Merge remote-tracking branch 'stefanha/block' into staging

# By Kevin Wolf
# Via Stefan Hajnoczi
* stefanha/block:
  block: Add hint to -EFBIG error message
  qcow2: Catch some L1 table index overflows

Message-id: 1368543269-29784-1-git-send-email-stefanha@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

4 files changed, 35 insertions, 14 deletions

diff --git a/block.c b/block.c
index aa9a533355..3f87489937 100644
--- a/block.c
+++ b/block.c
@@ -4857,8 +4857,12 @@ void bdrv_img_create(const char *filename, const char *fmt,
             error_setg(errp,"Formatting or formatting option not supported for "
                             "file format '%s'", fmt);
         } else if (ret == -EFBIG) {
-            error_setg(errp, "The image size is too large for file format '%s'",
-                       fmt);
+            const char *cluster_size_hint = "";
+            if (get_option_parameter(create_options, BLOCK_OPT_CLUSTER_SIZE)) {
+                cluster_size_hint = " (try using a larger cluster size)";
+            }
+            error_setg(errp, "The image size is too large for file format '%s'%s",
+                       fmt, cluster_size_hint);
         } else {
             error_setg(errp, "%s: error while creating %s: %s", filename, fmt,
                        strerror(-ret));
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index c71470a3db..76f30e5c26 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -29,12 +29,13 @@
 #include "block/qcow2.h"
 #include "trace.h"
 
-int qcow2_grow_l1_table(BlockDriverState *bs, int min_size, bool exact_size)
+int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
+                        bool exact_size)
 {
     BDRVQcowState *s = bs->opaque;
-    int new_l1_size, new_l1_size2, ret, i;
+    int new_l1_size2, ret, i;
     uint64_t *new_l1_table;
-    int64_t new_l1_table_offset;
+    int64_t new_l1_table_offset, new_l1_size;
     uint8_t data[12];
 
     if (min_size <= s->l1_size)
@@ -53,8 +54,13 @@ int qcow2_grow_l1_table(BlockDriverState *bs, int min_size, bool exact_size)
         }
     }
 
+    if (new_l1_size > INT_MAX) {
+        return -EFBIG;
+    }
+
 #ifdef DEBUG_ALLOC2
-    fprintf(stderr, "grow l1_table from %d to %d\n", s->l1_size, new_l1_size);
+    fprintf(stderr, "grow l1_table from %d to %" PRId64 "\n",
+            s->l1_size, new_l1_size);
 #endif
 
     new_l1_size2 = sizeof(uint64_t) * new_l1_size;
@@ -391,8 +397,8 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
     int *num, uint64_t *cluster_offset)
 {
     BDRVQcowState *s = bs->opaque;
-    unsigned int l1_index, l2_index;
-    uint64_t l2_offset, *l2_table;
+    unsigned int l2_index;
+    uint64_t l1_index, l2_offset, *l2_table;
     int l1_bits, c;
     unsigned int index_in_cluster, nb_clusters;
     uint64_t nb_available, nb_needed;
@@ -507,8 +513,8 @@ static int get_cluster_table(BlockDriverState *bs, uint64_t offset,
                              int *new_l2_index)
 {
     BDRVQcowState *s = bs->opaque;
-    unsigned int l1_index, l2_index;
-    uint64_t l2_offset;
+    unsigned int l2_index;
+    uint64_t l1_index, l2_offset;
     uint64_t *l2_table = NULL;
     int ret;
 
@@ -522,6 +528,7 @@ static int get_cluster_table(BlockDriverState *bs, uint64_t offset,
         }
     }
 
+    assert(l1_index < s->l1_size);
     l2_offset = s->l1_table[l1_index] & L1E_OFFSET_MASK;
 
     /* seek the l2 table of the given l2 offset */
diff --git a/block/qcow2.c b/block/qcow2.c
index 2e346d8c42..0fa5cb29ae 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -307,6 +307,7 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags)
     QemuOpts *opts;
     Error *local_err = NULL;
     uint64_t ext_end;
+    uint64_t l1_vm_state_index;
 
     ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
     if (ret < 0) {
@@ -424,7 +425,14 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags)
 
     /* read the level 1 table */
     s->l1_size = header.l1_size;
-    s->l1_vm_state_index = size_to_l1(s, header.size);
+
+    l1_vm_state_index = size_to_l1(s, header.size);
+    if (l1_vm_state_index > INT_MAX) {
+        ret = -EFBIG;
+        goto fail;
+    }
+    s->l1_vm_state_index = l1_vm_state_index;
+
     /* the L1 table must contain at least enough entries to put
        header.size bytes */
     if (s->l1_size < s->l1_vm_state_index) {
@@ -1480,7 +1488,8 @@ static coroutine_fn int qcow2_co_discard(BlockDriverState *bs,
 static int qcow2_truncate(BlockDriverState *bs, int64_t offset)
 {
     BDRVQcowState *s = bs->opaque;
-    int ret, new_l1_size;
+    int64_t new_l1_size;
+    int ret;
 
     if (offset & 511) {
         error_report("The new size must be a multiple of 512");
diff --git a/block/qcow2.h b/block/qcow2.h
index 94218432f3..6959c6a05f 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -284,7 +284,7 @@ static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
 }
 
-static inline int size_to_l1(BDRVQcowState *s, int64_t size)
+static inline int64_t size_to_l1(BDRVQcowState *s, int64_t size)
 {
     int shift = s->cluster_bits + s->l2_bits;
     return (size + (1ULL << shift) - 1) >> shift;
@@ -360,7 +360,8 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
                           BdrvCheckMode fix);
 
 /* qcow2-cluster.c functions */
-int qcow2_grow_l1_table(BlockDriverState *bs, int min_size, bool exact_size);
+int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
+                        bool exact_size);
 void qcow2_l2_cache_reset(BlockDriverState *bs);
 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
 void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,