CVE-2021-47283 net:sfc: fix non-freed irq in legacy irq mode
A resource leak in the SFC network driver when using legacy IRQ mode can lead to memory exhaustion and denial of service upon 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-2021-47283?
CVE-2021-47283 is a medium-severity denial of service vulnerability in Linux kernel, published on 21 May 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:
net:sfc: fix non-freed irq in legacy irq mode
SFC driver can be configured via modparam to work using MSI-X, MSI or legacy IRQ interrupts. In the last one, the interrupt was not properly released on module remove.
It was not freed because the flag irqs_hooked was not set during initialization in the case of using legacy IRQ.
Example of (trimmed) trace during module remove without this fix:
remove_proc_entry: removing non-empty directory 'irq/125', leaking at least '0000:3b:00.1' WARNING: CPU: 39 PID: 3658 at fs/proc/generic.c:715 remove_proc_entry+0x15c/0x170 ...trimmed... Call Trace: unregister_irq_proc+0xe3/0x100 free_desc+0x29/0x70 irq_free_descs+0x47/0x70 mp_unmap_irq+0x58/0x60 acpi_unregister_gsi_ioapic+0x2a/0x40 acpi_pci_irq_disable+0x78/0xb0 pci_disable_device+0xd1/0x100 efx_pci_remove+0xa1/0x1e0 [sfc] pci_device_remove+0x38/0xa0 __device_release_driver+0x177/0x230 driver_detach+0xcb/0x110 bus_remove_driver+0x58/0xd0 pci_unregister_driver+0x2a/0xb0 efx_exit_module+0x24/0xf40 [sfc] __do_sys_delete_module.constprop.0+0x171/0x280 ? exit_to_user_mode_prepare+0x83/0x1d0 do_syscall_64+0x3d/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f9f9385800b ...trimmed...
Weakness: CWE-772
Which versions are affected by CVE-2021-47283?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2021-47283?
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-2021-47283 being exploited?
There is no known exploitation of CVE-2021-47283 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2021-47283, GHSA-2277-9x7j-58f3, UBUNTU-CVE-2021-47283.