• Xin Long's avatar
    tipc: force a dst refcount before doing decryption · 2ebe8f84
    Xin Long authored
    As it says in commit 3bc07321 ("xfrm: Force a dst refcount before
    entering the xfrm type handlers"):
    
    "Crypto requests might return asynchronous. In this case we leave the
     rcu protected region, so force a refcount on the skb's destination
     entry before we enter the xfrm type input/output handlers."
    
    On TIPC decryption path it has the same problem, and skb_dst_force()
    should be called before doing decryption to avoid a possible crash.
    
    Shuang reported this issue when this warning is triggered:
    
      [] WARNING: include/net/dst.h:337 tipc_sk_rcv+0x1055/0x1ea0 [tipc]
      [] Kdump: loaded Tainted: G W --------- - - 4.18.0-496.el8.x86_64+debug
      [] Workqueue: crypto cryptd_queue_worker
      [] RIP: 0010:tipc_sk_rcv+0x1055/0x1ea0 [tipc]
      [] Call Trace:
      [] tipc_sk_mcast_rcv+0x548/0xea0 [tipc]
      [] tipc_rcv+0xcf5/0x1060 [tipc]
      [] tipc_aead_decrypt_done+0x215/0x2e0 [tipc]
      [] cryptd_aead_crypt+0xdb/0x190
      [] cryptd_queue_worker+0xed/0x190
      [] process_one_work+0x93d/0x17e0
    
    Fixes: fc1b6d6d ("tipc: introduce TIPC encryption & authentication")
    Reported-by: default avatarShuang Li <shuali@redhat.com>
    Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
    Link: https://lore.kernel.org/r/fbe3195fad6997a4eec62d9bf076b2ad03ac336b.1718476040.git.lucien.xin@gmail.comSigned-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
    2ebe8f84
node.c 79.1 KB