commit b41c1fa155ba56d125885b0191aabaf3c508d0a3 upstream.
TIOCGSERIAL is an ioctl. Thus it must be atomic. It returns
two values. Racing with set_serial it can return an inconsistent
result. The mutex must be taken.
In terms of logic the bug is as old as the driver. In terms of
code it goes back to the conversion to the get_serial and
set_serial methods.
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@kernel.org>
Fixes: 99f75a1fcd865 ("cdc-acm: switch to ->[sg]et_serial()")
Link: https://lore.kernel.org/r/20240912141916.1044393-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0b00583ecacb0b51712a5ecd34cf7e6684307c67 upstream.
USB_DEVICE(0x1901, 0x0006) may send data before cdc_acm is ready, which
may be misinterpreted in the default N_TTY line discipline.
Signed-off-by: Ian Ray <ian.ray@gehealthcare.com>
Acked-by: Oliver Neuku <oneukum@suse.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20240814072905.2501-1-ian.ray@gehealthcare.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 66aad7d8d3ec5a3a8ec2023841bcec2ded5f65c9 ]
In ACM support for sending breaks to devices is optional.
If a device says that it doenot support sending breaks,
the host must respect that.
Given the number of optional features providing tty operations
for each combination is not practical and errors need to be
returned dynamically if unsupported features are requested.
In case a device does not support break, we want the tty layer
to treat that like it treats drivers that statically cannot
support sending a break. It ignores the inability and does nothing.
This patch uses EOPNOTSUPP to indicate that.
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Fixes: 9e98966c7bb94 ("tty: rework break handling")
Link: https://lore.kernel.org/r/20231207132639.18250-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
