[PATCH 1/2] mdmon: fix segfault

[PATCH 1/2] mdmon: fix segfault

[Mateusz Kusiak]

Mdmon crashes if stat2devnm returns null.
Use open_mddev to check if device is mddevice and get name using
fd2devnm.
Refactor container name handling.

Signed-off-by: Mateusz Kusiak <mateusz.kusiak@intel.com>
---
 Makefile |  2 +-
 mdmon.c  | 26 ++++++++++++--------------
 2 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/Makefile b/Makefile
index ec1f99ed..5eac1a4e 100644
--- a/Makefile
+++ b/Makefile
@@ -160,7 +160,7 @@ SRCS =  $(patsubst %.o,%.c,$(OBJS))
 
 INCL = mdadm.h part.h bitmap.h
 
-MON_OBJS = mdmon.o monitor.o managemon.o uuid.o util.o maps.o mdstat.o sysfs.o \
+MON_OBJS = mdmon.o monitor.o managemon.o uuid.o util.o maps.o mdstat.o sysfs.o config.o mapfile.o mdopen.o\
 	policy.o lib.o \
 	Kill.o sg_io.o dlink.o ReadMe.o super-intel.o \
 	super-mbr.o super-gpt.o \
diff --git a/mdmon.c b/mdmon.c
index e9d035eb..ecf52dc8 100644
--- a/mdmon.c
+++ b/mdmon.c
@@ -363,14 +363,14 @@ int main(int argc, char *argv[])
 	}
 
 	if (all == 0 && container_name == NULL) {
-		if (argv[optind])
-			container_name = argv[optind];
+		if (argv[optind]) {
+			container_name = get_md_name(argv[optind]);
+			if (!container_name)
+				container_name = argv[optind];
+		}
 	}
 
-	if (container_name == NULL)
-		usage();
-
-	if (argc - optind > 1)
+	if (container_name == NULL || argc - optind > 1)
 		usage();
 
 	if (strcmp(container_name, "/proc/mdstat") == 0)
@@ -402,21 +402,19 @@ int main(int argc, char *argv[])
 		free_mdstat(mdstat);
 
 		return status;
-	} else if (strncmp(container_name, "md", 2) == 0) {
-		int id = devnm2devid(container_name);
-		if (id)
-			devnm = container_name;
 	} else {
-		struct stat st;
+		int mdfd = open_mddev(container_name, 1);
 
-		if (stat(container_name, &st) == 0)
-			devnm = xstrdup(stat2devnm(&st));
+		if (mdfd < 0)
+			return 1;
+		devnm = fd2devnm(mdfd);
+		close(mdfd);
 	}
 
 	if (!devnm) {
 		pr_err("%s is not a valid md device name\n",
 			container_name);
-		exit(1);
+		return 1;
 	}
 	return mdmon(devnm, dofork && do_fork(), takeover);
 }
-- 
2.26.2

[PATCH 2/2] util: remove obsolete code from get_md_name

[Mateusz Kusiak]

get_md_name() is used only with mdstat entries.
Remove dead code and simplyfy function.

Remove redundadnt checks from mdmon.c

Signed-off-by: Mateusz Kusiak <mateusz.kusiak@intel.com>
---
 mdmon.c |  8 +++-----
 util.c  | 51 +++++++++++++++++----------------------------------
 2 files changed, 20 insertions(+), 39 deletions(-)

diff --git a/mdmon.c b/mdmon.c
index ecf52dc8..60ba3182 100644
--- a/mdmon.c
+++ b/mdmon.c
@@ -366,7 +366,7 @@ int main(int argc, char *argv[])
 		if (argv[optind]) {
 			container_name = get_md_name(argv[optind]);
 			if (!container_name)
-				container_name = argv[optind];
+				return 1;
 		}
 	}
 
@@ -403,11 +403,9 @@ int main(int argc, char *argv[])
 
 		return status;
 	} else {
-		int mdfd = open_mddev(container_name, 1);
-
-		if (mdfd < 0)
-			return 1;
+		int mdfd = open_mddev(container_name, 0);
 		devnm = fd2devnm(mdfd);
+
 		close(mdfd);
 	}
 
diff --git a/util.c b/util.c
index 26ffdcea..9cd89fa4 100644
--- a/util.c
+++ b/util.c
@@ -968,47 +968,30 @@ dev_t devnm2devid(char *devnm)
 	return 0;
 }
 
