From: William Liu will@willsroot.io
commit 797805d81baa814f76cf7bdab35f86408a79d707 upstream.
"nt_len - CIFS_ENCPWD_SIZE" is passed directly from ksmbd_decode_ntlmssp_auth_blob to ksmbd_auth_ntlmv2. Malicious requests can set nt_len to less than CIFS_ENCPWD_SIZE, which results in a negative number (or large unsigned value) used for a subsequent memcpy in ksmbd_auth_ntlvm2 and can cause a panic.
Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Signed-off-by: William Liu will@willsroot.io Signed-off-by: Hrvoje Mišetić misetichrvoje@gmail.com Acked-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ksmbd/auth.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/ksmbd/auth.c +++ b/fs/ksmbd/auth.c @@ -319,7 +319,8 @@ int ksmbd_decode_ntlmssp_auth_blob(struc dn_off = le32_to_cpu(authblob->DomainName.BufferOffset); dn_len = le16_to_cpu(authblob->DomainName.Length);
- if (blob_len < (u64)dn_off + dn_len || blob_len < (u64)nt_off + nt_len) + if (blob_len < (u64)dn_off + dn_len || blob_len < (u64)nt_off + nt_len || + nt_len < CIFS_ENCPWD_SIZE) return -EINVAL;
/* TODO : use domain name that imported from configuration file */