package/kernel/ksmbd/patches/10-ksmbd-check-nt_len-to-be-at-least-CIFS_ENCPWD_SIZE-i.patch

   1 From 8824b7af409f51f1316e92e9887c2fd48c0b26d6 Mon Sep 17 00:00:00 2001
   2 From: William Liu <will@willsroot.io>
   3 Date: Fri, 30 Dec 2022 09:13:35 +0900
   4 Subject: ksmbd: check nt_len to be at least CIFS_ENCPWD_SIZE in
   5  ksmbd_decode_ntlmssp_auth_blob
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   9
  10 "nt_len - CIFS_ENCPWD_SIZE" is passed directly from
  11 ksmbd_decode_ntlmssp_auth_blob to ksmbd_auth_ntlmv2. Malicious requests
  12 can set nt_len to less than CIFS_ENCPWD_SIZE, which results in a negative
  13 number (or large unsigned value) used for a subsequent memcpy in
  14 ksmbd_auth_ntlvm2 and can cause a panic.
  15
  16 Fixes: e2f3448 ("cifsd: add server-side procedures for SMB3")
  17 Cc: stable@vger.kernel.org
  18 Signed-off-by: William Liu <will@willsroot.io>
  19 Signed-off-by: Hrvoje Mišetić <misetichrvoje@gmail.com>
  20 Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
  21 ---
  22  auth.c | 3 ++-
  23  1 file changed, 2 insertions(+), 1 deletion(-)
  24
  25 --- a/auth.c
  26 +++ b/auth.c
  27 @@ -583,7 +583,8 @@ int ksmbd_decode_ntlmssp_auth_blob(struc
  28         dn_off = le32_to_cpu(authblob->DomainName.BufferOffset);
  29         dn_len = le16_to_cpu(authblob->DomainName.Length);
  30
  31 -       if (blob_len < (u64)dn_off + dn_len || blob_len < (u64)nt_off + nt_len)
  32 +       if (blob_len < (u64)dn_off + dn_len || blob_len < (u64)nt_off + nt_len ||
  33 +           nt_len < CIFS_ENCPWD_SIZE)
  34                 return -EINVAL;
  35
  36  #ifdef CONFIG_SMB_INSECURE_SERVER