Some code in the block layer makes potentially huge allocations. Failure
is not completely unexpected there, so avoid aborting qemu and handle
out-of-memory situations gracefully.
This patch addresses the allocations in the qcow2 block driver.
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block/qcow2-cache.c | 12 +++++++++++-
block/qcow2-cluster.c | 28 +++++++++++++++++++++++-----
block/qcow2-refcount.c | 46 ++++++++++++++++++++++++++++++++++++----------
block/qcow2-snapshot.c | 18 +++++++++++++++---
block/qcow2.c | 37 +++++++++++++++++++++++++++++++------
5 files changed, 116 insertions(+), 25 deletions(-)
diff --git a/block/qcow2-cache.c b/block/qcow2-cache.c
index 8ecbb5b..465ef24 100644
--- a/block/qcow2-cache.c
+++ b/block/qcow2-cache.c
@@ -53,10 +53,20 @@ Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int
num_tables)
c->entries = g_malloc0(sizeof(*c->entries) * num_tables);
for (i = 0; i < c->size; i++) {
- c->entries[i].table = qemu_blockalign(bs, s->cluster_size);
+ c->entries[i].table = qemu_try_blockalign(bs, s->cluster_size);
+ if (c->entries[i].table == NULL) {
+ goto fail;
+ }
}
return c;
+
+fail:
+ for (i = 0; i < c->size; i++) {
+ g_free(c->entries[i].table);
+ }
+ g_free(c);
+ return NULL;
}
int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 4208dc0..152f023 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -72,7 +72,11 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t
min_size,
#endif
new_l1_size2 = sizeof(uint64_t) * new_l1_size;
- new_l1_table = g_malloc0(align_offset(new_l1_size2, 512));
+ new_l1_table = g_try_malloc0(align_offset(new_l1_size2, 512));
+ if (new_l1_table == NULL) {
+ return -ENOMEM;
+ }
+
memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
/* write new table (align to cluster) */
@@ -372,7 +376,10 @@ static int coroutine_fn copy_sectors(BlockDriverState *bs,
}
iov.iov_len = n * BDRV_SECTOR_SIZE;
- iov.iov_base = qemu_blockalign(bs, iov.iov_len);
+ iov.iov_base = qemu_try_blockalign(bs, iov.iov_len);
+ if (iov.iov_base == NULL) {
+ return -ENOMEM;
+ }
qemu_iovec_init_external(&qiov, &iov, 1);
@@ -702,7 +709,11 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs,
QCowL2Meta *m)
trace_qcow2_cluster_link_l2(qemu_coroutine_self(), m->nb_clusters);
assert(m->nb_clusters > 0);
- old_cluster = g_malloc(m->nb_clusters * sizeof(uint64_t));
+ old_cluster = g_try_malloc(m->nb_clusters * sizeof(uint64_t));
+ if (old_cluster == NULL) {
+ ret = -ENOMEM;
+ goto err;
+ }
/* copy content of unmodified sectors */
ret = perform_cow(bs, m, &m->cow_start);
@@ -1562,7 +1573,10 @@ static int expand_zero_clusters_in_l1(BlockDriverState
*bs, uint64_t *l1_table,
if (!is_active_l1) {
/* inactive L2 tables require a buffer to be stored in when loading
* them from disk */
- l2_table = qemu_blockalign(bs, s->cluster_size);
+ l2_table = qemu_try_blockalign(bs, s->cluster_size);
+ if (l2_table == NULL) {
+ return -ENOMEM;
+ }
}
for (i = 0; i < l1_size; i++) {
@@ -1740,7 +1754,11 @@ int qcow2_expand_zero_clusters(BlockDriverState *bs)
nb_clusters = size_to_clusters(s, bs->file->total_sectors *
BDRV_SECTOR_SIZE);
- expanded_clusters = g_malloc0((nb_clusters + 7) / 8);
+ expanded_clusters = g_try_malloc0((nb_clusters + 7) / 8);
+ if (expanded_clusters == NULL) {
+ ret = -ENOMEM;
+ goto fail;
+ }
ret = expand_zero_clusters_in_l1(bs, s->l1_table, s->l1_size,
&expanded_clusters, &nb_clusters);
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 9507aef..494a182 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -45,8 +45,12 @@ int qcow2_refcount_init(BlockDriverState *bs)
assert(s->refcount_table_size <= INT_MAX / sizeof(uint64_t));
refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t);
- s->refcount_table = g_malloc(refcount_table_size2);
+ s->refcount_table = g_try_malloc(refcount_table_size2);
+
if (s->refcount_table_size > 0) {
+ if (s->refcount_table == NULL) {
+ goto fail;
+ }
BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_LOAD);
