP: 002b:00007ffdc1e193b8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
     RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1f8cd4fe57
     RDX: 0000000000000000 RSI: 00007ffdc1e19420 RDI: 0000000000000003
     RBP: 000000005f85aafa R08: 0000000000000001 R09: 00007ffdc1e1936c
     R10: 000000000040522d R11: 0000000000000246 R12: 0000000000000001
     R13: 0000000000000000 R14: 00007ffdc1e1d6f0 R15: 0000000000482420
    
    Fixes: 3ebaf6da ("net: sched: Do not assume RTNL is held in tunnel key action helpers")
    Fixes: 7a472814 ("net: sched: lock action when translating it to flow_action infra")
    Signed-off-by: default avatarLeon Romanovsky <leonro@nvidia.com>
    Acked-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
    Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
    d086a1c6
tc_tunnel_key.h 2.11 KB