CVE-2023-53282

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

scsi: lpfc: Fix use-after-free KFENCE violation during sysfs firmware write

During the sysfs firmware write process, a use-after-free read warning is logged from the lpfc_wr_object() routine:

BUG: KFENCE: use-after-free read in lpfc_wr_object+0x235/0x310 [lpfc] Use-after-free read at 0x0000000000cf164d (in kfence-#111): lpfc_wr_object+0x235/0x310 [lpfc] lpfc_write_firmware.cold+0x206/0x30d [lpfc] lpfc_sli4_request_firmware_update+0xa6/0x100 [lpfc] lpfc_request_firmware_upgrade_store+0x66/0xb0 [lpfc] kernfs_fop_write_iter+0x121/0x1b0 new_sync_write+0x11c/0x1b0 vfs_write+0x1ef/0x280 ksys_write+0x5f/0xe0 do_syscall_64+0x59/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The driver accessed wr_object pointer data, which was initialized into mailbox payload memory, after the mailbox object was released back to the mailbox pool.

Fix by moving the mailbox free calls to the end of the routine ensuring that we don't reference internal mailbox memory after release.

A use-after-free was found in the lpfc firmware sysfs write path: the driver freed a buffer and then continued to read fields from it, triggering UAF reads and potential kernel crashes. This path is admin-only (firmware update via sysfs), and remote exploitation is not feasible under normal deployments.

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.