ret = bdrv_pread(bs->file, s->refcount_table_offset,
s->refcount_table, refcount_table_size2);
@@ -343,8 +347,14 @@ static int alloc_refcount_block(BlockDriverState *bs,
uint64_t meta_offset = (blocks_used * refcount_block_clusters) *
s->cluster_size;
uint64_t table_offset = meta_offset + blocks_clusters * s->cluster_size;
- uint16_t *new_blocks = g_malloc0(blocks_clusters * s->cluster_size);
- uint64_t *new_table = g_malloc0(table_size * sizeof(uint64_t));
+ uint64_t *new_table = g_try_malloc0(table_size * sizeof(uint64_t));
+ uint16_t *new_blocks = g_try_malloc0(blocks_clusters * s->cluster_size);
+
+ assert(table_size > 0 && blocks_clusters > 0);
+ if (new_table == NULL || new_blocks == NULL) {
+ ret = -ENOMEM;
+ goto fail_table;
+ }
/* Fill the new refcount table */
memcpy(new_table, s->refcount_table,
@@ -846,7 +856,8 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs,
int64_t l1_table_offset, int l1_size, int addend)
{
BDRVQcowState *s = bs->opaque;
- uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated;
+ uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2;
+ bool l1_allocated = false;
int64_t old_offset, old_l2_offset;
int i, j, l1_modified = 0, nb_csectors, refcount;
int ret;
@@ -861,8 +872,12 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs,
* l1_table_offset when it is the current s->l1_table_offset! Be careful
* when changing this! */
if (l1_table_offset != s->l1_table_offset) {
- l1_table = g_malloc0(align_offset(l1_size2, 512));
- l1_allocated = 1;
+ l1_table = g_try_malloc0(align_offset(l1_size2, 512));
+ if (l1_size2 && l1_table == NULL) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+ l1_allocated = true;
ret = bdrv_pread(bs->file, l1_table_offset, l1_table, l1_size2);
if (ret < 0) {
@@ -874,7 +889,7 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs,
} else {
assert(l1_size == s->l1_size);
l1_table = s->l1_table;
- l1_allocated = 0;
+ l1_allocated = false;
}
for(i = 0; i < l1_size; i++) {
@@ -1196,7 +1211,11 @@ static int check_refcounts_l1(BlockDriverState *bs,
if (l1_size2 == 0) {
l1_table = NULL;
} else {
- l1_table = g_malloc(l1_size2);
+ l1_table = g_try_malloc(l1_size2);
+ if (l1_table == NULL) {
+ ret = -ENOMEM;
+ goto fail;
+ }
if (bdrv_pread(bs->file, l1_table_offset,
l1_table, l1_size2) != l1_size2)
goto fail;
@@ -1500,7 +1519,10 @@ int qcow2_check_refcounts(BlockDriverState *bs,
BdrvCheckResult *res,
return -EFBIG;
}
- refcount_table = g_malloc0(nb_clusters * sizeof(uint16_t));
+ refcount_table = g_try_malloc0(nb_clusters * sizeof(uint16_t));
+ if (nb_clusters && refcount_table == NULL) {
+ return -ENOMEM;
+ }
res->bfi.total_clusters =
size_to_clusters(s, bs->total_sectors * BDRV_SECTOR_SIZE);
@@ -1752,9 +1774,13 @@ int qcow2_check_metadata_overlap(BlockDriverState *bs,
int ign, int64_t offset,
uint64_t l1_ofs = s->snapshots[i].l1_table_offset;
uint32_t l1_sz = s->snapshots[i].l1_size;
uint64_t l1_sz2 = l1_sz * sizeof(uint64_t);
- uint64_t *l1 = g_malloc(l1_sz2);
+ uint64_t *l1 = g_try_malloc(l1_sz2);
int ret;
+ if (l1_sz2 && l1 == NULL) {
+ return -ENOMEM;
+ }
+
ret = bdrv_pread(bs->file, l1_ofs, l1, l1_sz2);
if (ret < 0) {
g_free(l1);
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index 0aa9def..fbd7bee 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -381,7 +381,12 @@ int qcow2_snapshot_create(BlockDriverState *bs,
QEMUSnapshotInfo *sn_info)
sn->l1_table_offset = l1_table_offset;
sn->l1_size = s->l1_size;
- l1_table = g_malloc(s->l1_size * sizeof(uint64_t));
+ l1_table = g_try_malloc(s->l1_size * sizeof(uint64_t));
+ if (s->l1_size && l1_table == NULL) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
for(i = 0; i < s->l1_size; i++) {
l1_table[i] = cpu_to_be64(s->l1_table[i]);
}
@@ -499,7 +504,11 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char
*snapshot_id)
* Decrease the refcount referenced by the old one only when the L1
* table is overwritten.
