CVE-2026-93098 rpmsg: glink: fix deadlock in endpoint destroy during driver detach
A local attacker can cause a system hang by triggering a deadlock in the Linux kernel's GLINK driver during module removal.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-93098?
CVE-2026-93098 is a denial of service vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
rpmsg: glink: fix deadlock in endpoint destroy during driver detach
During driver detach, the device core holds the device mutex throughout the driver's remove callback chain. When the rpmsg endpoint is destroyed as part of that teardown, the GLINK endpoint destroy implementation attempts to unregister the underlying rpmsg device. That unregistration calls device_del(), which tries to re-acquire the same device mutex already held higher up the stack, causing rmmod to hang indefinitely.
The deadlock manifests with the following call chain:
[<0>] device_del+0x44/0x414 <- tries to acquire same mutex [<0>] device_unregister+0x18/0x34 [<0>] rpmsg_unregister_device+0x28/0x4c [<0>] qcom_glink_remove_rpmsg_device+0x70/0xc0 [<0>] qcom_glink_destroy_ept+0x58/0xbc [<0>] rpmsg_dev_remove+0x50/0x60 [<0>] device_remove+0x4c/0x80 [<0>] device_release_driver_internal+0x1cc/0x228 <- acquires device mutex [<0>] driver_detach+0x4c/0x98 [<0>] bus_remove_driver+0x6c/0xbc [<0>] driver_unregister+0x30/0x60 [<0>] unregister_rpmsg_driver+0x10/0x1c [<0>] fastrpc_exit+0x28/0x38 [fastrpc] [<0>] __arm64_sys_delete_module+0x1b8/0x294 [<0>] invoke_syscall+0x48/0x10c [<0>] el0_svc_common.constprop.0+0xc0/0xe0 [<0>] do_el0_svc+0x1c/0x28 [<0>] el0_svc+0x34/0x108 [<0>] el0t_64_sync_handler+0xa0/0xe4 [<0>] el0t_64_sync+0x198/0x19c
The rpmsg device unregistration inside endpoint destroy is redundant. In both contexts where endpoint destruction is triggered:
- Driver detach path: the driver core already tears down the rpmsg device.
- Channel close path: the rpmsg device is already unregistered before endpoint destruction is reached.
Remove the redundant unregistration to fix the deadlock.
Which versions are affected by CVE-2026-93098?
How do I fix CVE-2026-93098?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-93098 being exploited?
There is no known exploitation of CVE-2026-93098 in the wild and no public exploit code.
Sources
Also known as AZL-101891, BELL-CVE-2026-93098, DEBIAN-CVE-2026-93098, GHSA-rmpv-cfqv-cmjx, UBUNTU-CVE-2026-93098.