Linux Kernel Vulnerability Fix: Null-Ptr Deref in Target_Alloc_Device()

CVE-2024-50153

Summary

In the Linux kernel, the following vulnerability has been resolved:

scsi: target: core: Fix null-ptr-deref in target_alloc_device()

There is a null-ptr-deref issue reported by KASAN:

BUG: KASAN: null-ptr-deref in target_alloc_device+0xbc4/0xbe0 [target_core_mod] ... kasan_report+0xb9/0xf0 target_alloc_device+0xbc4/0xbe0 [target_core_mod] core_dev_setup_virtual_lun0+0xef/0x1f0 [target_core_mod] target_core_init_configfs+0x205/0x420 [target_core_mod] do_one_initcall+0xdd/0x4e0 ... entry_SYSCALL_64_after_hwframe+0x76/0x7e

In target_alloc_device(), if allocing memory for dev queues fails, then dev will be freed by dev->transport->free_device(), but dev->transport is not initialized at that time, which will lead to a null pointer reference problem.

Fixing this bug by freeing dev with hba->backend->ops->free_device().

References