1. 01 Dec, 2022 1 commit
    • Pengcheng Yang's avatar
      bpf, sockmap: Fix repeated calls to sock_put() when msg has more_data · 7a9841ca
      Pengcheng Yang authored
      In tcp_bpf_send_verdict() redirection, the eval variable is assigned to
      __SK_REDIRECT after the apply_bytes data is sent, if msg has more_data,
      sock_put() will be called multiple times.
      
      We should reset the eval variable to __SK_NONE every time more_data
      starts.
      
      This causes:
      
      IPv4: Attempt to release TCP socket in state 1 00000000b4c925d7
      ------------[ cut here ]------------
      refcount_t: addition on 0; use-after-free.
      WARNING: CPU: 5 PID: 4482 at lib/refcount.c:25 refcount_warn_saturate+0x7d/0x110
      Modules linked in:
      CPU: 5 PID: 4482 Comm: sockhash_bypass Kdump: loaded Not tainted 6.0.0 #1
      Hardware name: Red Hat KVM, BIOS 1.11.0-2.el7 04/01/2014
      Call Trace:
       <TASK>
       __tcp_transmit_skb+0xa1b/0xb90
       ? __alloc_skb+0x8c/0x1a0
       ? __kmalloc_node_track_caller+0x184/0x320
       tcp_write_xmit+0x22a/0x1110
       __tcp_push_pending_frames+0x32/0xf0
       do_tcp_sendpages+0x62d/0x640
       tcp_bpf_push+0xae/0x2c0
       tcp_bpf_sendmsg_redir+0x260/0x410
       ? preempt_count_add+0x70/0xa0
       tcp_bpf_send_verdict+0x386/0x4b0
       tcp_bpf_sendmsg+0x21b/0x3b0
       sock_sendmsg+0x58/0x70
       __sys_sendto+0xfa/0x170
       ? xfd_validate_state+0x1d/0x80
       ? switch_fpu_return+0x59/0xe0
       __x64_sys_sendto+0x24/0x30
       do_syscall_64+0x37/0x90
       entry_SYSCALL_64_after_hwframe+0x63/0xcd
      
      Fixes: cd9733f5 ("tcp_bpf: Fix one concurrency problem in the tcp_bpf_send_verdict function")
      Signed-off-by: default avatarPengcheng Yang <yangpc@wangsu.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: default avatarJakub Sitnicki <jakub@cloudflare.com>
      Link: https://lore.kernel.org/bpf/1669718441-2654-2-git-send-email-yangpc@wangsu.com
      7a9841ca
  2. 30 Nov, 2022 26 commits
  3. 29 Nov, 2022 13 commits