CVE ID:	CVE-2024-26802
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 [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
Test IDs:	None available
Cross References:	Common Vulnerability Exposure (CVE) ID: CVE-2024-26802 https://git.kernel.org/stable/c/17ccd9798fe0beda3db212cfa3ebe373f605cbd6 https://git.kernel.org/stable/c/17ccd9798fe0beda3db212cfa3ebe373f605cbd6 https://git.kernel.org/stable/c/699b103e48ce32d03fc86c35b37ee8ae4288c7e3 https://git.kernel.org/stable/c/699b103e48ce32d03fc86c35b37ee8ae4288c7e3 https://git.kernel.org/stable/c/8af411bbba1f457c33734795f024d0ef26d0963f https://git.kernel.org/stable/c/8af411bbba1f457c33734795f024d0ef26d0963f https://git.kernel.org/stable/c/8e99556301172465c8fe33c7f78c39a3d4ce8462 https://git.kernel.org/stable/c/8e99556301172465c8fe33c7f78c39a3d4ce8462 https://git.kernel.org/stable/c/f72cf22dccc94038cbbaa1029cb575bf52e5cbc8 https://git.kernel.org/stable/c/f72cf22dccc94038cbbaa1029cb575bf52e5cbc8