binfmt_flat: don't use __put_user()

... and check the return value

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2020-02-19 09:32:55 -05:00
parent 0abb013e2e
commit 8861fd576e

View File

@ -138,35 +138,40 @@ static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start
current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
sp = (unsigned long __user *)current->mm->start_stack;
__put_user(bprm->argc, sp++);
if (put_user(bprm->argc, sp++))
return -EFAULT;
if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) {
unsigned long argv, envp;
argv = (unsigned long)(sp + 2);
envp = (unsigned long)(sp + 2 + bprm->argc + 1);
__put_user(argv, sp++);
__put_user(envp, sp++);
if (put_user(argv, sp++) || put_user(envp, sp++))
return -EFAULT;
}
current->mm->arg_start = (unsigned long)p;
for (i = bprm->argc; i > 0; i--) {
__put_user((unsigned long)p, sp++);
if (put_user((unsigned long)p, sp++))
return -EFAULT;
len = strnlen_user(p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
__put_user(0, sp++);
if (put_user(0, sp++))
return -EFAULT;
current->mm->arg_end = (unsigned long)p;
current->mm->env_start = (unsigned long) p;
for (i = bprm->envc; i > 0; i--) {
__put_user((unsigned long)p, sp++);
if (put_user((unsigned long)p, sp++))
return -EFAULT;
len = strnlen_user(p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
__put_user(0, sp++);
if (put_user(0, sp++))
return -EFAULT;
current->mm->env_end = (unsigned long)p;
return 0;
@ -998,7 +1003,8 @@ static int load_flat_binary(struct linux_binprm *bprm)
unsigned long __user *sp;
current->mm->start_stack -= sizeof(unsigned long);
sp = (unsigned long __user *)current->mm->start_stack;
__put_user(start_addr, sp);
if (put_user(start_addr, sp))
return -EFAULT;
start_addr = libinfo.lib_list[i].entry;
}
}