fstools: fix a couple of minor code problems

Improve error handling and fix a resource leak inside an error path.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

6 files changed, 52 insertions, 19 deletions

diff --git a/libblkid-tiny/libblkid-tiny.c b/libblkid-tiny/libblkid-tiny.c
index 6e8cd81..8520f8a 100644
--- a/libblkid-tiny/libblkid-tiny.c
+++ b/libblkid-tiny/libblkid-tiny.c
@@ -87,11 +87,15 @@ unsigned char *blkid_probe_get_buffer(blkid_probe pr,
 	memset(bf, 0, sizeof(*bf));
 	bf->data = ((unsigned char *)bf) + sizeof(*bf);
 
-	lseek(pr->fd, off, SEEK_SET);
+	if (lseek(pr->fd, off, SEEK_SET) < 0) {
+		fprintf(stderr, "failed to seek\n");
+		free(bf);
+		return NULL;
+	}
 	ret = read(pr->fd, bf->data, len);
 
 	if (ret != len) {
-		fprintf(stderr, "faile to read blkid\n");
+		fprintf(stderr, "failed to read blkid\n");
 		free(bf);
 		return NULL;
 	}
@@ -212,10 +216,14 @@ int probe_block(char *block, struct blkid_struct_probe *pr)
 			int off = (mag->kboff * 1024) + mag->sboff;
 			char magic[32] = { 0 };
 
-			lseek(pr->fd, off, SEEK_SET);
-			if (read(pr->fd, magic, mag->len) < 0)
+			if (lseek(pr->fd, off, SEEK_SET) < 0) {
+				close(pr->fd);
 				return -1;
-
+			}
+			if (read(pr->fd, magic, mag->len) < 0) {
+				close(pr->fd);
+				return -1;
+			}
 			DEBUG("magic: %s %s %d\n", mag->magic, magic, mag->len);
 			if (!memcmp(mag->magic, magic, mag->len))
 				break;
diff --git a/libfstools/common.c b/libfstools/common.c
index 8dc1095..1b22d2c 100644
--- a/libfstools/common.c
+++ b/libfstools/common.c
@@ -59,13 +59,17 @@ int block_file_identify(FILE *f, uint64_t offset)
 	uint32_t magic = 0;
 	size_t n;
 
-	fseeko(f, offset, SEEK_SET);
+	if (fseeko(f, offset, SEEK_SET) < 0)
+		return -1;
+
 	n = fread(&magic, sizeof(magic), 1, f);
 	if (magic == cpu_to_le32(0x88b1f)) {
 		return FS_TARGZ;
 	}
 
-	fseeko(f, offset + 0x400, SEEK_SET);
+	if (fseeko(f, offset + 0x400, SEEK_SET) < 0)
+		return -1;
+
 	n = fread(&magic, sizeof(magic), 1, f);
 	if (n != 1)
 		return -1;
@@ -74,7 +78,9 @@ int block_file_identify(FILE *f, uint64_t offset)
 		return FS_F2FS;
 
 	magic = 0;
-	fseeko(f, offset + 0x438, SEEK_SET);
+	if (fseeko(f, offset + 0x438, SEEK_SET) < 0)
+		return -1;
+
 	n = fread(&magic, sizeof(magic), 1, f);
 	if (n != 1)
 		return -1;
diff --git a/libfstools/mount.c b/libfstools/mount.c
index 1691ce7..3d4111f 100644
--- a/libfstools/mount.c
+++ b/libfstools/mount.c
@@ -143,8 +143,11 @@ fopivot(char *rw_root, char *ro_root)
 	 * We can't really deal with these constraints without
 	 * creating two new subdirectories in /overlay.
 	 */
-	mkdir(upperdir, 0755);
-	mkdir(workdir, 0755);
+	if (mkdir(upperdir, 0755) == -1 && errno != EEXIST)
+		return -1;
+
+	if (mkdir(workdir, 0755) == -1 && errno != EEXIST)
+		return -1;
 
 	if (stat(upgrade, &st) == 0)
 		rename(upgrade, upgrade_dest);
diff --git a/libfstools/overlay.c b/libfstools/overlay.c
index d7d8f48..5de12c5 100644
--- a/libfstools/overlay.c
+++ b/libfstools/overlay.c
@@ -175,14 +175,20 @@ static int
 switch2jffs(struct volume *v)
 {
 	struct stat s;
-	int ret;
+	int ret, fd;
 
 	if (!stat(SWITCH_JFFS2, &s)) {
 		ULOG_ERR("jffs2 switch already running\n");
 		return -1;
 	}
 
