[PATCH 0/5] multipath-tools: minor fixes in preparation of 0.14.0

[PATCH 0/5] multipath-tools: minor fixes in preparation of 0.14.0

[Martin Wilck]

This series fixes the double-free in kpartx introduced in 8c39e60 ("kpartx:
fix some memory leaks"), removes the long-obsolete "hotplug" mode of
kpartx, fixing another potential memory leak in the process, fixes a
false positive compiler warning, and adds two developer convenience
options to the Makefiles.

Martin Wilck (5):
  kpartx: avoid double-free of mapname
  kpartx: remove "hotplug" mode
  multipathd: fix an uninitialized variable warning
  Makefiles: add "ASAN=1" make parameter for AddressSanitizer
  Makefiles: add "OPT=" make parameter

 .github/actions/spelling/expect.txt |  3 +
 Makefile.inc                        | 12 +++-
 README.md                           |  9 +++
 kpartx/kpartx.c                     | 94 ++++-------------------------
 multipathd/main.c                   |  2 +-
 5 files changed, 35 insertions(+), 85 deletions(-)

-- 
2.52.0

[PATCH 1/5] kpartx: avoid double-free of mapname

[Martin Wilck]

The variable mapname is sometimes allocated and sometimes not.
To avoid double-free and still free allocated memory cleanly,
introduce a helper pointer for storing possibly allocated memory.

Signed-off-by: Martin Wilck <mwilck@suse.com>
---
 kpartx/kpartx.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/kpartx/kpartx.c b/kpartx/kpartx.c
index 7ec89b4..6f2ec4e 100644
--- a/kpartx/kpartx.c
+++ b/kpartx/kpartx.c
@@ -245,7 +245,8 @@ main(int argc, char **argv){
 	char *loopdev __attribute__((cleanup(cleanup_charp))) = NULL;
 	char *delim __attribute__((cleanup(cleanup_charp))) = NULL;
 	char *uuid __attribute__((cleanup(cleanup_charp))) = NULL;
-	char *mapname __attribute__((cleanup(cleanup_charp))) = NULL;
+	char *_mapname __attribute__((cleanup(cleanup_charp))) = NULL;
+	char *mapname;
 	int hotplug = 0;
 	int loopcreated = 0;
 	struct stat buf;
@@ -388,11 +389,15 @@ main(int argc, char **argv){
 	off = find_devname_offset(device);
 
 	if (!loopdev) {
-		mapname = dm_mapname(major(buf.st_rdev), minor(buf.st_rdev));
-		if (mapname)
-			uuid = dm_mapuuid(mapname);
+		_mapname = dm_mapname(major(buf.st_rdev), minor(buf.st_rdev));
+		if (_mapname)
+			uuid = dm_mapuuid(_mapname);
 	}
 
+	mapname = _mapname;
+	if (!mapname)
+		mapname = device + off;
+
 	/*
 	 * We are called for a non-DM device.
 	 * Make up a fake UUID for the device, unless "-d -f" is given.
@@ -402,9 +407,6 @@ main(int argc, char **argv){
 	if (!uuid && !(what == DELETE && force_devmap))
 		uuid = nondm_create_uuid(buf.st_rdev);
 
-	if (!mapname)
-		mapname = device + off;
-
 	if (delim == NULL) {
 		delim = xmalloc(DELIM_SIZE);
 		memset(delim, 0, DELIM_SIZE);
-- 
2.52.0

[PATCH 2/5] kpartx: remove "hotplug" mode

[Martin Wilck]

This functionality has been obsolete for a long time.

