File pull-5.patch of Package thunderbolt-utils

From e7c51d2dde402d4bc9ce23ec51e845c9a833439e Mon Sep 17 00:00:00 2001
From: Jan Engelhardt <jengelh@inai.de>
Date: Wed, 19 Jul 2023 10:01:57 +0200
Subject: [PATCH] lstbt: fix crash when {sysfs}/vendor etc. is absent

With Linux 6.3.9, I observed:

```
cat: /sys/bus/thunderbolt/devices/0-0/vendor: No such file or directory
cat: /sys/bus/thunderbolt/devices/0-0/device: No such file or directory
Segmentation fault (core dumped)
```
---
 lib/helpers.c | 13 ++++++++-----
 lib/helpers.h |  5 +++++
 lib/lstbt.c   |  9 +++++----
 lib/lstbt_r.c | 18 +++++++++++-------
 lib/lstbt_v.c |  9 +++++----
 5 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/lib/helpers.c b/lib/helpers.c
index f1f7247..bf4fc75 100644
--- a/lib/helpers.c
+++ b/lib/helpers.c
@@ -652,11 +652,14 @@ void dump_vdid(const char *router)
 
 	snprintf(did_path, sizeof(did_path), "cat %s%s/device", tbt_sysfs_path, router);
 	did = do_bash_cmd(did_path);
-
-	printf("ID %04x:%04x ", strtouh(vid), strtouh(did));
-
-	free(vid);
-	free(did);
+	if (vid != NULL && did != NULL)
+		printf("ID %04x:%04x ", strtouh(vid), strtouh(did));
+	else
+		printf("ID -- ");
+	if (vid != NULL)
+		free(vid);
+	if (did != NULL)
+		free(did);
 }
 
 /* Dump the generation of the router */
diff --git a/lib/helpers.h b/lib/helpers.h
index a3af187..b0081f1 100644
--- a/lib/helpers.h
+++ b/lib/helpers.h
@@ -76,3 +76,8 @@ int __main(char *domain, char *depth, char *device, bool retimer, bool tree,
 	   u8 verbose);
 char** ameliorate_args(int argc, char **argv);
 bool is_input_printable(int argc, char **argv);
+
+static inline const char *znul(const char *s)
+{
+	return s != NULL ? s : "";
+}
diff --git a/lib/lstbt.c b/lib/lstbt.c
index 8575efe..a070d47 100644
--- a/lib/lstbt.c
+++ b/lib/lstbt.c
@@ -40,10 +40,11 @@ static void dump_name(const char *router)
 	snprintf(d_path, sizeof(d_path), "cat %s%s/device_name", tbt_sysfs_path, router);
 	device = do_bash_cmd(d_path);
 
-	printf("%s %s ", vendor, device);
-
-	free(vendor);
-	free(device);
+	printf("%s %s ", znul(vendor), znul(device));
+	if (vendor != NULL)
+		free(vendor);
+	if (device != NULL)
+		free(device);
 }
 
 static bool dump_router(const char *router)
diff --git a/lib/lstbt_r.c b/lib/lstbt_r.c
index 5304bb1..242b554 100644
--- a/lib/lstbt_r.c
+++ b/lib/lstbt_r.c
@@ -78,9 +78,9 @@ static void dump_retimer_nvm_version(const char *retimer)
 		 retimer);
 
 	ver = do_bash_cmd(path);
-	printf("NVM %s\n", ver);
-
-	free(ver);
+	printf("NVM %s\n", znul(ver));
+	if (ver != NULL)
+		free(ver);
 }
 
 /* Dumps the retimer */
@@ -124,12 +124,16 @@ static bool dump_retimer(const char *retimer)
 	snprintf(did_path, sizeof(did_path), "cat %s%s/device", tbt_sysfs_path, retimer);
 	did = do_bash_cmd(did_path);
 
-	printf("ID %04x:%04x ", strtouh(vid), strtouh(did));
+	if (vid != NULL && did != NULL)
+		printf("ID %04x:%04x ", strtouh(vid), strtouh(did));
+	else
+		printf("-- ");
 
 	dump_retimer_nvm_version(retimer);
-
-	free(vid);
-	free(did);
+	if (vid != NULL)
+		free(vid);
+	if (did != NULL)
+		free(did);
 	free(router);
 
 	return true;
diff --git a/lib/lstbt_v.c b/lib/lstbt_v.c
index 0b73169..8edc43a 100644
--- a/lib/lstbt_v.c
+++ b/lib/lstbt_v.c
@@ -37,10 +37,11 @@ static void dump_name(const char *router)
 	snprintf(d_path, sizeof(d_path), "cat %s%s/device_name", tbt_sysfs_path, router);
 	device = do_bash_cmd(d_path);
 
-	printf("%s %s ", vendor, device);
-
-	free(vendor);
-	free(device);
+	printf("%s: %s %s ", router, znul(vendor), znul(device));
+	if (vendor != NULL)
+		free(vendor);
+	if (device != NULL)
+		free(device);
 }
 
 static void dump_spaces(u64 spaces)
-- 
2.41.0