From: Jaroslav Kysela <perex@perex.cz>
Date: Mon, 19 Oct 2026 07:13:19 +0000 (+0200)
Subject: Revert "ucm: confine sysw and cfg-save paths with realpath()"
X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=defbff6613267ebcd3c2a1d04d7254204c5c47c2;p=alsa-lib.git

Revert "ucm: confine sysw and cfg-save paths with realpath()"

This reverts commit a47c8bc3fef190e7eb463283230263c82208597a.

The sysw change is too expensive and cfg-save saves data to /var/lib/alsa tree.

Link: https://github.com/alsa-project/alsa-lib/pull/527
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---

diff --git a/src/ucm/main.c b/src/ucm/main.c
index b27e71f0..d2b3c2d9 100644
--- a/src/ucm/main.c
+++ b/src/ucm/main.c
@@ -523,20 +523,6 @@ static int execute_cset(snd_ctl_t *ctl, const char *cset, unsigned int type)
 	return err;
 }
 
-static bool check_realpath(const char *path, const char *target)
-{
-	char *resolved = realpath(path, NULL);
-
-	if (!resolved)
-		return false;
-	if (strncmp(resolved, target, strlen(target)) != 0) {
-		free(resolved);
-		return false;
-	}
-	free(resolved);
-	return true;
-}
-
 static int execute_sysw(const char *sysw)
 {
 	char path[PATH_MAX];
@@ -584,12 +570,6 @@ static int execute_sysw(const char *sysw)
 	}
 	snprintf(path, sizeof(path), "%s/%s", e, s);
 
-	if (!check_realpath(path, e)) {
-		free(s);
-		snd_error(UCM, "sysw path escapes sysfs root: '%s'", path);
-		return -EINVAL;
-	}
-
 	fd = open(path, O_WRONLY|O_CLOEXEC);
 	if (fd < 0) {
 		free(s);
@@ -623,7 +603,6 @@ static int execute_cfgsave(snd_use_case_mgr_t *uc_mgr, const char *filename)
 	snd_config_t *config = uc_mgr->local_config;
 	char *file, *root;
 	snd_output_t *out;
-	const char *runtime;
 	bool with_root = false;
 	int err = 0;
 
@@ -646,13 +625,6 @@ static int execute_cfgsave(snd_use_case_mgr_t *uc_mgr, const char *filename)
 		}
 	}
 
-	runtime = getenv("XDG_RUNTIME_DIR");
-	if (!runtime)
-		runtime = "/tmp";
-	if (!check_realpath(file, runtime)) {
-		snd_error(UCM, "cfg-save path escapes runtime dir: '%s'", file);
-		return -EINVAL;
-	}
 	err = snd_output_stdio_open(&out, file, "w+");
 	if (err < 0) {
 		snd_error(UCM, "unable to open file '%s': %s", file, snd_strerror(err));