1. 25 Jan, 2024 1 commit
    • Lin Ma's avatar
      ksmbd: fix global oob in ksmbd_nl_policy · ebeae8ad
      Lin Ma authored
      Similar to a reported issue (check the commit b33fb5b8 ("net:
      qualcomm: rmnet: fix global oob in rmnet_policy"), my local fuzzer finds
      another global out-of-bounds read for policy ksmbd_nl_policy. See bug
      trace below:
      
      ==================================================================
      BUG: KASAN: global-out-of-bounds in validate_nla lib/nlattr.c:386 [inline]
      BUG: KASAN: global-out-of-bounds in __nla_validate_parse+0x24af/0x2750 lib/nlattr.c:600
      Read of size 1 at addr ffffffff8f24b100 by task syz-executor.1/62810
      
      CPU: 0 PID: 62810 Comm: syz-executor.1 Tainted: G                 N 6.1.0 #3
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
      Call Trace:
       <TASK>
       __dump_stack lib/dump_stack.c:88 [inline]
       dump_stack_lvl+0x8b/0xb3 lib/dump_stack.c:106
       print_address_description mm/kasan/report.c:284 [inline]
       print_report+0x172/0x475 mm/kasan/report.c:395
       kasan_report+0xbb/0x1c0 mm/kasan/report.c:495
       validate_nla lib/nlattr.c:386 [inline]
       __nla_validate_parse+0x24af/0x2750 lib/nlattr.c:600
       __nla_parse+0x3e/0x50 lib/nlattr.c:697
       __nlmsg_parse include/net/netlink.h:748 [inline]
       genl_family_rcv_msg_attrs_parse.constprop.0+0x1b0/0x290 net/netlink/genetlink.c:565
       genl_family_rcv_msg_doit+0xda/0x330 net/netlink/genetlink.c:734
       genl_family_rcv_msg net/netlink/genetlink.c:833 [inline]
       genl_rcv_msg+0x441/0x780 net/netlink/genetlink.c:850
       netlink_rcv_skb+0x14f/0x410 net/netlink/af_netlink.c:2540
       genl_rcv+0x24/0x40 net/netlink/genetlink.c:861
       netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
       netlink_unicast+0x54e/0x800 net/netlink/af_netlink.c:1345
       netlink_sendmsg+0x930/0xe50 net/netlink/af_netlink.c:1921
       sock_sendmsg_nosec net/socket.c:714 [inline]
       sock_sendmsg+0x154/0x190 net/socket.c:734
       ____sys_sendmsg+0x6df/0x840 net/socket.c:2482
       ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
       __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd
      RIP: 0033:0x7fdd66a8f359
      Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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:00007fdd65e00168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
      RAX: ffffffffffffffda RBX: 00007fdd66bbcf80 RCX: 00007fdd66a8f359
      RDX: 0000000000000000 RSI: 0000000020000500 RDI: 0000000000000003
      RBP: 00007fdd66ada493 R08: 0000000000000000 R09: 0000000000000000
      R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
      R13: 00007ffc84b81aff R14: 00007fdd65e00300 R15: 0000000000022000
       </TASK>
      
      The buggy address belongs to the variable:
       ksmbd_nl_policy+0x100/0xa80
      
      The buggy address belongs to the physical page:
      page:0000000034f47940 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1ccc4b
      flags: 0x200000000001000(reserved|node=0|zone=2)
      raw: 0200000000001000 ffffea00073312c8 ffffea00073312c8 0000000000000000
      raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
      page dumped because: kasan: bad access detected
      
      Memory state around the buggy address:
       ffffffff8f24b000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
       ffffffff8f24b080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
      >ffffffff8f24b100: f9 f9 f9 f9 00 00 f9 f9 f9 f9 f9 f9 00 00 07 f9
                         ^
       ffffffff8f24b180: f9 f9 f9 f9 00 05 f9 f9 f9 f9 f9 f9 00 00 00 05
       ffffffff8f24b200: f9 f9 f9 f9 00 00 03 f9 f9 f9 f9 f9 00 00 04 f9
      ==================================================================
      
      To fix it, add a placeholder named __KSMBD_EVENT_MAX and let
      KSMBD_EVENT_MAX to be its original value - 1 according to what other
      netlink families do. Also change two sites that refer the
      KSMBD_EVENT_MAX to correct value.
      
      Cc: stable@vger.kernel.org
      Fixes: 0626e664 ("cifsd: add server handler for central processing and tranport layers")
      Signed-off-by: default avatarLin Ma <linma@zju.edu.cn>
      Acked-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
      Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
      ebeae8ad
  2. 21 Jan, 2024 39 commits