Current tty-ldisc module loading logic within tty_ldisc_get()
is prone to mislead beginner that the module is able to be loaded
by a user without capability CAP_SYS_MODULE, add comments and
optimize the logic to make it easy to undertand.
Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
---
drivers/tty/tty_ldisc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 3f68e213df1f..faa125f32110 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -150,7 +150,11 @@ static struct tty_ldisc *tty_ldisc_get(struct tty_struct *tty, int disc)
*/
ldops = get_ldops(disc);
if (IS_ERR(ldops)) {
- if (!capable(CAP_SYS_MODULE) && !tty_ldisc_autoload)
+ /*
+ * Always request tty-ldisc module regardless of user's
+ * CAP_SYS_MODULE if autoload is enabled.
+ */
+ if (!tty_ldisc_autoload && !capable(CAP_SYS_MODULE))
return ERR_PTR(-EPERM);
request_module("tty-ldisc-%d", disc);
ldops = get_ldops(disc);
--
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