• Eric Dumazet's avatar
    nfc: llcp: fix nfc_llcp_setsockopt() unsafe copies · 7a87441c
    Eric Dumazet authored
    syzbot reported unsafe calls to copy_from_sockptr() [1]
    
    Use copy_safe_from_sockptr() instead.
    
    [1]
    
    BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset include/linux/sockptr.h:49 [inline]
     BUG: KASAN: slab-out-of-bounds in copy_from_sockptr include/linux/sockptr.h:55 [inline]
     BUG: KASAN: slab-out-of-bounds in nfc_llcp_setsockopt+0x6c2/0x850 net/nfc/llcp_sock.c:255
    Read of size 4 at addr ffff88801caa1ec3 by task syz-executor459/5078
    
    CPU: 0 PID: 5078 Comm: syz-executor459 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd #0
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
    Call Trace:
     <TASK>
      __dump_stack lib/dump_stack.c:88 [inline]
      dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
      print_address_description mm/kasan/report.c:377 [inline]
      print_report+0x169/0x550 mm/kasan/report.c:488
      kasan_report+0x143/0x180 mm/kasan/report.c:601
      copy_from_sockptr_offset include/linux/sockptr.h:49 [inline]
      copy_from_sockptr include/linux/sockptr.h:55 [inline]
      nfc_llcp_setsockopt+0x6c2/0x850 net/nfc/llcp_sock.c:255
      do_sock_setsockopt+0x3b1/0x720 net/socket.c:2311
      __sys_setsockopt+0x1ae/0x250 net/socket.c:2334
      __do_sys_setsockopt net/socket.c:2343 [inline]
      __se_sys_setsockopt net/socket.c:2340 [inline]
      __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340
     do_syscall_64+0xfd/0x240
     entry_SYSCALL_64_after_hwframe+0x6d/0x75
    RIP: 0033:0x7f7fac07fd89
    Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 91 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
    RSP: 002b:00007fff660eb788 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
    RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f7fac07fd89
    RDX: 0000000000000000 RSI: 0000000000000118 RDI: 0000000000000004
    RBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000000000
    R10: 0000000020000a80 R11: 0000000000000246 R12: 0000000000000000
    R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
    Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
    Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
    Reviewed-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
    Link: https://lore.kernel.org/r/20240408082845.3957374-4-edumazet@google.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
    7a87441c
llcp_sock.c 22.3 KB