+/**
+ * get_md_name() - Get main dev node of the md device.
+ * @devnm: Md device name or path.
+ *
+ * Function checks if the full name was passed and returns md name
+ * if it is the MD device.
+ *
+ * Return: Main dev node of the md device or NULL if not found.
+ */
 char *get_md_name(char *devnm)
 {
-	/* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
-	/* if dev < 0, want /dev/md/d%d or find mdp in /proc/devices ... */
-
-	static char devname[50];
+	static char devname[NAME_MAX];
 	struct stat stb;
-	dev_t rdev = devnm2devid(devnm);
-	char *dn;
 
-	if (rdev == 0)
-		return 0;
-	if (strncmp(devnm, "md_", 3) == 0) {
-		snprintf(devname, sizeof(devname), "/dev/md/%s",
-			devnm + 3);
-		if (stat(devname, &stb) == 0 &&
-		    (S_IFMT&stb.st_mode) == S_IFBLK && (stb.st_rdev == rdev))
-			return devname;
-	}
-	snprintf(devname, sizeof(devname), "/dev/%s", devnm);
-	if (stat(devname, &stb) == 0 && (S_IFMT&stb.st_mode) == S_IFBLK &&
-	    (stb.st_rdev == rdev))
-		return devname;
+	if (strncmp(devnm, "/dev/", 5) == 0)
+		snprintf(devname, sizeof(devname), "%s", devnm);
+	else
+		snprintf(devname, sizeof(devname), "/dev/%s", devnm);
 
-	snprintf(devname, sizeof(devname), "/dev/md/%s", devnm+2);
-	if (stat(devname, &stb) == 0 && (S_IFMT&stb.st_mode) == S_IFBLK &&
-	    (stb.st_rdev == rdev))
+	if (!is_mddev(devname))
+		return NULL;
+	if (stat(devname, &stb) == 0 && (S_IFMT&stb.st_mode) == S_IFBLK)
 		return devname;
 
-	dn = map_dev(major(rdev), minor(rdev), 0);
-	if (dn)
-		return dn;
-	snprintf(devname, sizeof(devname), "/dev/.tmp.%s", devnm);
-	if (mknod(devname, S_IFBLK | 0600, rdev) == -1)
-		if (errno != EEXIST)
-			return NULL;
-
-	if (stat(devname, &stb) == 0 && (S_IFMT&stb.st_mode) == S_IFBLK &&
-	    (stb.st_rdev == rdev))
-		return devname;
-	unlink(devname);
 	return NULL;
 }
 
-- 
2.26.2

Re: [PATCH 2/2] util: remove obsolete code from get_md_name

[Jes Sorensen]

On 1/2/23 03:46, Mateusz Kusiak wrote:
> get_md_name() is used only with mdstat entries.
> Remove dead code and simplyfy function.
> 
> Remove redundadnt checks from mdmon.c
> 
> Signed-off-by: Mateusz Kusiak <mateusz.kusiak@intel.com>
> ---
>  mdmon.c |  8 +++-----
>  util.c  | 51 +++++++++++++++++----------------------------------
>  2 files changed, 20 insertions(+), 39 deletions(-)

Applied!

Thanks,
Jes

Re: [PATCH 1/2] mdmon: fix segfault

[Jes Sorensen]

On 1/2/23 03:46, Mateusz Kusiak wrote:
> Mdmon crashes if stat2devnm returns null.
> Use open_mddev to check if device is mddevice and get name using
> fd2devnm.
> Refactor container name handling.
> 
> Signed-off-by: Mateusz Kusiak <mateusz.kusiak@intel.com>
> ---
>  Makefile |  2 +-
>  mdmon.c  | 26 ++++++++++++--------------
>  2 files changed, 13 insertions(+), 15 deletions(-)
> 

Applied!

Thanks,
Jes