From: Namjae Jeon linkinjeon@kernel.org
[ Upstream commit a018c1b636e79b60149b41151ded7c2606d8606e ]
Sangsoo reported that a DAC denial error occurred when accessing files through the ksmbd thread. This patch override fsids for share path check.
Reported-by: Sangsoo Lee constant.lee@samsung.com Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/smb/server/mgmt/share_config.c | 15 ++++++++++++--- fs/smb/server/mgmt/share_config.h | 4 +++- fs/smb/server/mgmt/tree_connect.c | 9 +++++---- fs/smb/server/mgmt/tree_connect.h | 4 ++-- fs/smb/server/smb2pdu.c | 2 +- fs/smb/server/smb_common.c | 9 +++++++-- fs/smb/server/smb_common.h | 2 ++ 7 files changed, 32 insertions(+), 13 deletions(-)
diff --git a/fs/smb/server/mgmt/share_config.c b/fs/smb/server/mgmt/share_config.c index e0a6b758094fc..d8d03070ae44b 100644 --- a/fs/smb/server/mgmt/share_config.c +++ b/fs/smb/server/mgmt/share_config.c @@ -15,6 +15,7 @@ #include "share_config.h" #include "user_config.h" #include "user_session.h" +#include "../connection.h" #include "../transport_ipc.h" #include "../misc.h"
@@ -120,12 +121,13 @@ static int parse_veto_list(struct ksmbd_share_config *share, return 0; }
-static struct ksmbd_share_config *share_config_request(struct unicode_map *um, +static struct ksmbd_share_config *share_config_request(struct ksmbd_work *work, const char *name) { struct ksmbd_share_config_response *resp; struct ksmbd_share_config *share = NULL; struct ksmbd_share_config *lookup; + struct unicode_map *um = work->conn->um; int ret;
resp = ksmbd_ipc_share_config_request(name); @@ -181,7 +183,14 @@ static struct ksmbd_share_config *share_config_request(struct unicode_map *um, KSMBD_SHARE_CONFIG_VETO_LIST(resp), resp->veto_list_sz); if (!ret && share->path) { + if (__ksmbd_override_fsids(work, share)) { + kill_share(share); + share = NULL; + goto out; + } + ret = kern_path(share->path, 0, &share->vfs_path); + ksmbd_revert_fsids(work); if (ret) { ksmbd_debug(SMB, "failed to access '%s'\n", share->path); @@ -214,7 +223,7 @@ static struct ksmbd_share_config *share_config_request(struct unicode_map *um, return share; }
-struct ksmbd_share_config *ksmbd_share_config_get(struct unicode_map *um, +struct ksmbd_share_config *ksmbd_share_config_get(struct ksmbd_work *work, const char *name) { struct ksmbd_share_config *share; @@ -227,7 +236,7 @@ struct ksmbd_share_config *ksmbd_share_config_get(struct unicode_map *um,
if (share) return share; - return share_config_request(um, name); + return share_config_request(work, name); }
bool ksmbd_share_veto_filename(struct ksmbd_share_config *share, diff --git a/fs/smb/server/mgmt/share_config.h b/fs/smb/server/mgmt/share_config.h index 5f591751b9236..d4ac2dd4de204 100644 --- a/fs/smb/server/mgmt/share_config.h +++ b/fs/smb/server/mgmt/share_config.h @@ -11,6 +11,8 @@ #include <linux/path.h> #include <linux/unicode.h>
+struct ksmbd_work; + struct ksmbd_share_config { char *name; char *path; @@ -68,7 +70,7 @@ static inline void ksmbd_share_config_put(struct ksmbd_share_config *share) __ksmbd_share_config_put(share); }
-struct ksmbd_share_config *ksmbd_share_config_get(struct unicode_map *um, +struct ksmbd_share_config *ksmbd_share_config_get(struct ksmbd_work *work, const char *name); bool ksmbd_share_veto_filename(struct ksmbd_share_config *share, const char *filename); diff --git a/fs/smb/server/mgmt/tree_connect.c b/fs/smb/server/mgmt/tree_connect.c index d2c81a8a11dda..94a52a75014a4 100644 --- a/fs/smb/server/mgmt/tree_connect.c +++ b/fs/smb/server/mgmt/tree_connect.c @@ -16,17 +16,18 @@ #include "user_session.h"
