Description

In the Linux kernel, the following vulnerability has been resolved: stmmac: Clear variable when destroying workqueue Currently when suspending driver and stopping workqueue it is checked whether workqueue is not NULL and if so, it is destroyed. Function destroy_workqueue() does drain queue and does clear variable, but it does not set workqueue variable to NULL. This can cause kernel/module panic if code attempts to clear workqueue that was not initialized. This scenario is possible when resuming suspended driver in stmmac_resume(), because there is no handling for failed stmmac_hw_setup(), which can fail and return if DMA engine has failed to initialize, and workqueue is initialized after DMA engine. Should DMA engine fail to initialize, resume will proceed normally, but interface won't work and TX queue will eventually timeout, causing 'Reset adapter' error. This then does destroy workqueue during reset process. And since workqueue is initialized after DMA engine and can be skipped, it will cause kernel/module panic. To secure against this possible crash, set workqueue variable to NULL when destroying workqueue. Log/backtrace from crash goes as follows: [88.031977]------------[ cut here ]------------ [88.031985]NETDEV WATCHDOG: eth0 (sxgmac): transmit queue 1 timed out [88.032017]WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:477 dev_watchdog+0x390/0x398 <Skipping backtrace for watchdog timeout> [88.032251]---[ end trace e70de432e4d5c2c0 ]--- [88.032282]sxgmac 16d88000.ethernet eth0: Reset adapter. [88.036359]------------[ cut here ]------------ [88.036519]Call trace: [88.036523] flush_workqueue+0x3e4/0x430 [88.036528] drain_workqueue+0xc4/0x160 [88.036533] destroy_workqueue+0x40/0x270 [88.036537] stmmac_fpe_stop_wq+0x4c/0x70 [88.036541] stmmac_release+0x278/0x280 [88.036546] __dev_close_many+0xcc/0x158 [88.036551] dev_close_many+0xbc/0x190 [88.036555] dev_close.part.0+0x70/0xc0 [88.036560] dev_close+0x24/0x30 [88.036564] stmmac_service_task+0x110/0x140 [88.036569] process_one_work+0x1d8/0x4a0 [88.036573] worker_thread+0x54/0x408 [88.036578] kthread+0x164/0x170 [88.036583] ret_from_fork+0x10/0x20 [88.036588]---[ end trace e70de432e4d5c2c1 ]--- [88.036597]Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004

Severity

 

CVSS Version 3.x CVSS Version 2.0

CVSS 3.x Severity and Metrics:

NIST: NVD

Base Score:  N/A

NVD assessment not yet provided.

NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have not published a CVSS score for this CVE at this time. NVD Analysts use publicly available information at the time of analysis to associate CVSS vector strings.

CVSS 2.0 Severity and Metrics:

NIST: NVD

Base Score: N/A

NVD assessment not yet provided.

NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have not published a CVSS score for this CVE at this time. NVD Analysts use publicly available information at the time of analysis to associate CVSS vector strings.

In the Linux kernel, the following vulnerability has been resolved:

stmmac: Clear variable when destroying workqueue

Currently when suspending driver and stopping workqueue it is checked whether
workqueue is not NULL and if so, it is destroyed.
Function destroy_workqueue() does drain queue and does clear variable, but
it does not set workqueue variable to NULL. This can cause kernel/module
panic if code attempts to clear workqueue that was not initialized.

This scenario is possible when resum

kernel.org https://git.kernel.org/stable/c/17ccd9798fe0beda3db212cfa3ebe373f605cbd6 [No types assigned]

kernel.org https://git.kernel.org/stable/c/699b103e48ce32d03fc86c35b37ee8ae4288c7e3 [No types assigned]

kernel.org https://git.kernel.org/stable/c/8af411bbba1f457c33734795f024d0ef26d0963f [No types assigned]

kernel.org https://git.kernel.org/stable/c/8e99556301172465c8fe33c7f78c39a3d4ce8462 [No types assigned]

kernel.org https://git.kernel.org/stable/c/f72cf22dccc94038cbbaa1029cb575bf52e5cbc8 [No types assigned]