Signed-off-by: Martin Wilck <mwilck@suse.com>
---
 kpartx/kpartx.c | 78 +++----------------------------------------------
 1 file changed, 4 insertions(+), 74 deletions(-)

diff --git a/kpartx/kpartx.c b/kpartx/kpartx.c
index 6f2ec4e..9bdd204 100644
--- a/kpartx/kpartx.c
+++ b/kpartx/kpartx.c
@@ -145,56 +145,6 @@ find_devname_offset (char * device)
 	return (int)(q - device);
 }
 
-static char *
-get_hotplug_device(void)
-{
-	unsigned int major, minor, off, len;
-	char *mapname;
-	char *devname = NULL;
-	char *device = NULL;
-	char *var = NULL;
-	struct stat buf;
-
-	var = getenv("ACTION");
-
-	if (!var || strcmp(var, "add"))
-		return NULL;
-
-	/* Get dm mapname for hotpluged device. */
-	if (!(devname = getenv("DEVNAME")))
-		return NULL;
-
-	if (stat(devname, &buf))
-		return NULL;
-
-	major = major(buf.st_rdev);
-	minor = minor(buf.st_rdev);
-
-	if (!(mapname = dm_mapname(major, minor))) /* Not dm device. */
-		return NULL;
-
-	off = find_devname_offset(devname);
-	len = strlen(mapname);
-
-	/* Dirname + mapname + \0 */
-	if (!(device = (char *)malloc(sizeof(char) * (off + len + 1)))) {
-		free(mapname);
-		return NULL;
-	}
-
-	/* Create new device name. */
-	snprintf(device, off + 1, "%s", devname);
-	snprintf(device + off, len + 1, "%s", mapname);
-
-	if (strlen(device) != (off + len)) {
-		free(device);
-		free(mapname);
-		return NULL;
-	}
-	free(mapname);
-	return device;
-}
-
 static int
 check_uuid(char *uuid, char *part_uuid, char **err_msg) {
 	char *map_uuid = strchr(part_uuid, '-');
@@ -239,7 +189,7 @@ main(int argc, char **argv){
 	struct slice all;
 	struct pt *ptp;
 	enum action what = LIST;
-	char *type, *diskdevice, *device, *progname;
+	char *type, *diskdevice, *device;
 	int verbose = 0;
 	char partname[PARTNAME_SIZE], params[PARTNAME_SIZE + 16];
 	char *loopdev __attribute__((cleanup(cleanup_charp))) = NULL;
@@ -247,7 +197,6 @@ main(int argc, char **argv){
 	char *uuid __attribute__((cleanup(cleanup_charp))) = NULL;
 	char *_mapname __attribute__((cleanup(cleanup_charp))) = NULL;
 	char *mapname;
-	int hotplug = 0;
 	int loopcreated = 0;
 	struct stat buf;
 
@@ -258,24 +207,7 @@ main(int argc, char **argv){
 	memset(&all, 0, sizeof(all));
 	memset(&partname, 0, sizeof(partname));
 
-	/* Check whether hotplug mode. */
-	progname = strrchr(argv[0], '/');
-
-	if (!progname)
-		progname = argv[0];
-	else
-		progname++;
-
-	if (!strcmp(progname, "kpartx.dev")) { /* Hotplug mode */
-		hotplug = 1;
-
-		/* Setup for original kpartx variables */
-		if (!(device = get_hotplug_device()))
-			exit(1);
-
-		diskdevice = device;
-		what = ADD;
-	} else if (argc < 2) {
+	if (argc < 2) {
 		usage();
 		exit(1);
 	}
@@ -337,12 +269,10 @@ main(int argc, char **argv){
 		exit(1);
 	}
 
-	if (hotplug) {
-		/* already got [disk]device */
-	} else if (optind == argc-2) {
+	if (optind == argc - 2) {
 		device = argv[optind];
 		diskdevice = argv[optind+1];
-	} else if (optind == argc-1) {
+	} else if (optind == argc - 1) {
 		diskdevice = device = argv[optind];
 	} else {
 		usage();
-- 
2.52.0

[PATCH 3/5] multipathd: fix an uninitialized variable warning

[Martin Wilck]

This isn't necessary in practice, but it fixes a compile warning.

