Messages in this thread | | | Subject | Re: [PATCH] SELinux: Measure state and hash of policy using IMA | From | Lakshmi Ramasubramanian <> | Date | Mon, 24 Aug 2020 07:35:55 -0700 |
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On 8/24/20 7:00 AM, Stephen Smalley wrote: > On Fri, Aug 21, 2020 at 9:00 PM Lakshmi Ramasubramanian
> >> +int security_read_policy_kernel(struct selinux_state *state, >> + void **data, size_t *len) >> +{ >> + int rc; >> + >> + rc = security_read_policy_len(state, len); >> + if (rc) >> + return rc; >> + >> + *data = vmalloc(*len); >> + if (!*data) >> + return -ENOMEM; >> >> + return security_read_selinux_policy(state, data, len); >> } > > See the discussion here: > https://lore.kernel.org/selinux/20200824113015.1375857-1-omosnace@redhat.com/T/#t > > In order for this to be safe, you need to ensure that all callers of > security_read_policy_kernel() have taken fsi->mutex in selinuxfs and > any use of security_read_policy_len() occurs while holding the mutex. > Otherwise, the length can change between security_read_policy_len() > and security_read_selinux_policy() if policy is reloaded. >
Thanks. I'll make this change.
-lakshmi
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