From fccd6134d5addf2be1407e3250efdc854b5c5d8a Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Thu, 8 Aug 2019 16:21:19 +0200 Subject: usb: cdc-acm: make sure a refcount is taken early enough commit c52873e5a1ef72f845526d9f6a50704433f9c625 upstream. destroy() will decrement the refcount on the interface, so that it needs to be taken so early that it never undercounts. Fixes: 7fb57a019f94e ("USB: cdc-acm: Fix potential deadlock (lockdep warning)") Cc: stable Reported-and-tested-by: syzbot+1b2449b7b5dc240d107a@syzkaller.appspotmail.com Signed-off-by: Oliver Neukum Link: https://lore.kernel.org/r/20190808142119.7998-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/cdc-acm.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'drivers/usb/class/cdc-acm.c') diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 8d4d46f3fd16..b2edbd4bf8c4 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1264,10 +1264,6 @@ made_compressed_probe: if (acm == NULL) goto alloc_fail; - minor = acm_alloc_minor(acm); - if (minor < 0) - goto alloc_fail1; - ctrlsize = usb_endpoint_maxp(epctrl); readsize = usb_endpoint_maxp(epread) * (quirks == SINGLE_RX_URB ? 1 : 2); @@ -1275,6 +1271,13 @@ made_compressed_probe: acm->writesize = usb_endpoint_maxp(epwrite) * 20; acm->control = control_interface; acm->data = data_interface; + + usb_get_intf(acm->control); /* undone in destruct() */ + + minor = acm_alloc_minor(acm); + if (minor < 0) + goto alloc_fail1; + acm->minor = minor; acm->dev = usb_dev; if (h.usb_cdc_acm_descriptor) @@ -1420,7 +1423,6 @@ skip_countries: usb_driver_claim_interface(&acm_driver, data_interface, acm); usb_set_intfdata(data_interface, acm); - usb_get_intf(control_interface); tty_dev = tty_port_register_device(&acm->port, acm_tty_driver, minor, &control_interface->dev); if (IS_ERR(tty_dev)) { -- cgit v1.2.3 From 7d09cc7bbe80c2f4208daa5e306572ca944af0e3 Mon Sep 17 00:00:00 2001 From: Anthony Mallet Date: Thu, 12 Mar 2020 14:31:00 +0100 Subject: USB: cdc-acm: fix close_delay and closing_wait units in TIOCSSERIAL [ Upstream commit 633e2b2ded739a34bd0fb1d8b5b871f7e489ea29 ] close_delay and closing_wait are specified in hundredth of a second but stored internally in jiffies. Use the jiffies_to_msecs() and msecs_to_jiffies() functions to convert from each other. Signed-off-by: Anthony Mallet Cc: stable Link: https://lore.kernel.org/r/20200312133101.7096-1-anthony.mallet@laas.fr Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/class/cdc-acm.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'drivers/usb/class/cdc-acm.c') diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index b2edbd4bf8c4..9fd1cd99aa97 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -828,10 +828,10 @@ static int get_serial_info(struct acm *acm, struct serial_struct __user *info) tmp.flags = ASYNC_LOW_LATENCY; tmp.xmit_fifo_size = acm->writesize; tmp.baud_base = le32_to_cpu(acm->line.dwDTERate); - tmp.close_delay = acm->port.close_delay / 10; + tmp.close_delay = jiffies_to_msecs(acm->port.close_delay) / 10; tmp.closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? ASYNC_CLOSING_WAIT_NONE : - acm->port.closing_wait / 10; + jiffies_to_msecs(acm->port.closing_wait) / 10; if (copy_to_user(info, &tmp, sizeof(tmp))) return -EFAULT; @@ -849,9 +849,10 @@ static int set_serial_info(struct acm *acm, if (copy_from_user(&new_serial, newinfo, sizeof(new_serial))) return -EFAULT; - close_delay = new_serial.close_delay * 10; + close_delay = msecs_to_jiffies(new_serial.close_delay * 10); closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ? - ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10; + ASYNC_CLOSING_WAIT_NONE : + msecs_to_jiffies(new_serial.closing_wait * 10); mutex_lock(&acm->port.mutex); -- cgit v1.2.3 From 8e22289c9f58b2126f923e0f4e3cb23db9b8f872 Mon Sep 17 00:00:00 2001 From: Anthony Mallet Date: Thu, 12 Mar 2020 14:31:01 +0100 Subject: USB: cdc-acm: fix rounding error in TIOCSSERIAL [ Upstream commit b401f8c4f492cbf74f3f59c9141e5be3071071bb ] By default, tty_port_init() initializes those parameters to a multiple of HZ. For instance in line 69 of tty_port.c: port->close_delay = (50 * HZ) / 