]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
USB: cdc-acm: fix unprivileged TIOCCSERIAL
authorJohan Hovold <johan@kernel.org>
Thu, 8 Apr 2021 13:16:01 +0000 (15:16 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 9 Apr 2021 14:08:27 +0000 (16:08 +0200)
commitdd5619582d60007139f0447382d2839f4f9e339b
tree757e2017fa0e57e19ac5f2f24039196e7b87088f
parent729f7955cb987c5b7d7e54c87c5ad71c789934f7
USB: cdc-acm: fix unprivileged TIOCCSERIAL

TIOCSSERIAL is a horrid, underspecified, legacy interface which for most
serial devices is only useful for setting the close_delay and
closing_wait parameters.

A non-privileged user has only ever been able to set the since long
deprecated ASYNC_SPD flags and trying to change any other *supported*
feature should result in -EPERM being returned. Setting the current
values for any supported features should return success.

Fix the cdc-acm implementation which instead indicated that the
TIOCSSERIAL ioctl was not even implemented when a non-privileged user
set the current values.

Fixes: ba2d8ce9db0a ("cdc-acm: implement TIOCSSERIAL to avoid blocking close(2)")
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210408131602.27956-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/class/cdc-acm.c