On 8/24/20 7:00 AM, Stephen Smalley wrote:
+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@xxxxxxxxxx/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.
"struct selinux_fs_info" is available when calling security_read_policy_kernel() - currently in measure.c.
Only "struct selinux_state" is. Is Ondrej's re-try approach I need to use to workaround policy reload issue? thanks, -lakshmi