100; https://github.com/torvalds/linux/blob/master/drivers/tty/tty_port.c#L69 With e.g. CONFIG_HZ = 250 (as this is the case for Ubuntu 18.04 linux-image-4.15.0-37-generic), the default setting for close_delay is thus 125. When ioctl(fd, TIOCGSERIAL, &s) is executed, the setting returned in user space is '12' (125/10). When ioctl(fd, TIOCSSERIAL, &s) is then executed with the same setting '12', the value is interpreted as '120' which is different from the current setting and a EPERM error may be raised by set_serial_info() if !CAP_SYS_ADMIN. https://github.com/torvalds/linux/blob/master/drivers/usb/class/cdc-acm.c#L919 Fixes: ba2d8ce9db0a6 ("cdc-acm: implement TIOCSSERIAL to avoid blocking close(2)") Signed-off-by: Anthony Mallet Cc: stable Link: https://lore.kernel.org/r/20200312133101.7096-2-anthony.mallet@laas.fr Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/class/cdc-acm.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) (limited to 'drivers/usb/class/cdc-acm.c') diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 9fd1cd99aa97..13df3c8cd7bf 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -844,6 +844,7 @@ static int set_serial_info(struct acm *acm, { struct serial_struct new_serial; unsigned int closing_wait, close_delay; + unsigned int old_closing_wait, old_close_delay; int retval = 0; if (copy_from_user(&new_serial, newinfo, sizeof(new_serial))) @@ -854,18 +855,24 @@ static int set_serial_info(struct acm *acm, ASYNC_CLOSING_WAIT_NONE : msecs_to_jiffies(new_serial.closing_wait * 10); + /* we must redo the rounding here, so that the values match */ + old_close_delay = jiffies_to_msecs(acm->port.close_delay) / 10; + old_closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? + ASYNC_CLOSING_WAIT_NONE : + jiffies_to_msecs(acm->port.closing_wait) / 10; + mutex_lock(&acm->port.mutex); - if (!capable(CAP_SYS_ADMIN)) { - if ((close_delay != acm->port.close_delay) || - (closing_wait != acm->port.closing_wait)) + if ((new_serial.close_delay != old_close_delay) || + (new_serial.closing_wait != old_closing_wait)) { + if (!capable(CAP_SYS_ADMIN)) retval = -EPERM; - else - retval = -EOPNOTSUPP; - } else { - acm->port.close_delay = close_delay; - acm->port.closing_wait = closing_wait; - } + else { + acm->port.close_delay = close_delay; + acm->port.closing_wait = closing_wait; + } + } else + retval = -EOPNOTSUPP; mutex_unlock(&acm->port.mutex); return retval; -- cgit v1.2.3 From 4826a0bef66e71ecdf78c9748375932f5c2073cc Mon Sep 17 00:00:00 2001 From: Matthias Reichl Date: Fri, 27 Mar 2020 16:03:50 +0100 Subject: USB: cdc-acm: restore capability check order commit 62d65bdd9d05158aa2547f8ef72375535f3bc6e3 upstream. commit b401f8c4f492c ("USB: cdc-acm: fix rounding error in TIOCSSERIAL") introduced a regression by changing the order of capability and close settings change checks. When running with CAP_SYS_ADMIN setting the close settings to the values already set resulted in -EOPNOTSUPP. Fix this by changing the check order back to how it was before. Fixes: b401f8c4f492c ("USB: cdc-acm: fix rounding error in TIOCSSERIAL") Cc: Anthony Mallet Cc: stable Cc: Oliver Neukum Signed-off-by: Matthias Reichl Link: https://lore.kernel.org/r/20200327150350.3657-1-hias@horus.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/cdc-acm.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'drivers/usb/class/cdc-acm.c') diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 13df3c8cd7bf..5b0bffba4aac 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -863,16 +863,16 @@ static int set_serial_info(struct acm *acm, mutex_lock(&acm->port.mutex); - if ((new_serial.close_delay != old_close_delay) || - (new_serial.closing_wait != old_closing_wait)) { - if (!capable(CAP_SYS_ADMIN)) + if (!capable(CAP_SYS_ADMIN)) { + if ((new_serial.close_delay != old_close_delay) || + (new_serial.closing_wait != old_closing_wait)) retval = -EPERM; - else { - acm->port.close_delay = close_delay; - acm->port.closing_wait = closing_wait; - } - } else - retval = -EOPNOTSUPP; + else + retval = -EOPNOTSUPP; + } else { + acm->port.close_delay = close_delay; + acm->port.closing_wait = closing_wait; + } mutex_unlock(&acm->port.mutex); return retval; -- cgit v1.2.3