posix_acls.c: prefer capabilities over become_root

Signed-off-by: Bjoern Jacke <bjacke@samba.org>
Reviewed-by: Christof Schmitt <cs@samba.org>
Autobuild-User(master): Björn Jacke <bjacke@samba.org>
Autobuild-Date(master): Thu Nov 16 22:39:05 UTC 2023 on atb-devel-224

diff --git a/source3/smbd/posix_acls.c b/source3/smbd/posix_acls.c
index d275bdb908b3e8f63c5fc5f41c35aabb76c2df82..530056175e005c9a68e2d8bde161d22fcf1d6119 100644 (file)
--- a/source3/smbd/posix_acls.c
+++ b/source3/smbd/posix_acls.c
@@ -2944,11 +2944,11 @@ static bool set_canon_ace_list(files_struct *fsp,
                                  "file [%s] primary group.\n",
                                  fsp_str_dbg(fsp));
 
-                       become_root();
+                       set_effective_capability(DAC_OVERRIDE_CAPABILITY);
                        sret = SMB_VFS_SYS_ACL_SET_FD(fsp,
                                                      the_acl_type,
                                                      the_acl);
-                       unbecome_root();
+                       drop_effective_capability(DAC_OVERRIDE_CAPABILITY);
                        if (sret == 0) {
                                ret = true;
                        }
@@ -3441,12 +3441,12 @@ static NTSTATUS try_chown(files_struct *fsp, uid_t uid, gid_t gid)
 
                if (has_take_ownership_priv || has_restore_priv) {
                        status = NT_STATUS_OK;
-                       become_root();
+                       set_effective_capability(DAC_OVERRIDE_CAPABILITY);
                        ret = SMB_VFS_FCHOWN(fsp, uid, gid);
                        if (ret != 0) {
                                status = map_nt_error_from_unix(errno);
                        }
-                       unbecome_root();
+                       drop_effective_capability(DAC_OVERRIDE_CAPABILITY);
                        return status;
                }
        }
@@ -3480,13 +3480,13 @@ static NTSTATUS try_chown(files_struct *fsp, uid_t uid, gid_t gid)
        }
 
        status = NT_STATUS_OK;
-       become_root();
+       set_effective_capability(DAC_OVERRIDE_CAPABILITY);
        /* Keep the current file gid the same. */
        ret = SMB_VFS_FCHOWN(fsp, uid, (gid_t)-1);
        if (ret != 0) {
                status = map_nt_error_from_unix(errno);
        }
-       unbecome_root();
+       drop_effective_capability(DAC_OVERRIDE_CAPABILITY);
 
        return status;
 }
@@ -3707,12 +3707,12 @@ NTSTATUS set_nt_acl(files_struct *fsp, uint32_t security_info_sent, const struct
 
        if (acl_perms && file_ace_list) {
                if (set_acl_as_root) {
-                       become_root();
+                       set_effective_capability(DAC_OVERRIDE_CAPABILITY);
                }
                ret = set_canon_ace_list(fsp, file_ace_list, false,
                                         &fsp->fsp_name->st, &acl_set_support);
                if (set_acl_as_root) {
-                       unbecome_root();
+                       drop_effective_capability(DAC_OVERRIDE_CAPABILITY);
                }
                if (acl_set_support && ret == false) {
                        DEBUG(3,("set_nt_acl: failed to set file acl on file "
@@ -3727,13 +3727,13 @@ NTSTATUS set_nt_acl(files_struct *fsp, uint32_t security_info_sent, const struct
        if (acl_perms && acl_set_support && fsp->fsp_flags.is_directory) {
                if (dir_ace_list) {
                        if (set_acl_as_root) {
-                               become_root();
+                               set_effective_capability(DAC_OVERRIDE_CAPABILITY);
                        }
                        ret = set_canon_ace_list(fsp, dir_ace_list, true,
                                                 &fsp->fsp_name->st,
                                                 &acl_set_support);
                        if (set_acl_as_root) {
-                               unbecome_root();
+                               drop_effective_capability(DAC_OVERRIDE_CAPABILITY);
                        }
                        if (ret == false) {
                                DEBUG(3,("set_nt_acl: failed to set default "
@@ -3751,11 +3751,11 @@ NTSTATUS set_nt_acl(files_struct *fsp, uint32_t security_info_sent, const struct
                         */
 
                        if (set_acl_as_root) {
-                               become_root();
+                               set_effective_capability(DAC_OVERRIDE_CAPABILITY);
                        }
                        sret = SMB_VFS_SYS_ACL_DELETE_DEF_FD(fsp);
                        if (set_acl_as_root) {
-                               unbecome_root();
+                               drop_effective_capability(DAC_OVERRIDE_CAPABILITY);
                        }
                        if (sret == -1) {
                                if (acl_group_override_fsp(fsp)) {
@@ -3765,10 +3765,10 @@ NTSTATUS set_nt_acl(files_struct *fsp, uint32_t security_info_sent, const struct
                                                 "Override delete_def_acl\n",
                                                 fsp_str_dbg(fsp)));
 
-                                       become_root();
+                                       set_effective_capability(DAC_OVERRIDE_CAPABILITY);
                                        sret =
                                            SMB_VFS_SYS_ACL_DELETE_DEF_FD(fsp);
-                                       unbecome_root();
+                                       drop_effective_capability(DAC_OVERRIDE_CAPABILITY);
                                }
 
                                if (sret == -1) {
@@ -3786,14 +3786,14 @@ NTSTATUS set_nt_acl(files_struct *fsp, uint32_t security_info_sent, const struct
 
        if (acl_set_support) {
                if (set_acl_as_root) {
-                       become_root();
+                       set_effective_capability(DAC_OVERRIDE_CAPABILITY);
                }
                store_inheritance_attributes(fsp,
                                file_ace_list,
                                dir_ace_list,
                                psd->type);
                if (set_acl_as_root) {
-                       unbecome_root();
+                       drop_effective_capability(DAC_OVERRIDE_CAPABILITY);
                }
        }
 
@@ -3820,11 +3820,11 @@ NTSTATUS set_nt_acl(files_struct *fsp, uint32_t security_info_sent, const struct
                                 fsp_str_dbg(fsp), (unsigned int)posix_perms));
 
                        if (set_acl_as_root) {
-                               become_root();
+                               set_effective_capability(DAC_OVERRIDE_CAPABILITY);
                        }
                        sret = SMB_VFS_FCHMOD(fsp, posix_perms);
                        if (set_acl_as_root) {
-                               unbecome_root();
+                               drop_effective_capability(DAC_OVERRIDE_CAPABILITY);
                        }
                        if(sret == -1) {
                                if (acl_group_override_fsp(fsp)) {
@@ -3834,9 +3834,9 @@ NTSTATUS set_nt_acl(files_struct *fsp, uint32_t security_info_sent, const struct
                                                 "Override chmod\n",
                                                 fsp_str_dbg(fsp)));
 
-                                       become_root();
+                                       set_effective_capability(DAC_OVERRIDE_CAPABILITY);
                                        sret = SMB_VFS_FCHMOD(fsp, posix_perms);
-                                       unbecome_root();
+                                       drop_effective_capability(DAC_OVERRIDE_CAPABILITY);
                                }
 
                                if (sret == -1) {