chiark / gitweb /
vol_id: fix sloppy error handling
authorKay Sievers <kay.sievers@suse.de>
Wed, 17 Aug 2005 14:58:19 +0000 (16:58 +0200)
committerKay Sievers <kay.sievers@suse.de>
Wed, 17 Aug 2005 14:58:19 +0000 (16:58 +0200)
vol_id segfaults if read() fails on broken devices reporting
the wrong size.

Thanks to Erhard Schultchen for the debugging.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
extras/volume_id/volume_id/util.c
extras/volume_id/volume_id/volume_id.h

index 868d673..62b96a3 100644 (file)
@@ -204,19 +204,30 @@ uint8_t *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len)
        if (off + len <= SB_BUFFER_SIZE) {
                if (id->sbbuf == NULL) {
                        id->sbbuf = malloc(SB_BUFFER_SIZE);
-                       if (id->sbbuf == NULL)
+                       if (id->sbbuf == NULL) {
+                               dbg("error malloc");
                                return NULL;
+                       }
                }
 
                /* check if we need to read */
                if ((off + len) > id->sbbuf_len) {
                        dbg("read sbbuf len:0x%llx", (unsigned long long) (off + len));
-                       lseek(id->fd, 0, SEEK_SET);
+                       if (lseek(id->fd, 0, SEEK_SET) < 0) {
+                               dbg("lseek failed (%s)", strerror(errno));
+                               return NULL;
+                       }
                        buf_len = read(id->fd, id->sbbuf, off + len);
+                       if (buf_len < 0) {
+                               dbg("read failed (%s)", strerror(errno));
+                               return NULL;
+                       }
                        dbg("got 0x%zx (%zi) bytes", buf_len, buf_len);
                        id->sbbuf_len = buf_len;
-                       if (buf_len < off + len)
+                       if (buf_len < off + len) {
+                               dbg("requested 0x%zx bytes, got only 0x%zx bytes", len, buf_len);
                                return NULL;
+                       }
                }
 
                return &(id->sbbuf[off]);
@@ -229,16 +240,24 @@ uint8_t *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len)
                /* get seek buffer */
                if (id->seekbuf == NULL) {
                        id->seekbuf = malloc(SEEK_BUFFER_SIZE);
-                       if (id->seekbuf == NULL)
+                       if (id->seekbuf == NULL) {
+                               dbg("error malloc");
                                return NULL;
+                       }
                }
 
                /* check if we need to read */
                if ((off < id->seekbuf_off) || ((off + len) > (id->seekbuf_off + id->seekbuf_len))) {
                        dbg("read seekbuf off:0x%llx len:0x%zx", (unsigned long long) off, len);
-                       if (lseek(id->fd, off, SEEK_SET) == -1)
+                       if (lseek(id->fd, off, SEEK_SET) < 0) {
+                               dbg("lseek failed (%s)", strerror(errno));
                                return NULL;
+                       }
                        buf_len = read(id->fd, id->seekbuf, len);
+                       if (buf_len < 0) {
+                               dbg("read failed (%s)", strerror(errno));
+                               return NULL;
+                       }
                        dbg("got 0x%zx (%zi) bytes", buf_len, buf_len);
                        id->seekbuf_off = off;
                        id->seekbuf_len = buf_len;
index a82b221..84f8fb6 100644 (file)
@@ -23,7 +23,7 @@
 
 #include <stdint.h>
 
-#define VOLUME_ID_VERSION              47
+#define VOLUME_ID_VERSION              48
 
 #define VOLUME_ID_LABEL_SIZE           64
 #define VOLUME_ID_UUID_SIZE            36