seccomp: Remove bogus __user annotations

stable inclusion
from stable-5.11-rc1
commit fab686eb
bugzilla: 167382
CVE: N/A

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fab686eb0307121e7a2890b6d6c57edd2457863d

-------------------------------------------------

Buffers that are passed to read_actions_logged() and write_actions_logged()
are in kernel memory; the sysctl core takes care of copying from/to
userspace.

Fixes: 32927393 ("sysctl: pass kernel pointers to ->proc_handler")
Reviewed-by: NTyler Hicks <code@tyhicks.com>
Signed-off-by: NJann Horn <jannh@google.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201120170545.1419332-1-jannh@google.comSigned-off-by: NGONG, Ruiqi <gongruiqi1@huawei.com>
Reviewed-by: NXiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

kernel/seccomp.c

@@ -2205,7 +2205,7 @@ static bool seccomp_actions_logged_from_names(u32 *actions_logged, char *names)
 	return true;
 }
 
-static int read_actions_logged(struct ctl_table *ro_table, void __user *buffer,
+static int read_actions_logged(struct ctl_table *ro_table, void *buffer,
 			       size_t *lenp, loff_t *ppos)
 {
 	char names[sizeof(seccomp_actions_avail)];
@@ -2223,7 +2223,7 @@ static int read_actions_logged(struct ctl_table *ro_table, void __user *buffer,
 	return proc_dostring(&table, 0, buffer, lenp, ppos);
 }
 
-static int write_actions_logged(struct ctl_table *ro_table, void __user *buffer,
+static int write_actions_logged(struct ctl_table *ro_table, void *buffer,
 				size_t *lenp, loff_t *ppos, u32 *actions_logged)
 {
 	char names[sizeof(seccomp_actions_avail)];