1. 22 Nov, 2022 1 commit
  2. 21 Nov, 2022 30 commits
  3. 19 Nov, 2022 8 commits
  4. 18 Nov, 2022 1 commit
    • Schspa Shi's avatar
      mrp: introduce active flags to prevent UAF when applicant uninit · ab037780
      Schspa Shi authored
      The caller of del_timer_sync must prevent restarting of the timer, If
      we have no this synchronization, there is a small probability that the
      cancellation will not be successful.
      
      And syzbot report the fellowing crash:
      ==================================================================
      BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:929 [inline]
      BUG: KASAN: use-after-free in enqueue_timer+0x18/0xa4 kernel/time/timer.c:605
      Write at addr f9ff000024df6058 by task syz-fuzzer/2256
      Pointer tag: [f9], memory tag: [fe]
      
      CPU: 1 PID: 2256 Comm: syz-fuzzer Not tainted 6.1.0-rc5-syzkaller-00008-
      ge01d50cb #0
      Hardware name: linux,dummy-virt (DT)
      Call trace:
       dump_backtrace.part.0+0xe0/0xf0 arch/arm64/kernel/stacktrace.c:156
       dump_backtrace arch/arm64/kernel/stacktrace.c:162 [inline]
       show_stack+0x18/0x40 arch/arm64/kernel/stacktrace.c:163
       __dump_stack lib/dump_stack.c:88 [inline]
       dump_stack_lvl+0x68/0x84 lib/dump_stack.c:106
       print_address_description mm/kasan/report.c:284 [inline]
       print_report+0x1a8/0x4a0 mm/kasan/report.c:395
       kasan_report+0x94/0xb4 mm/kasan/report.c:495
       __do_kernel_fault+0x164/0x1e0 arch/arm64/mm/fault.c:320
       do_bad_area arch/arm64/mm/fault.c:473 [inline]
       do_tag_check_fault+0x78/0x8c arch/arm64/mm/fault.c:749
       do_mem_abort+0x44/0x94 arch/arm64/mm/fault.c:825
       el1_abort+0x40/0x60 arch/arm64/kernel/entry-common.c:367
       el1h_64_sync_handler+0xd8/0xe4 arch/arm64/kernel/entry-common.c:427
       el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:576
       hlist_add_head include/linux/list.h:929 [inline]
       enqueue_timer+0x18/0xa4 kernel/time/timer.c:605
       mod_timer+0x14/0x20 kernel/time/timer.c:1161
       mrp_periodic_timer_arm net/802/mrp.c:614 [inline]
       mrp_periodic_timer+0xa0/0xc0 net/802/mrp.c:627
       call_timer_fn.constprop.0+0x24/0x80 kernel/time/timer.c:1474
       expire_timers+0x98/0xc4 kernel/time/timer.c:1519
      
      To fix it, we can introduce a new active flags to make sure the timer will
      not restart.
      
      Reported-by: syzbot+6fd64001c20aa99e34a4@syzkaller.appspotmail.com
      Signed-off-by: default avatarSchspa Shi <schspa@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      ab037780