kernel/drivers/usb/class/cdc-wdm.c, branch linux-6.9.y

USB: class: cdc-wdm: Fix CPU lockup caused by excessive log messages

2024-06-21T12:40:11Z

commit 22f00812862564b314784167a89f27b444f82a46 upstream. The syzbot fuzzer found that the interrupt-URB completion callback in the cdc-wdm driver was taking too long, and the driver's immediate resubmission of interrupt URBs with -EPROTO status combined with the dummy-hcd emulation to cause a CPU lockup: cdc_wdm 1-1:1.0: nonzero urb status received: -71 cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz-executor782:6625] CPU#0 Utilization every 4s during lockup: #1: 98% system, 0% softirq, 3% hardirq, 0% idle #2: 98% system, 0% softirq, 3% hardirq, 0% idle #3: 98% system, 0% softirq, 3% hardirq, 0% idle #4: 98% system, 0% softirq, 3% hardirq, 0% idle #5: 98% system, 1% softirq, 3% hardirq, 0% idle Modules linked in: irq event stamp: 73096 hardirqs last enabled at (73095): [] console_emit_next_record kernel/printk/printk.c:2935 [inline] hardirqs last enabled at (73095): [] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994 hardirqs last disabled at (73096): [] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline] hardirqs last disabled at (73096): [] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551 softirqs last enabled at (73048): [] softirq_handle_end kernel/softirq.c:400 [inline] softirqs last enabled at (73048): [] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582 softirqs last disabled at (73043): [] __do_softirq+0x14/0x20 kernel/softirq.c:588 CPU: 0 PID: 6625 Comm: syz-executor782 Tainted: G W 6.10.0-rc2-syzkaller-g8867bbd4a056 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Testing showed that the problem did not occur if the two error messages -- the first two lines above -- were removed; apparently adding material to the kernel log takes a surprisingly large amount of time. In any case, the best approach for preventing these lockups and to avoid spamming the log with thousands of error messages per second is to ratelimit the two dev_err() calls. Therefore we replace them with dev_err_ratelimited(). Signed-off-by: Alan Stern Suggested-by: Greg KH Reported-and-tested-by: syzbot+5f996b83575ef4058638@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-usb/00000000000073d54b061a6a1c65@google.com/ Reported-and-tested-by: syzbot+1b2abad17596ad03dcff@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-usb/000000000000f45085061aa9b37e@google.com/ Fixes: 9908a32e94de ("USB: remove err() macro from usb class drivers") Link: https://lore.kernel.org/linux-usb/40dfa45b-5f21-4eef-a8c1-51a2f320e267@rowland.harvard.edu/ Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/29855215-52f5-4385-b058-91f42c2bee18@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

Revert "usb: cdc-wdm: close race between read and workqueue"

2024-04-18T14:33:28Z

This reverts commit 339f83612f3a569b194680768b22bf113c26a29d. It has been found to cause problems in a number of Chromebook devices, so revert the change until it can be brought back in a safe way. Link: https://lore.kernel.org/r/385a3519-b45d-48c5-a6fd-a3fdb6bec92f@chromium.org Reported-by:: Aleksander Morgado Fixes: 339f83612f3a ("usb: cdc-wdm: close race between read and workqueue") Cc: stable Cc: Oliver Neukum Cc: Bjørn Mork Signed-off-by: Greg Kroah-Hartman

usb: cdc-wdm: close race between read and workqueue

2024-03-26T13:56:33Z

wdm_read() cannot race with itself. However, in service_outstanding_interrupt() it can race with the workqueue, which can be triggered by error handling. Hence we need to make sure that the WDM_RESPONDING flag is not just only set but tested. Fixes: afba937e540c9 ("USB: CDC WDM driver") Cc: stable Signed-off-by: Oliver Neukum Link: https://lore.kernel.org/r/20240314115132.3907-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman

