[PATCH 5.13 07/35] cifs: use helpers when parsing uid/gid mount options and validate them

Greg Kroah-Hartman
2021-08-06T08:24:53Z

From: Ronnie Sahlberg <lsahlber@redhat.com>

[ Upstream commit e0a3cbcd5cef00cace01546cc6eaaa3b31940da9 ]

Use the nice helpers to initialize and the uid/gid/cred_uid when passed as mount arguments.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Acked-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/cifs/fs_context.c | 24 +++++++++++++++++++-----
fs/cifs/fs_context.h | 1 +
2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c
index 92d4ab029c91..553adfbcc22a 100644
--- a/fs/cifs/fs_context.c
+++ b/fs/cifs/fs_context.c
@@ -322,7 +322,6 @@ smb3_fs_context_dup(struct smb3_fs_context *new_ctx, struct smb3_fs_context *ctx
new_ctx->UNC = NULL;
new_ctx->source = NULL;
new_ctx->iocharset = NULL;
-
/*
* Make sure to stay in sync with smb3_cleanup_fs_context_contents()
*/
@@ -792,6 +791,8 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
int i, opt;
bool is_smb3 = !strcmp(fc->fs_type->name, "smb3");
bool skip_parsing = false;
+ kuid_t uid;
+ kgid_t gid;

cifs_dbg(FYI, "CIFS: parsing cifs mount option '%s'\n", param->key);

@@ -904,18 +905,31 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
}
break;
case Opt_uid:
- ctx->linux_uid.val = result.uint_32;
+ uid = make_kuid(current_user_ns(), result.uint_32);
+ if (!uid_valid(uid))
+ goto cifs_parse_mount_err;
+ ctx->linux_uid = uid;
ctx->uid_specified = true;
break;
case Opt_cruid:
- ctx->cred_uid.val = result.uint_32;
+ uid = make_kuid(current_user_ns(), result.uint_32);
+ if (!uid_valid(uid))
+ goto cifs_parse_mount_err;
+ ctx->cred_uid = uid;
+ ctx->cruid_specified = true;
break;
case Opt_backupgid:
- ctx->backupgid.val = result.uint_32;
+ gid = make_kgid(current_user_ns(), result.uint_32);
+ if (!gid_valid(gid))
+ goto cifs_parse_mount_err;
+ ctx->backupgid = gid;
ctx->backupgid_specified = true;
break;
case Opt_gid:
- ctx->linux_gid.val = result.uint_32;
+ gid = make_kgid(current_user_ns(), result.uint_32);
+ if (!gid_valid(gid))
+ goto cifs_parse_mount_err;
+ ctx->linux_gid = gid;
ctx->gid_specified = true;
break;
case Opt_port:
diff --git a/fs/cifs/fs_context.h b/fs/cifs/fs_context.h
index 2a71c8e411ac..b6243972edf3 100644
--- a/fs/cifs/fs_context.h
+++ b/fs/cifs/fs_context.h
@@ -155,6 +155,7 @@ enum cifs_param {

struct smb3_fs_context {
bool uid_specified;
+ bool cruid_specified;
bool gid_specified;
bool sloppy;
bool got_ip;
--
2.30.2