CVE-2026-23032

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

null_blk: fix kmemleak by releasing references to fault configfs items

When CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION is enabled, the null-blk driver sets up fault injection support by creating the timeout_inject, requeue_inject, and init_hctx_fault_inject configfs items as children of the top-level nullbX configfs group.

However, when the nullbX device is removed, the references taken to these fault-config configfs items are not released. As a result, kmemleak reports a memory leak, for example:

unreferenced object 0xc00000021ff25c40 (size 32): comm "mkdir", pid 10665, jiffies 4322121578 hex dump (first 32 bytes): 69 6e 69 74 5f 68 63 74 78 5f 66 61 75 6c 74 5f init_hctx_fault_ 69 6e 6a 65 63 74 00 88 00 00 00 00 00 00 00 00 inject.......... backtrace (crc 1a018c86): __kmalloc_node_track_caller_noprof+0x494/0xbd8 kvasprintf+0x74/0xf4 config_item_set_name+0xf0/0x104 config_group_init_type_name+0x48/0xfc fault_config_init+0x48/0xf0 0xc0080000180559e4 configfs_mkdir+0x304/0x814 vfs_mkdir+0x49c/0x604 do_mkdirat+0x314/0x3d0 sys_mkdir+0xa0/0xd8 system_call_exception+0x1b0/0x4f0 system_call_vectored_common+0x15c/0x2ec

Fix this by explicitly releasing the references to the fault-config configfs items when dropping the reference to the top-level nullbX configfs group.

null_blk fault injection configfs items were not released on device removal, causing a memory leak that can accumulate over repeated create and delete cycles. PR:H is typically required to manage configfs and null_blk devices, and the issue is not network reachable. Impact is denial of service via resource exhaustion.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.