Cleanup: move overflow safe alloc code into libsquashfs

There were only a hand full of instances outside libsquashfs that used
the alloc code. In most cases, the thing allocated hat its size derived
from something already in memory anyway, so it is safe to assume its
size fits into a size_t.

At the same time, the opencoded Windows path conversion functions are
all unified into a single helper function.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 11 insertions, 2 deletions

diff --git a/mkfs/mkfs.c b/mkfs/mkfs.c
index 7484618..6ddcdb0 100644
--- a/mkfs/mkfs.c
+++ b/mkfs/mkfs.c
@@ -50,6 +50,7 @@ static int pack_files(sqfs_data_writer_t *data, fstree_t *fs,
 	const char *path;
 	char *node_path;
 	file_info_t *fi;
+	size_t size;
 	int ret;
 
 	if (set_working_dir(opt))
@@ -90,8 +91,16 @@ static int pack_files(sqfs_data_writer_t *data, fstree_t *fs,
 		if (filesize % opt->cfg.block_size)
 			++max_blk_count;
 
-		inode = alloc_flex(sizeof(*inode), sizeof(sqfs_u32),
-				   max_blk_count);
+		if (SZ_MUL_OV(sizeof(sqfs_u32), max_blk_count, &size) ||
+		    SZ_ADD_OV(sizeof(*inode), size, &size)) {
+			fputs("creating file inode: too many blocks\n",
+			      stderr);
+			file->destroy(file);
+			free(node_path);
+			return -1;
+		}
+
+		inode = calloc(1, size);
 		if (inode == NULL) {
 			perror("creating file inode");
 			file->destroy(file);