CVE-2022-49826 ata: libata-transport: fix double ata_host_put() in ata_tport_add()
A double free error in the Linux kernel's libata transport layer leads to a null pointer dereference, causing a system crash during device unbinding.
- 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-2022-49826?
CVE-2022-49826 is a high-severity vulnerability in Linux kernel, published on 1 May 2025. 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:
ata: libata-transport: fix double ata_host_put() in ata_tport_add()
In the error path in ata_tport_add(), when calling put_device(), ata_tport_release() is called, it will put the refcount of 'ap->host'.
And then ata_host_put() is called again, the refcount is decreased to 0, ata_host_release() is called, all ports are freed and set to null.
When unbinding the device after failure, ata_host_stop() is called to release the resources, it leads a null-ptr-deref(), because all the ports all freed and null.
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 CPU: 7 PID: 18671 Comm: modprobe Kdump: loaded Tainted: G E 6.1.0-rc3+ #8 pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : ata_host_stop+0x3c/0x84 [libata] lr : release_nodes+0x64/0xd0 Call trace: ata_host_stop+0x3c/0x84 [libata] release_nodes+0x64/0xd0 devres_release_all+0xbc/0x1b0 device_unbind_cleanup+0x20/0x70 really_probe+0x158/0x320 __driver_probe_device+0x84/0x120 driver_probe_device+0x44/0x120 __driver_attach+0xb4/0x220 bus_for_each_dev+0x78/0xdc driver_attach+0x2c/0x40 bus_add_driver+0x184/0x240 driver_register+0x80/0x13c __pci_register_driver+0x4c/0x60 ahci_pci_driver_init+0x30/0x1000 [ahci]
Fix this by removing redundant ata_host_put() in the error path.
Weakness: CWE-415
Which versions are affected by CVE-2022-49826?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49826?
Apply the vendor's patch.
Is CVE-2022-49826 being exploited?
There is no known exploitation of CVE-2022-49826 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49826, GHSA-56f2-3g4j-6qjh, UBUNTU-CVE-2022-49826.