diff options
| -rw-r--r-- | kernel/entry/syscall_user_dispatch.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/kernel/entry/syscall_user_dispatch.c b/kernel/entry/syscall_user_dispatch.c index 22396b234854..7f2add43672d 100644 --- a/kernel/entry/syscall_user_dispatch.c +++ b/kernel/entry/syscall_user_dispatch.c @@ -87,7 +87,16 @@ static int task_set_syscall_user_dispatch(struct task_struct *task, unsigned lon if (offset && offset + len <= offset) return -EINVAL; - if (selector && !access_ok(selector, sizeof(*selector))) + /* + * access_ok() will clear memory tags for tagged addresses + * if current has memory tagging enabled. + + * To enable a tracer to set a tracees selector the + * selector address must be untagged for access_ok(), + * otherwise an untagged tracer will always fail to set a + * tagged tracees selector. + */ + if (selector && !access_ok(untagged_addr(selector), sizeof(*selector))) return -EFAULT; break; |