1. 09 Mar, 2018 38 commits
  2. 03 Mar, 2018 2 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.14.24 · 6e4548ea
      Greg Kroah-Hartman authored
      6e4548ea
    • Jiri Pirko's avatar
      net: sched: fix use-after-free in tcf_block_put_ext · ab5d9d17
      Jiri Pirko authored
      commit df45bf84 upstream.
      
      Since the block is freed with last chain being put, once we reach the
      end of iteration of list_for_each_entry_safe, the block may be
      already freed. I'm hitting this only by creating and deleting clsact:
      
      [  202.171952] ==================================================================
      [  202.180182] BUG: KASAN: use-after-free in tcf_block_put_ext+0x240/0x390
      [  202.187590] Read of size 8 at addr ffff880225539a80 by task tc/796
      [  202.194508]
      [  202.196185] CPU: 0 PID: 796 Comm: tc Not tainted 4.15.0-rc2jiri+ #5
      [  202.203200] Hardware name: Mellanox Technologies Ltd. "MSN2100-CB2F"/"SA001017", BIOS 5.6.5 06/07/2016
      [  202.213613] Call Trace:
      [  202.216369]  dump_stack+0xda/0x169
      [  202.220192]  ? dma_virt_map_sg+0x147/0x147
      [  202.224790]  ? show_regs_print_info+0x54/0x54
      [  202.229691]  ? tcf_chain_destroy+0x1dc/0x250
      [  202.234494]  print_address_description+0x83/0x3d0
      [  202.239781]  ? tcf_block_put_ext+0x240/0x390
      [  202.244575]  kasan_report+0x1ba/0x460
      [  202.248707]  ? tcf_block_put_ext+0x240/0x390
      [  202.253518]  tcf_block_put_ext+0x240/0x390
      [  202.258117]  ? tcf_chain_flush+0x290/0x290
      [  202.262708]  ? qdisc_hash_del+0x82/0x1a0
      [  202.267111]  ? qdisc_hash_add+0x50/0x50
      [  202.271411]  ? __lock_is_held+0x5f/0x1a0
      [  202.275843]  clsact_destroy+0x3d/0x80 [sch_ingress]
      [  202.281323]  qdisc_destroy+0xcb/0x240
      [  202.285445]  qdisc_graft+0x216/0x7b0
      [  202.289497]  tc_get_qdisc+0x260/0x560
      
      Fix this by holding the block also by chain 0 and put chain 0
      explicitly, out of the list_for_each_entry_safe loop at the very
      end of tcf_block_put_ext.
      
      Fixes: efbf7897 ("net_sched: get rid of rcu_barrier() in tcf_block_put_ext()")
      Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Cc: Cong Wang <xiyou.wangcong@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      
      ab5d9d17