diff options
| author | Steve French <stfrench@microsoft.com> | 2018-06-19 22:34:08 +0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2018-08-07 22:15:41 +0300 |
| commit | 7420451f6a109f7f8f1bf283f34d08eba3259fb3 (patch) | |
| tree | cdaf7f33cae4b08c32c6d6baae5dfa0dcfe32121 /fs/cifs | |
| parent | 8505c8bfd85a260c9dc5c47e15bd8c5357fcbcd2 (diff) | |
| download | linux-7420451f6a109f7f8f1bf283f34d08eba3259fb3.tar.xz | |
cifs: allow disabling insecure dialects in the config
allow disabling cifs (SMB1 ie vers=1.0) and vers=2.0 in the
config for the build of cifs.ko if want to always prevent mounting
with these less secure dialects.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Jeremy Allison <jra@samba.org>
Diffstat (limited to 'fs/cifs')
| -rw-r--r-- | fs/cifs/Kconfig | 17 | ||||
| -rw-r--r-- | fs/cifs/connect.c | 9 |
2 files changed, 25 insertions, 1 deletions
diff --git a/fs/cifs/Kconfig b/fs/cifs/Kconfig index 5f132d59dfc2..832eafbf803f 100644 --- a/fs/cifs/Kconfig +++ b/fs/cifs/Kconfig @@ -66,9 +66,24 @@ config CIFS_STATS2 Unless you are a developer or are doing network performance analysis or tuning, say N. +config CIFS_ALLOW_INSECURE_LEGACY + bool "Support legacy servers which use less secure dialects" + depends on CIFS + default y + help + Modern dialects, SMB2.1 and later (including SMB3 and 3.1.1), have + additional security features, including protection against + man-in-the-middle attacks and stronger crypto hashes, so the use + of legacy dialects (SMB1/CIFS and SMB2.0) is discouraged. + + Disabling this option prevents users from using vers=1.0 or vers=2.0 + on mounts with cifs.ko + + If unsure, say Y. + config CIFS_WEAK_PW_HASH bool "Support legacy servers which use weaker LANMAN security" - depends on CIFS + depends on CIFS && CIFS_ALLOW_INSECURE_LEGACY help Modern CIFS servers including Samba and most Windows versions (since 1997) support stronger NTLM (and even NTLMv2 and Kerberos) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 9d02563b2147..842f45859968 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1174,6 +1174,7 @@ cifs_parse_smb_version(char *value, struct smb_vol *vol, bool is_smb3) substring_t args[MAX_OPT_ARGS]; switch (match_token(value, cifs_smb_version_tokens, args)) { +#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY case Smb_1: if (disable_legacy_dialects) { cifs_dbg(VFS, "mount with legacy dialect disabled\n"); @@ -1198,6 +1199,14 @@ cifs_parse_smb_version(char *value, struct smb_vol *vol, bool is_smb3) vol->ops = &smb20_operations; vol->vals = &smb20_values; break; +#else + case Smb_1: + cifs_dbg(VFS, "vers=1.0 (cifs) mount not permitted when legacy dialects disabled\n"); + return 1; + case Smb_20: + cifs_dbg(VFS, "vers=2.0 mount not permitted when legacy dialects disabled\n"); + return 1; +#endif /* CIFS_ALLOW_INSECURE_LEGACY */ case Smb_21: vol->ops = &smb21_operations; vol->vals = &smb21_values; |