*/
- sn_l1_table = g_malloc0(cur_l1_bytes);
+ sn_l1_table = g_try_malloc0(cur_l1_bytes);
+ if (cur_l1_bytes && sn_l1_table == NULL) {
+ ret = -ENOMEM;
+ goto fail;
+ }
ret = bdrv_pread(bs->file, sn->l1_table_offset, sn_l1_table, sn_l1_bytes);
if (ret < 0) {
@@ -698,7 +707,10 @@ int qcow2_snapshot_load_tmp(BlockDriverState *bs,
return -EFBIG;
}
new_l1_bytes = sn->l1_size * sizeof(uint64_t);
- new_l1_table = g_malloc0(align_offset(new_l1_bytes, 512));
+ new_l1_table = g_try_malloc0(align_offset(new_l1_bytes, 512));
+ if (new_l1_bytes && new_l1_table == NULL) {
+ return -ENOMEM;
+ }
ret = bdrv_pread(bs->file, sn->l1_table_offset, new_l1_table,
new_l1_bytes);
if (ret < 0) {
diff --git a/block/qcow2.c b/block/qcow2.c
index a4b97e8..1efdd17 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -676,8 +676,13 @@ static int qcow2_open(BlockDriverState *bs, QDict
*options, int flags,
if (s->l1_size > 0) {
- s->l1_table = g_malloc0(
+ s->l1_table = qemu_try_blockalign(bs->file,
align_offset(s->l1_size * sizeof(uint64_t), 512));
+ if (s->l1_size && s->l1_table == NULL) {
+ error_setg(errp, "Could not allocate L1 table");
+ ret = -ENOMEM;
+ goto fail;
+ }
ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table,
s->l1_size * sizeof(uint64_t));
if (ret < 0) {
@@ -692,11 +697,22 @@ static int qcow2_open(BlockDriverState *bs, QDict
*options, int flags,
/* alloc L2 table/refcount block cache */
s->l2_table_cache = qcow2_cache_create(bs, L2_CACHE_SIZE);
s->refcount_block_cache = qcow2_cache_create(bs, REFCOUNT_CACHE_SIZE);
+ if (s->l2_table_cache == NULL || s->refcount_block_cache == NULL) {
+ error_setg(errp, "Could not allocate metadata caches");
+ ret = -ENOMEM;
+ goto fail;
+ }
s->cluster_cache = g_malloc(s->cluster_size);
/* one more sector for decompressed data alignment */
- s->cluster_data = qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS *
s->cluster_size
- + 512);
+ s->cluster_data = qemu_try_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS
+ * s->cluster_size + 512);
+ if (s->cluster_data == NULL) {
+ error_setg(errp, "Could not allocate temporary cluster buffer");
+ ret = -ENOMEM;
+ goto fail;
+ }
+
s->cluster_cache_offset = -1;
s->flags = flags;
@@ -1063,7 +1079,12 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState
*bs, int64_t sector_num,
*/
if (!cluster_data) {
cluster_data =
- qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS *
s->cluster_size);
+ qemu_try_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS
+ * s->cluster_size);
+ if (cluster_data == NULL) {
+ ret = -ENOMEM;
+ goto fail;
+ }
}
assert(cur_nr_sectors <=
@@ -1163,8 +1184,12 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
if (s->crypt_method) {
if (!cluster_data) {
- cluster_data = qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS *
- s->cluster_size);
+ cluster_data = qemu_try_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS
+ * s->cluster_size);
+ if (cluster_data == NULL) {
+ ret = -ENOMEM;
+ goto fail;
+ }
}
assert(hd_qiov.size <=
--
1.8.3.1
