diff --git a/src/shared/creds-util.c b/src/shared/creds-util.c index ecf90e2084..f5ac15be44 100644 --- a/src/shared/creds-util.c +++ b/src/shared/creds-util.c @@ -9,6 +9,7 @@ #include "sd-id128.h" #include "blockdev-util.h" +#include "capability-util.h" #include "chattr-util.h" #include "creds-util.h" #include "def.h" @@ -173,10 +174,15 @@ static int make_credential_host_secret( assert(dfd >= 0); assert(fn); - fd = openat(dfd, ".", O_CLOEXEC|O_WRONLY|O_TMPFILE, 0400); + /* For non-root users creating a temporary file using the openat(2) over "." will fail later, in the + * linkat(2) step at the end. The reason is that linkat(2) requires the CAP_DAC_READ_SEARCH + * capability when it uses the AT_EMPTY_PATH flag. */ + if (have_effective_cap(CAP_DAC_READ_SEARCH) > 0) { + fd = openat(dfd, ".", O_CLOEXEC|O_WRONLY|O_TMPFILE, 0400); + if (fd < 0) + log_debug_errno(errno, "Failed to create temporary credential file with O_TMPFILE, proceeding without: %m"); + } if (fd < 0) { - log_debug_errno(errno, "Failed to create temporary credential file with O_TMPFILE, proceeding without: %m"); - if (asprintf(&t, "credential.secret.%016" PRIx64, random_u64()) < 0) return -ENOMEM;