vvfat: fat_chksum(): fix access above array bounds

[qemu.git] / block.c

diff --git a/block.c b/block.c
index 452ae94eeab9d63b1900a9153d0c83d07270a672..a5514e361ae6e979f53c22e6e8c5b3ff4e6600c8 100644 (file)
--- a/block.c
+++ b/block.c
@@ -739,14 +739,17 @@ int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res)
     return bs->drv->bdrv_check(bs, res);
 }
 
+#define COMMIT_BUF_SECTORS 2048
+
 /* commit COW file into the raw image */
 int bdrv_commit(BlockDriverState *bs)
 {
     BlockDriver *drv = bs->drv;
-    int64_t i, total_sectors;
-    int n, j, ro, open_flags;
+    BlockDriver *backing_drv;
+    int64_t sector, total_sectors;
+    int n, ro, open_flags;
     int ret = 0, rw_ret = 0;
-    unsigned char sector[BDRV_SECTOR_SIZE];
+    uint8_t *buf;
     char filename[1024];
     BlockDriverState *bs_rw, *bs_ro;
 
@@ -760,7 +763,8 @@ int bdrv_commit(BlockDriverState *bs)
     if (bs->backing_hd->keep_read_only) {
         return -EACCES;
     }
-    
+
+    backing_drv = bs->backing_hd->drv;
     ro = bs->backing_hd->read_only;
     strncpy(filename, bs->backing_hd->filename, sizeof(filename));
     open_flags =  bs->backing_hd->open_flags;
@@ -770,12 +774,14 @@ int bdrv_commit(BlockDriverState *bs)
         bdrv_delete(bs->backing_hd);
         bs->backing_hd = NULL;
         bs_rw = bdrv_new("");
-        rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR, drv);
+        rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR,
+            backing_drv);
         if (rw_ret < 0) {
             bdrv_delete(bs_rw);
             /* try to re-open read-only */
             bs_ro = bdrv_new("");
-            ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR, drv);
+            ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
+                backing_drv);
             if (ret < 0) {
                 bdrv_delete(bs_ro);
                 /* drive not functional anymore */
@@ -789,22 +795,20 @@ int bdrv_commit(BlockDriverState *bs)
     }
 
     total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
-    for (i = 0; i < total_sectors;) {
-        if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
-            for(j = 0; j < n; j++) {
-                if (bdrv_read(bs, i, sector, 1) != 0) {
-                    ret = -EIO;
-                    goto ro_cleanup;
-                }
+    buf = qemu_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
 
-                if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
-                    ret = -EIO;
-                    goto ro_cleanup;
-                }
-                i++;
-           }
-       } else {
-            i += n;
+    for (sector = 0; sector < total_sectors; sector += n) {
+        if (drv->bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n)) {
+
+            if (bdrv_read(bs, sector, buf, n) != 0) {
+                ret = -EIO;
+                goto ro_cleanup;
+            }
+
+            if (bdrv_write(bs->backing_hd, sector, buf, n) != 0) {
+                ret = -EIO;
+                goto ro_cleanup;
+            }
         }
     }
 
@@ -821,13 +825,15 @@ int bdrv_commit(BlockDriverState *bs)
         bdrv_flush(bs->backing_hd);
 
 ro_cleanup:
+    qemu_free(buf);
 
     if (ro) {
         /* re-open as RO */
         bdrv_delete(bs->backing_hd);
         bs->backing_hd = NULL;
         bs_ro = bdrv_new("");
-        ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR, drv);
+        ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
+            backing_drv);
         if (ret < 0) {
             bdrv_delete(bs_ro);
             /* drive not functional anymore */
@@ -1476,10 +1482,8 @@ int bdrv_has_zero_init(BlockDriverState *bs)
 {
     assert(bs->drv);
 
-    if (bs->drv->no_zero_init) {
-        return 0;
-    } else if (bs->file) {
-        return bdrv_has_zero_init(bs->file);
+    if (bs->drv->bdrv_has_zero_init) {
+        return bs->drv->bdrv_has_zero_init(bs);
     }
 
     return 1;
@@ -2518,7 +2522,7 @@ int bdrv_is_inserted(BlockDriverState *bs)
     if (!drv)
         return 0;
     if (!drv->bdrv_is_inserted)
-        return 1;
+        return !bs->tray_open;
     ret = drv->bdrv_is_inserted(bs);
     return ret;
 }
@@ -2560,10 +2564,11 @@ int bdrv_eject(BlockDriverState *bs, int eject_flag)
         ret = drv->bdrv_eject(bs, eject_flag);
     }
     if (ret == -ENOTSUP) {
-        if (eject_flag)
-            bdrv_close(bs);
         ret = 0;
     }
+    if (ret >= 0) {
+        bs->tray_open = eject_flag;
+    }
 
     return ret;
 }