From cb96faa7de7251731097b53d3f50a96160aa34ee Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 16 May 2022 10:03:19 +0200 Subject: [PATCH] 5.4-stable patches added patches: tty-n_gsm-fix-mux-activation-issues-in-gsm_config.patch usb-cdc-wdm-fix-reading-stuck-on-device-close.patch --- queue-5.4/series | 2 + ...-mux-activation-issues-in-gsm_config.patch | 60 +++++++++++++++++++ ...dm-fix-reading-stuck-on-device-close.patch | 56 +++++++++++++++++ 3 files changed, 118 insertions(+) create mode 100644 queue-5.4/tty-n_gsm-fix-mux-activation-issues-in-gsm_config.patch create mode 100644 queue-5.4/usb-cdc-wdm-fix-reading-stuck-on-device-close.patch diff --git a/queue-5.4/series b/queue-5.4/series index 6b42920e7e7..a474f2775bb 100644 --- a/queue-5.4/series +++ b/queue-5.4/series @@ -22,3 +22,5 @@ asoc-ops-validate-input-values-in-snd_soc_put_volsw_.patch s390-disable-warray-bounds.patch net-emaclite-don-t-advertise-1000base-t-and-do-auto-.patch tcp-resalt-the-secret-every-10-seconds.patch +tty-n_gsm-fix-mux-activation-issues-in-gsm_config.patch +usb-cdc-wdm-fix-reading-stuck-on-device-close.patch diff --git a/queue-5.4/tty-n_gsm-fix-mux-activation-issues-in-gsm_config.patch b/queue-5.4/tty-n_gsm-fix-mux-activation-issues-in-gsm_config.patch new file mode 100644 index 00000000000..fda2096a105 --- /dev/null +++ b/queue-5.4/tty-n_gsm-fix-mux-activation-issues-in-gsm_config.patch @@ -0,0 +1,60 @@ +From edd5f60c340086891fab094ad61270d6c80f9ca4 Mon Sep 17 00:00:00 2001 +From: Daniel Starke +Date: Wed, 4 May 2022 10:17:32 +0200 +Subject: tty: n_gsm: fix mux activation issues in gsm_config() + +From: Daniel Starke + +commit edd5f60c340086891fab094ad61270d6c80f9ca4 upstream. + +The current implementation activates the mux if it was restarted and opens +the control channel if the mux was previously closed and we are now acting +as initiator instead of responder, which is the default setting. +This has two issues. +1) No mux is activated if we keep all default values and only switch to +initiator. The control channel is not allocated but will be opened next +which results in a NULL pointer dereference. +2) Switching the configuration after it was once configured while keeping +the initiator value the same will not reopen the control channel if it was +closed due to parameter incompatibilities. The mux remains dead. + +Fix 1) by always activating the mux if it is dead after configuration. +Fix 2) by always opening the control channel after mux activation. + +Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") +Cc: stable@vger.kernel.org +Signed-off-by: Daniel Starke +Link: https://lore.kernel.org/r/20220504081733.3494-2-daniel.starke@siemens.com +Signed-off-by: Greg Kroah-Hartman +--- + drivers/tty/n_gsm.c | 12 ++++++++---- + 1 file changed, 8 insertions(+), 4 deletions(-) + +--- a/drivers/tty/n_gsm.c ++++ b/drivers/tty/n_gsm.c +@@ -2259,6 +2259,7 @@ static void gsm_copy_config_values(struc + + static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c) + { ++ int ret = 0; + int need_close = 0; + int need_restart = 0; + +@@ -2334,10 +2335,13 @@ static int gsm_config(struct gsm_mux *gs + * FIXME: We need to separate activation/deactivation from adding + * and removing from the mux array + */ +- if (need_restart) +- gsm_activate_mux(gsm); +- if (gsm->initiator && need_close) +- gsm_dlci_begin_open(gsm->dlci[0]); ++ if (gsm->dead) { ++ ret = gsm_activate_mux(gsm); ++ if (ret) ++ return ret; ++ if (gsm->initiator) ++ gsm_dlci_begin_open(gsm->dlci[0]); ++ } + return 0; + } + diff --git a/queue-5.4/usb-cdc-wdm-fix-reading-stuck-on-device-close.patch b/queue-5.4/usb-cdc-wdm-fix-reading-stuck-on-device-close.patch new file mode 100644 index 00000000000..cdcc75fc68b --- /dev/null +++ b/queue-5.4/usb-cdc-wdm-fix-reading-stuck-on-device-close.patch @@ -0,0 +1,56 @@ +From 01e01f5c89773c600a9f0b32c888de0146066c3a Mon Sep 17 00:00:00 2001 +From: Sergey Ryazanov +Date: Sun, 1 May 2022 20:58:28 +0300 +Subject: usb: cdc-wdm: fix reading stuck on device close + +From: Sergey Ryazanov + +commit 01e01f5c89773c600a9f0b32c888de0146066c3a upstream. + +cdc-wdm tracks whether a response reading request is in-progress and +blocks the next request from being sent until the previous request is +completed. As soon as last user closes the cdc-wdm device file, the +driver cancels any ongoing requests, resets the pending response +counter, but leaves the response reading in-progress flag +(WDM_RESPONDING) untouched. + +So if the user closes the device file during the response receive +request is being performed, no more data will be obtained from the +modem. The request will be cancelled, effectively preventing the +WDM_RESPONDING flag from being reseted. Keeping the flag set will +prevent a new response receive request from being sent, permanently +blocking the read path. The read path will staying blocked until the +module will be reloaded or till the modem will be re-attached. + +This stuck has been observed with a Huawei E3372 modem attached to an +OpenWrt router and using the comgt utility to set up a network +connection. + +Fix this issue by clearing the WDM_RESPONDING flag on the device file +close. + +Without this fix, the device reading stuck can be easily reproduced in a +few connection establishing attempts. With this fix, a load test for +modem connection re-establishing worked for several hours without any +issues. + +Fixes: 922a5eadd5a3 ("usb: cdc-wdm: Fix race between autosuspend and reading from the device") +Signed-off-by: Sergey Ryazanov +Cc: stable +Acked-by: Oliver Neukum +Link: https://lore.kernel.org/r/20220501175828.8185-1-ryazanov.s.a@gmail.com +Signed-off-by: Greg Kroah-Hartman +--- + drivers/usb/class/cdc-wdm.c | 1 + + 1 file changed, 1 insertion(+) + +--- a/drivers/usb/class/cdc-wdm.c ++++ b/drivers/usb/class/cdc-wdm.c +@@ -755,6 +755,7 @@ static int wdm_release(struct inode *ino + poison_urbs(desc); + spin_lock_irq(&desc->iuspin); + desc->resp_count = 0; ++ clear_bit(WDM_RESPONDING, &desc->flags); + spin_unlock_irq(&desc->iuspin); + desc->manage_power(desc->intf, 0); + unpoison_urbs(desc); -- 2.47.3