| Message ID | 20210429195332.310697-1-zohar@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | evm: fix writing <securityfs>/evm overflow | expand |
On 4/29/21 3:53 PM, Mimi Zohar wrote: > 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: f00d79750712 ("EVM: Allow userspace to signal an RSA key has been > loaded") > Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Tested-by: Stefan Berger <stefanb@linux.ibm.com> > --- > security/integrity/evm/evm_secfs.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/security/integrity/evm/evm_secfs.c b/security/integrity/evm/evm_secfs.c > index bbc85637e18b..0007d3362754 100644 > --- a/security/integrity/evm/evm_secfs.c > +++ b/security/integrity/evm/evm_secfs.c > @@ -66,12 +66,13 @@ 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;
diff --git a/security/integrity/evm/evm_secfs.c b/security/integrity/evm/evm_secfs.c index bbc85637e18b..0007d3362754 100644 --- a/security/integrity/evm/evm_secfs.c +++ b/security/integrity/evm/evm_secfs.c @@ -66,12 +66,13 @@ 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;
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: f00d79750712 ("EVM: Allow userspace to signal an RSA key has been loaded") Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> --- security/integrity/evm/evm_secfs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)