Re: [PATCH] scsi: target: tcm_loop: fix segfault in tcm_loop_tpg_address_show()

[Martin K. Petersen]

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

-- 
Martin K. Petersen