CVE-2022-49826

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.