In the Linux kernel, the following vulnerability has been resolved: usb: cdns3: fix role switching during resume If the role change while we are suspended, the cdns3 driver switches to the new mode during resume. However, switching to host mode in this context causes a NULL pointer dereference. The host role's start() operation registers a xhci-hcd device, but its probe is deferred while we are in the resume path. The host role's resume() operation assumes the xhci-hcd device is already probed, which is not the case, leading to the dereference. Since the start() operation of the new role is already called, the resume operation can be skipped. So skip the resume operation for the new role if a role switch occurs during resume. Once the resume sequence is complete, the xhci-hcd device can be probed in case of host mode. Unable to handle kernel NULL pointer dereference at virtual address 0000000000000208 Mem abort info: ... Data abort info: ... [0000000000000208] pgd=0000000000000000, p4d=0000000000000000 Internal error: Oops: 0000000096000004 [#1] SMP Modules linked in: CPU: 0 UID: 0 PID: 146 Comm: sh Not tainted 6.19.0-rc7-00013-g6e64f4aabfae-dirty #135 PREEMPT Hardware name: Texas Instruments J7200 EVM (DT) pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : usb_hcd_is_primary_hcd+0x0/0x1c lr : cdns_host_resume+0x24/0x5c ... Call trace: usb_hcd_is_primary_hcd+0x0/0x1c (P) cdns_resume+0x6c/0xbc cdns3_controller_resume.isra.0+0xe8/0x17c cdns3_plat_resume+0x18/0x24 platform_pm_resume+0x2c/0x68 dpm_run_callback+0x90/0x248 device_resume+0x100/0x24c dpm_resume+0x190/0x2ec dpm_resume_end+0x18/0x34 suspend_devices_and_enter+0x2b0/0xa44 pm_suspend+0x16c/0x5fc state_store+0x80/0xec kobj_attr_store+0x18/0x2c sysfs_kf_write+0x7c/0x94 kernfs_fop_write_iter+0x130/0x1dc vfs_write+0x240/0x370 ksys_write+0x70/0x108 __arm64_sys_write+0x1c/0x28 invoke_syscall+0x48/0x10c el0_svc_common.constprop.0+0x40/0xe0 do_el0_svc+0x1c/0x28 el0_svc+0x34/0x108 el0t_64_sync_handler+0xa0/0xe4 el0t_64_sync+0x198/0x19c Code: 52800003 f9407ca5 d63f00a0 17ffffe4 (f9410401) ---[ end trace 0000000000000000 ]---

Quoted source text, attributed separately from HOL analysis.

In the Linux kernel, the following vulnerability has been resolved: usb: cdns3: fix role switching during resume If the role change while we are suspended, the cdns3 driver switches to the new mode during resume. However, switching to host mode in this context causes a NULL pointer dereference. The host role's start() operation registers a xhci-hcd device, but its probe is deferred while we are in the resume path. The host role's resume() operation assumes the xhci-hcd device is already probed, which is not the case, leading to the dereference. Since the start() operation of the new role is already called, the resume operation can be skipped. So skip the resume operation for the new role if a role switch occurs during resume. Once the resume sequence is complete, the xhci-hcd device can be probed in case of host mode. Unable to handle kernel NULL pointer dereference at virtual address 0000000000000208 Mem abort info: ... Data abort info: ... [0000000000000208] pgd=0000000000000000, p4d=0000000000000000 Internal error: Oops: 0000000096000004 [#1] SMP Modules linked in: CPU: 0 UID: 0 PID: 146 Comm: sh Not tainted 6.19.0-rc7-00013-g6e64f4aabfae-dirty #135 PREEMPT Hardware name: Texas Instruments J7200 EVM (DT) pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : usb_hcd_is_primary_hcd+0x0/0x1c lr : cdns_host_resume+0x24/0x5c ... Call trace: usb_hcd_is_primary_hcd+0x0/0x1c (P) cdns_resume+0x6c/0xbc cdns3_controller_resume.isra.0+0xe8/0x17c cdns3_plat_resume+0x18/0x24 platform_pm_resume+0x2c/0x68 dpm_run_callback+0x90/0x248 device_resume+0x100/0x24c dpm_resume+0x190/0x2ec dpm_resume_end+0x18/0x34 suspend_devices_and_enter+0x2b0/0xa44 pm_suspend+0x16c/0x5fc state_store+0x80/0xec kobj_attr_store+0x18/0x2c sysfs_kf_write+0x7c/0x94 kernfs_fop_write_iter+0x130/0x1dc vfs_write+0x240/0x370 ksys_write+0x70/0x108 __arm64_sys_write+0x1c/0x28 invoke_syscall+0x48/0x10c el0_svc_common.constprop.0+0x40/0xe0 do_el0_svc+0x1c/0x28 el0_svc+0x34/0x108 el0t_64_sync_handler+0xa0/0xe4 el0t_64_sync+0x198/0x19c Code: 52800003 f9407ca5 d63f00a0 17ffffe4 (f9410401) ---[ end trace 0000000000000000 ]---

Quoted source text, attributed separately from HOL analysis.