lsm: convert security_setselfattr() to use memdup_user()

As suggested by the kernel test robot, memdup_user() is a better
option than the combo of kmalloc()/copy_from_user().

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310270805.2ArE52i5-lkp@intel.com/
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Paul Moore 2023-11-01 18:42:12 -04:00
parent 4179320229
commit 9ba8802c8b

View File

@ -4011,14 +4011,9 @@ int security_setselfattr(unsigned int attr, struct lsm_ctx __user *uctx,
if (size > PAGE_SIZE)
return -E2BIG;
lctx = kmalloc(size, GFP_KERNEL);
if (lctx == NULL)
return -ENOMEM;
if (copy_from_user(lctx, uctx, size)) {
rc = -EFAULT;
goto free_out;
}
lctx = memdup_user(uctx, size);
if (IS_ERR(lctx))
return PTR_ERR(lctx);
if (size < lctx->len || size < lctx->ctx_len + sizeof(*lctx) ||
lctx->len < lctx->ctx_len + sizeof(*lctx)) {