evm: fix writing <securityfs>/evm overflow

[ Upstream commit 49219d9b8785ba712575c40e48ce0f7461254626 ]

EVM_SETUP_COMPLETE is defined as 0x80000000, which is larger than INT_MAX.
The "-fno-strict-overflow" compiler option properly prevents signaling
EVM that the EVM policy setup is complete.  Define and read an unsigned
int.

Fixes: f00d797507 ("EVM: Allow userspace to signal an RSA key has been loaded")
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Mimi Zohar 2021-04-26 18:13:45 -04:00 committed by Greg Kroah-Hartman
parent c7dbb2a67b
commit 8657d0d57d

View File

@ -71,12 +71,13 @@ static ssize_t evm_read_key(struct file *filp, char __user *buf,
static ssize_t evm_write_key(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
int i, ret;
unsigned int i;
int ret;
if (!capable(CAP_SYS_ADMIN) || (evm_initialized & EVM_SETUP_COMPLETE))
return -EPERM;
ret = kstrtoint_from_user(buf, count, 0, &i);
ret = kstrtouint_from_user(buf, count, 0, &i);
if (ret)
return ret;