CVE-2021-47503 Information

Description

In the Linux kernel the following vulnerability has been resolved:

scsi: pm80xx: Do not call scsi_remove_host() in pm8001_alloc()

Calling scsi_remove_host() before scsi_add_host() results in a crash:

BUG: kernel NULL pointer dereference address: 0000000000000108 RIP: 0010:device_del+0x63/0x440 Call Trace: device_unregister+0x17/0x60 scsi_remove_host+0xee/0x2a0 pm8001_pci_probe+0x6ef/0x1b90 [pm80xx] local_pci_probe+0x3f/0x90

We cannot call scsi_remove_host() in pm8001_alloc() because scsi_add_host() has not been called yet at that point in time.

Function call tree:

pm8001_pci_probe() | - pm8001_pci_alloc() | | | - pm8001_alloc() | | | - scsi_remove_host() | - scsi_add_host()

Reference

https://git.kernel.org/stable/c/1e434d2687e8bc0b3cdc9dd093c0e9047c0b4add https://git.kernel.org/stable/c/f8dccc1bdea7e21b5ec06c957aef8831c772661c https://git.kernel.org/stable/c/653926205741add87a6cf452e21950eebc6ac10b