-	creat(SWITCH_JFFS2, 0600);
+	fd = creat(SWITCH_JFFS2, 0600);
+	if (fd == -1) {
+		ULOG_ERR("failed - cannot create jffs2 switch mark: %m\n");
+		return -1;
+	}
+	close(fd);
+
 	ret = mount(v->blk, OVERLAYDIR, "jffs2", MS_NOATIME, NULL);
 	unlink(SWITCH_JFFS2);
 	if (ret) {
diff --git a/libfstools/partname.c b/libfstools/partname.c
index 773df8c..f59c52e 100644
--- a/libfstools/partname.c
+++ b/libfstools/partname.c
@@ -152,6 +152,9 @@ static struct volume *partname_volume_find(char *name)
 
 	devname = gl.gl_pathv[j];
 	tmp = strrchr(devname, '/');
+	if (!tmp)
+		return NULL;
+
 	*tmp = '\0';
 	devname = strrchr(devname, '/') + 1;
 
diff --git a/libfstools/snapshot.c b/libfstools/snapshot.c
index 4870cf7..5e7e847 100644
--- a/libfstools/snapshot.c
+++ b/libfstools/snapshot.c
@@ -145,7 +145,7 @@ snapshot_write_file(struct volume *v, int block, char *file, uint32_t seq, uint3
 	}
 
 	in = open(file, O_RDONLY);
-	if (in < 1) {
+	if (in < 0) {
 		ULOG_ERR("failed to open %s\n", file);
 		goto out;
 	}
@@ -161,7 +161,7 @@ snapshot_write_file(struct volume *v, int block, char *file, uint32_t seq, uint3
 	ret = 0;
 
 out:
-	if (in > 0)
+	if (in >= 0)
 		close(in);
 
 	return ret;
@@ -190,7 +190,7 @@ snapshot_read_file(struct volume *v, int block, char *file, uint32_t type)
 		return -1;
 
 	out = open(file, O_WRONLY | O_CREAT, 0700);
-	if (!out) {
+	if (out < 0) {
 		ULOG_ERR("failed to open %s\n", file);
 		return -1;
 	}
@@ -203,10 +203,14 @@ snapshot_read_file(struct volume *v, int block, char *file, uint32_t type)
 		if (hdr.length < len)
 			len = hdr.length;
 
-		if (volume_read(v, buffer, offset, len))
+		if (volume_read(v, buffer, offset, len)) {
+			close(out);
 			return -1;
-		if (write(out, buffer, len) != len)
+		}
+		if (write(out, buffer, len) != len) {
+			close(out);
 			return -1;
+		}
 		offset += len;
 		hdr.length -= len;
 	}
@@ -219,7 +223,7 @@ snapshot_read_file(struct volume *v, int block, char *file, uint32_t type)
 		return 0;
 	}
 
-        block += pad_file_size(v, hdr.length) / v->block_size;
+	block += pad_file_size(v, hdr.length) / v->block_size;
 
 	return block;
 }
@@ -334,7 +338,10 @@ mount_snapshot(struct volume *v)
 		return -1;
 	}
 	foreachdir("/overlay/", handle_whiteout);
-	mkdir("/volatile", 0700);
+	if (mkdir("/volatile", 0700) == -1 && errno != EEXIST) {
+		perror("mkdir");
+		return -1;
+	}
 	_ramoverlay("/rom", "/volatile");
 	mount_move("/rom/volatile", "/volatile", "");
 	mount_move("/rom/rom", "/rom", "");