On Wed, 05 Nov 2025 11:25:46 -0800, Hamza Mahfooz wrote:
If the allocation of tl_hba->sh fails in tcm_loop_driver_probe() and we attempt to dereference it in tcm_loop_tpg_address_show() we will get a segfault, see below for an example. So, check tl_hba->sh before dereferencing it.
Unable to allocate struct scsi_host BUG: kernel NULL pointer dereference, address: 0000000000000194 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 8356 Comm: tokio-runtime-w Not tainted 6.6.104.2-4.azl3 #1 Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 09/28/2024 RIP: 0010:tcm_loop_tpg_address_show+0x2e/0x50 [tcm_loop] ... Call Trace:
<TASK> configfs_read_iter+0x12d/0x1d0 [configfs] vfs_read+0x1b5/0x300 ksys_read+0x6f/0xf0 ...
[...]
Applied to 6.18/scsi-fixes, thanks!
[1/1] scsi: target: tcm_loop: fix segfault in tcm_loop_tpg_address_show() https://git.kernel.org/mkp/scsi/c/e6965188f84a