If the user attemps to create a 512MB cluster, we need to adjust the
defaults to avoid a 32-bit overflow of s_blocks_per_group. Also check
to make sure that the caller of ext2fs_initialize() has not given a
value of s_clusters_per_group that would result in an overflow of
s_blocks_per_group.
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
---
lib/ext2fs/initialize.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c
index b0c15d2..5afdc27 100644
--- a/lib/ext2fs/initialize.c
+++ b/lib/ext2fs/initialize.c
@@ -207,6 +207,8 @@ errcode_t ext2fs_initialize(const char *name, int flags,
super->s_log_block_size;
if (bigalloc_flag) {
+ unsigned long long bpg;
+
if (param->s_blocks_per_group &&
param->s_clusters_per_group &&
((param->s_clusters_per_group * EXT2FS_CLUSTER_RATIO(fs)) !=
@@ -220,12 +222,19 @@ errcode_t ext2fs_initialize(const char *name, int flags,
super->s_clusters_per_group =
param->s_blocks_per_group /
EXT2FS_CLUSTER_RATIO(fs);
- else
+ else if (super->s_log_cluster_size + 15 < 32)
super->s_clusters_per_group = fs->blocksize * 8;
+ else
+ super->s_clusters_per_group = (fs->blocksize - 1) * 8;
if (super->s_clusters_per_group > EXT2_MAX_CLUSTERS_PER_GROUP(super))
super->s_clusters_per_group = EXT2_MAX_CLUSTERS_PER_GROUP(super);
- super->s_blocks_per_group = EXT2FS_C2B(fs,
- super->s_clusters_per_group);
+ bpg = EXT2FS_C2B(fs,
+ (unsigned long long) super->s_clusters_per_group);
+ if (bpg >= (((unsigned long long) 1) << 32)) {
+ retval = EXT2_ET_INVALID_ARGUMENT;
+ goto cleanup;
+ }
+ super->s_blocks_per_group = bpg;
} else {
set_field(s_blocks_per_group, fs->blocksize * 8);
if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super))
--
1.7.12.rc0.22.gcdd159b
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