wwan: core: Support slicing in port TX flow of WWAN subsystem

2023-03-18T05:38:31Z

wwan_port_fops_write inputs the SKB parameter to the TX callback of the WWAN device driver. However, the WWAN device (e.g., t7xx) may have an MTU less than the size of SKB, causing the TX buffer to be sliced and copied once more in the WWAN device driver. This patch implements the slicing in the WWAN subsystem and gives the WWAN devices driver the option to slice(by frag_len) or not. By doing so, the additional memory copy is reduced. Meanwhile, this patch gives WWAN devices driver the option to reserve headroom in fragments for the device-specific metadata. Signed-off-by: haozhe chang Reviewed-by: Loic Poulain Link: https://lore.kernel.org/r/20230316095826.181904-1-haozhe.chang@mediatek.com Signed-off-by: Jakub Kicinski

usb: cdc-wdm: Use skb_put_data() instead of skb_put/memcpy pair

2022-09-27T08:36:33Z

Use skb_put_data() instead of skb_put() and memcpy(), which is clear. Signed-off-by: Shang XiaoJing Acked-by: Oliver Neukum Link: https://lore.kernel.org/r/20220927024344.14352-1-shangxiaojing@huawei.com Signed-off-by: Greg Kroah-Hartman

usb: cdc-wdm: fix reading stuck on device close

2022-05-05T20:17:43Z

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

Merge 5.15-rc5 into usb-next

2021-10-11T05:39:38Z

We need the USB fixes in here as well. Signed-off-by: Greg Kroah-Hartman

usb: cdc-wdm: Fix check for WWAN

2021-10-05T11:49:23Z

CONFIG_WWAN_CORE was with CONFIG_WWAN in commit 89212e160b81 ("net: wwan: Fix WWAN config symbols"), but did not update all users of it. Change it back to use CONFIG_WWAN instead. Fixes: 89212e160b81 ("net: wwan: Fix WWAN config symbols") Cc: Signed-off-by: Rikard Falkeborn Acked-by: Oliver Neukum Link: https://lore.kernel.org/r/20210929194547.46954-2-rikard.falkeborn@gmail.com Signed-off-by: Greg Kroah-Hartman

usb: cdc-wdm: Constify static struct wwan_port_ops

2021-10-05T10:58:17Z

The only usage of wdm_wwan_port_ops is to pass its address to wwan_create_port() which takes a pointer to const wwan_port_ops as argument. Make it const to allow the compiler to put it in read-only memory. Signed-off-by: Rikard Falkeborn Acked-by: Oliver Neukum Link: https://lore.kernel.org/r/20210929194547.46954-3-rikard.falkeborn@gmail.com Signed-off-by: Greg Kroah-Hartman

usb: cdc-wdm: fix build error when CONFIG_WWAN_CORE is not set

2021-07-21T08:13:06Z

Gcc report build error as following when CONFIG_WWAN_CORE is not set: x86_64-linux-gnu-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_disconnect': cdc-wdm.c:(.text+0xb2a): undefined reference to `wwan_remove_port' x86_64-linux-gnu-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_in_callback': cdc-wdm.c:(.text+0xf23): undefined reference to `wwan_port_rx' x86_64-linux-gnu-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_wwan_port_stop': cdc-wdm.c:(.text+0x127d): undefined reference to `wwan_port_get_drvdata' x86_64-linux-gnu-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_wwan_port_tx': cdc-wdm.c:(.text+0x12d9): undefined reference to `wwan_port_get_drvdata' x86_64-linux-gnu-ld: cdc-wdm.c:(.text+0x13c1): undefined reference to `wwan_port_txoff' x86_64-linux-gnu-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_wwan_port_start': cdc-wdm.c:(.text+0x13e0): undefined reference to `wwan_port_get_drvdata' x86_64-linux-gnu-ld: cdc-wdm.c:(.text+0x1431): undefined reference to `wwan_port_txon' x86_64-linux-gnu-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_wwan_port_tx_complete': cdc-wdm.c:(.text+0x14a4): undefined reference to `wwan_port_txon' x86_64-linux-gnu-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_create.cold': cdc-wdm.c:(.text.unlikely+0x209): undefined reference to `wwan_create_port' Using CONFIG_WWAN_CORE instead of CONFIG_WWAN to avoid build error. Fixes: cac6fb015f71 ("usb: class: cdc-wdm: WWAN framework integration") Reported-by: Hulk Robot Reviewed-by: Loic Poulain Signed-off-by: Wei Yongjun Link: https://lore.kernel.org/r/20210521021010.2490930-1-weiyongjun1@huawei.com Signed-off-by: Greg Kroah-Hartman