struct ksmbd_tree_conn_status -ksmbd_tree_conn_connect(struct ksmbd_conn *conn, struct ksmbd_session *sess, - const char *share_name) +ksmbd_tree_conn_connect(struct ksmbd_work *work, const char *share_name) { struct ksmbd_tree_conn_status status = {-ENOENT, NULL}; struct ksmbd_tree_connect_response *resp = NULL; struct ksmbd_share_config *sc; struct ksmbd_tree_connect *tree_conn = NULL; struct sockaddr *peer_addr; + struct ksmbd_conn *conn = work->conn; + struct ksmbd_session *sess = work->sess; int ret;
- sc = ksmbd_share_config_get(conn->um, share_name); + sc = ksmbd_share_config_get(work, share_name); if (!sc) return status;
@@ -61,7 +62,7 @@ ksmbd_tree_conn_connect(struct ksmbd_conn *conn, struct ksmbd_session *sess, struct ksmbd_share_config *new_sc;
ksmbd_share_config_del(sc); - new_sc = ksmbd_share_config_get(conn->um, share_name); + new_sc = ksmbd_share_config_get(work, share_name); if (!new_sc) { pr_err("Failed to update stale share config\n"); status.ret = -ESTALE; diff --git a/fs/smb/server/mgmt/tree_connect.h b/fs/smb/server/mgmt/tree_connect.h index 6377a70b811c8..a42cdd0510411 100644 --- a/fs/smb/server/mgmt/tree_connect.h +++ b/fs/smb/server/mgmt/tree_connect.h @@ -13,6 +13,7 @@ struct ksmbd_share_config; struct ksmbd_user; struct ksmbd_conn; +struct ksmbd_work;
enum { TREE_NEW = 0, @@ -50,8 +51,7 @@ static inline int test_tree_conn_flag(struct ksmbd_tree_connect *tree_conn, struct ksmbd_session;
struct ksmbd_tree_conn_status -ksmbd_tree_conn_connect(struct ksmbd_conn *conn, struct ksmbd_session *sess, - const char *share_name); +ksmbd_tree_conn_connect(struct ksmbd_work *work, const char *share_name); void ksmbd_tree_connect_put(struct ksmbd_tree_connect *tcon);
int ksmbd_tree_conn_disconnect(struct ksmbd_session *sess, diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 4ba6bf1535da1..d97c7982bb3ee 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -1971,7 +1971,7 @@ int smb2_tree_connect(struct ksmbd_work *work) ksmbd_debug(SMB, "tree connect request for tree %s treename %s\n", name, treename);
- status = ksmbd_tree_conn_connect(conn, sess, name); + status = ksmbd_tree_conn_connect(work, name); if (status.ret == KSMBD_TREE_CONN_STATUS_OK) rsp->hdr.Id.SyncId.TreeId = cpu_to_le32(status.tree_conn->id); else diff --git a/fs/smb/server/smb_common.c b/fs/smb/server/smb_common.c index e90a1e8c1951d..bdcdc0fc9cad5 100644 --- a/fs/smb/server/smb_common.c +++ b/fs/smb/server/smb_common.c @@ -729,10 +729,10 @@ bool is_asterisk(char *p) return p && p[0] == '*'; }
-int ksmbd_override_fsids(struct ksmbd_work *work) +int __ksmbd_override_fsids(struct ksmbd_work *work, + struct ksmbd_share_config *share) { struct ksmbd_session *sess = work->sess; - struct ksmbd_share_config *share = work->tcon->share_conf; struct cred *cred; struct group_info *gi; unsigned int uid; @@ -772,6 +772,11 @@ int ksmbd_override_fsids(struct ksmbd_work *work) return 0; }
+int ksmbd_override_fsids(struct ksmbd_work *work) +{ + return __ksmbd_override_fsids(work, work->tcon->share_conf); +} + void ksmbd_revert_fsids(struct ksmbd_work *work) { const struct cred *cred; diff --git a/fs/smb/server/smb_common.h b/fs/smb/server/smb_common.h index f1092519c0c28..4a3148b0167f5 100644 --- a/fs/smb/server/smb_common.h +++ b/fs/smb/server/smb_common.h @@ -447,6 +447,8 @@ int ksmbd_extract_shortname(struct ksmbd_conn *conn, int ksmbd_smb_negotiate_common(struct ksmbd_work *work, unsigned int command);
int ksmbd_smb_check_shared_mode(struct file *filp, struct ksmbd_file *curr_fp); +int __ksmbd_override_fsids(struct ksmbd_work *work, + struct ksmbd_share_config *share); int ksmbd_override_fsids(struct ksmbd_work *work); void ksmbd_revert_fsids(struct ksmbd_work *work);