Signed-off-by: Martin Wilck <mwilck@suse.com>
---
 multipathd/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/multipathd/main.c b/multipathd/main.c
index 356091e..61e0ea3 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -3905,7 +3905,7 @@ child (__attribute__((unused)) void *param)
 	int rc;
 	struct config *conf;
 	char *envp;
-	enum daemon_status state;
+	enum daemon_status state = DAEMON_INIT;
 	int exit_code = 1;
 	int fpin_marginal_paths = 0;
 
-- 
2.52.0

[PATCH 4/5] Makefiles: add "ASAN=1" make parameter for AddressSanitizer

[Martin Wilck]

It's now possible to enable AddressSanitizer by passing the parameter
`ASAN=1` on the "make" command line.

Signed-off-by: Martin Wilck <mwilck@suse.com>
---
 .github/actions/spelling/expect.txt | 3 +++
 Makefile.inc                        | 7 +++++--
 README.md                           | 3 +++
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/.github/actions/spelling/expect.txt b/.github/actions/spelling/expect.txt
index 0b680aa..29ca8e8 100644
--- a/.github/actions/spelling/expect.txt
+++ b/.github/actions/spelling/expect.txt
@@ -6,6 +6,7 @@ alloc
 alltgpt
 alua
 aptpl
+ASAN
 ascq
 ata
 autoconfig
@@ -78,6 +79,7 @@ getrlimit
 getuid
 github
 gitlab
+google
 GPT
 hbtl
 hds
@@ -197,6 +199,7 @@ rpmbuild
 rport
 rtpi
 rtprio
+sanitizer
 sas
 sbp
 scsi
diff --git a/Makefile.inc b/Makefile.inc
index 539415d..8356254 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -9,6 +9,9 @@
 # Uncomment to disable dmevents polling support
 # ENABLE_DMEVENTS_POLL = 0
 #
+# Use ASAN=1 on make command line to enable address sanitizer
+ASAN := 
+#
 # Readline library to use, libedit, libreadline, or empty
 # Caution: Using libreadline may make the multipathd binary undistributable,
 # see https://github.com/opensvc/multipath-tools/issues/36
@@ -122,11 +125,11 @@ CPPFLAGS	:= $(FORTIFY_OPT) $(CPPFLAGS) $(D_URCU_VERSION) $(D_CMOCKA_VERSION) \
 		   -DWSTRINGOP_TRUNCATION=$(if $(WSTRINGOP_TRUNCATION),1,0) \
 		   -MMD -MP
 CFLAGS		:= -std=$(C_STD) $(CFLAGS) $(OPTFLAGS) $(WARNFLAGS) -pipe \
-		   -fexceptions -fno-strict-aliasing
+		   -fexceptions -fno-strict-aliasing $(if $(ASAN),-fsanitize=address)
 BIN_CFLAGS	:= -fPIE -DPIE
 LIB_CFLAGS	:= -fPIC
 SHARED_FLAGS	:= -shared
-LDFLAGS		:= $(LDFLAGS) -Wl,-z,relro -Wl,-z,now -Wl,-z,defs
+LDFLAGS		:= $(LDFLAGS) -Wl,-z,relro -Wl,-z,now -Wl,-z,defs $(if $(ASAN),-lasan)
 BIN_LDFLAGS	:= -pie
 
 # Source code directories. Don't modify.
diff --git a/README.md b/README.md
index 530caed..8ff139c 100644
--- a/README.md
+++ b/README.md
@@ -107,6 +107,9 @@ See "Passing standard compiler flags" below for an exception.
 The following variables can be passed to the `make` command line:
 
  * `V=1`: enable verbose build.
+ * `ASAN=1`: Enable
+   [AddressSanitizer](https://github.com/google/sanitizers/wiki/AddressSanitizerLeakSanitizer)
+   during build for debugging memory allocation. This is off by default.
  * `plugindir="/some/path"`: directory where libmultipath plugins (path
    checkers, prioritizers, and foreign multipath support) will be looked up.
    This used to be the run-time option `multipath_dir` in earlier versions.
-- 
2.52.0

[PATCH 5/5] Makefiles: add "OPT=" make parameter

[Martin Wilck]

Our OPTFLAGS variable contains stack protection options which are
intended to be overridable by distribution build scripts. When developers
just want to experiment with optimization levels, they often just want
to modify the `-O` level. Introduce a variable `OPT` that allows to do just
that by passing e.g. `OPT=-O0` to the `make` command line.

