• Will Shiu's avatar
    locks: fix KASAN: use-after-free in trace_event_raw_event_filelock_lock · 74f6f591
    Will Shiu authored
    As following backtrace, the struct file_lock request , in posix_lock_inode
    is free before ftrace function using.
    Replace the ftrace function ahead free flow could fix the use-after-free
    issue.
    
    [name:report&]===============================================
    BUG:KASAN: use-after-free in trace_event_raw_event_filelock_lock+0x80/0x12c
    [name:report&]Read at addr f6ffff8025622620 by task NativeThread/16753
    [name:report_hw_tags&]Pointer tag: [f6], memory tag: [fe]
    [name:report&]
    BT:
    Hardware name: MT6897 (DT)
    Call trace:
     dump_backtrace+0xf8/0x148
     show_stack+0x18/0x24
     dump_stack_lvl+0x60/0x7c
     print_report+0x2c8/0xa08
     kasan_report+0xb0/0x120
     __do_kernel_fault+0xc8/0x248
     do_bad_area+0x30/0xdc
     do_tag_check_fault+0x1c/0x30
     do_mem_abort+0x58/0xbc
     el1_abort+0x3c/0x5c
     el1h_64_sync_handler+0x54/0x90
     el1h_64_sync+0x68/0x6c
     trace_event_raw_event_filelock_lock+0x80/0x12c
     posix_lock_inode+0xd0c/0xd60
     do_lock_file_wait+0xb8/0x190
     fcntl_setlk+0x2d8/0x440
    ...
    [name:report&]
    [name:report&]Allocated by task 16752:
    ...
     slab_post_alloc_hook+0x74/0x340
     kmem_cache_alloc+0x1b0/0x2f0
     posix_lock_inode+0xb0/0xd60
    ...
     [name:report&]
     [name:report&]Freed by task 16752:
    ...
      kmem_cache_free+0x274/0x5b0
      locks_dispose_list+0x3c/0x148
      posix_lock_inode+0xc40/0xd60
      do_lock_file_wait+0xb8/0x190
      fcntl_setlk+0x2d8/0x440
      do_fcntl+0x150/0xc18
    ...
    Signed-off-by: default avatarWill Shiu <Will.Shiu@mediatek.com>
    Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
    74f6f591
locks.c 75.9 KB