CVE-2021-47005 PCI: endpoint: Fix NULL pointer dereference for ->get_features()
A local attacker can cause a kernel crash by triggering a NULL pointer dereference in the PCI endpoint test driver when specific features are unimplemented.
- 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-2021-47005?
CVE-2021-47005 is a medium-severity vulnerability in Linux kernel, published on 28 Feb 2024. 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:
PCI: endpoint: Fix NULL pointer dereference for ->get_features()
get_features ops of pci_epc_ops may return NULL, causing NULL pointer dereference in pci_epf_test_alloc_space function. Let us add a check for pci_epc_feature pointer in pci_epf_test_bind before we access it to avoid any such NULL pointer dereference and return -ENOTSUPP in case pci_epc_feature is not found.
When the patch is not applied and EPC features is not implemented in the platform driver, we see the following dump due to kernel NULL pointer dereference.
Call trace: pci_epf_test_bind+0xf4/0x388 pci_epf_bind+0x3c/0x80 pci_epc_epf_link+0xa8/0xcc configfs_symlink+0x1a4/0x48c vfs_symlink+0x104/0x184 do_symlinkat+0x80/0xd4 __arm64_sys_symlinkat+0x1c/0x24 el0_svc_common.constprop.3+0xb8/0x170 el0_svc_handler+0x70/0x88 el0_svc+0x8/0x640 Code: d2800581 b9403ab9 f9404ebb 8b394f60 (f9400400) ---[ end trace a438e3c5a24f9df0 ]---
Weakness: CWE-476
Which versions are affected by CVE-2021-47005?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2021-47005?
Apply the vendor's patch.
Is CVE-2021-47005 being exploited?
There is no known exploitation of CVE-2021-47005 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2021-47005, GHSA-43jg-wxfj-4rf7, UBUNTU-CVE-2021-47005.