Make use of the struct_size() helper instead of an open-coded version, in order to avoid any potential type mistakes or integer overflows that, in the worst scenario, could lead to heap overflows. Also, address the following sparse warnings: fs/verity/measure.c:48:9: warning: using sizeof on a flexible structure fs/verity/measure.c:52:38: warning: using sizeof on a flexible structure Signed-off-by: Zhang Jianhua <chris.zjh@xxxxxxxxxx> --- fs/verity/measure.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/verity/measure.c b/fs/verity/measure.c index e99c00350c28..4a388116d0de 100644 --- a/fs/verity/measure.c +++ b/fs/verity/measure.c @@ -27,6 +27,7 @@ int fsverity_ioctl_measure(struct file *filp, void __user *_uarg) const struct fsverity_info *vi; const struct fsverity_hash_alg *hash_alg; struct fsverity_digest arg; + size_t arg_size = struct_size(&arg, digest, 0); vi = fsverity_get_info(inode); if (!vi) @@ -44,11 +45,11 @@ int fsverity_ioctl_measure(struct file *filp, void __user *_uarg) if (arg.digest_size < hash_alg->digest_size) return -EOVERFLOW; - memset(&arg, 0, sizeof(arg)); + memset(&arg, 0, arg_size); arg.digest_algorithm = hash_alg - fsverity_hash_algs; arg.digest_size = hash_alg->digest_size; - if (copy_to_user(uarg, &arg, sizeof(arg))) + if (copy_to_user(uarg, &arg, arg_size)) return -EFAULT; if (copy_to_user(uarg->digest, vi->file_digest, hash_alg->digest_size)) -- 2.31.0
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