Signed-off-by: Martin Wilck <mwilck@suse.com>
---
 Makefile.inc | 5 ++++-
 README.md    | 6 ++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/Makefile.inc b/Makefile.inc
index 8356254..c6aa6ed 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -12,6 +12,9 @@
 # Use ASAN=1 on make command line to enable address sanitizer
 ASAN := 
 #
+# Override on make command line if desired
+OPT := -O2
+
 # Readline library to use, libedit, libreadline, or empty
 # Caution: Using libreadline may make the multipathd binary undistributable,
 # see https://github.com/opensvc/multipath-tools/issues/36
@@ -105,7 +108,7 @@ SYSTEMD_LIBDEPS := $(if $(SYSTEMD),$(if $(shell test $(SYSTEMD) -gt 209 && echo
 MODPROBE_UNIT := $(shell test "0$(SYSTEMD)" -lt 245 2>/dev/null || \
 			echo "modprobe@dm_multipath.service")
 
-OPTFLAGS	:= -O2 -g $(STACKPROT) --param=ssp-buffer-size=4
+OPTFLAGS	:= $(OPT) -g $(STACKPROT) --param=ssp-buffer-size=4
 
 # Set WARN_ONLY=1 to avoid compilation erroring out due to warnings. Useful during development.
 WARN_ONLY       :=
diff --git a/README.md b/README.md
index 8ff139c..888998b 100644
--- a/README.md
+++ b/README.md
@@ -107,6 +107,12 @@ See "Passing standard compiler flags" below for an exception.
 The following variables can be passed to the `make` command line:
 
  * `V=1`: enable verbose build.
+ * `OPT=`: set optimization flags. You may want to set `OPT="-O0"` for
+   debugging, for example. The default is `-O2`. Note that it is also
+   possible to set `OPTFLAGS`, which takes precedence over `OPT`. `OPTFLAGS`
+   sets additional options by default, which are intended for distribution
+   build environments to override. For quick customization of the optimization
+   level, use `OPT`.
  * `ASAN=1`: Enable
    [AddressSanitizer](https://github.com/google/sanitizers/wiki/AddressSanitizerLeakSanitizer)
    during build for debugging memory allocation. This is off by default.
-- 
2.52.0

Re: [PATCH 0/5] multipath-tools: minor fixes in preparation of 0.14.0

[Benjamin Marzinski]

On Fri, Jan 16, 2026 at 12:30:37PM +0100, Martin Wilck wrote:
> This series fixes the double-free in kpartx introduced in 8c39e60 ("kpartx:
> fix some memory leaks"), removes the long-obsolete "hotplug" mode of
> kpartx, fixing another potential memory leak in the process, fixes a
> false positive compiler warning, and adds two developer convenience
> options to the Makefiles.

For the set:
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>

> 
> Martin Wilck (5):
>   kpartx: avoid double-free of mapname
>   kpartx: remove "hotplug" mode
>   multipathd: fix an uninitialized variable warning
>   Makefiles: add "ASAN=1" make parameter for AddressSanitizer
>   Makefiles: add "OPT=" make parameter
> 
>  .github/actions/spelling/expect.txt |  3 +
>  Makefile.inc                        | 12 +++-
>  README.md                           |  9 +++
>  kpartx/kpartx.c                     | 94 ++++-------------------------
>  multipathd/main.c                   |  2 +-
>  5 files changed, 35 insertions(+), 85 deletions(-)
> 
> -- 
> 2.52.0