Re: [PATCH v3] scsi: mpi3mr: fix possible crash when setup bsg fail

[Guixin Liu <kanie@linux.alibaba.com>]

Friendly ping...

BR,

Guixin Liu

在 2024/12/26 20:18, Guixin Liu 写道:
> If bsg_setup_queue() fails, the bsg_queue is assigned a non-NULL value.
> Consequently, in mpi3mr_bsg_exit(), the condition
> "if(!mrioc->bsg_queue)" will not be satisfied, preventing execution
> from entering bsg_remove_queue(), which could lead to the following
> crash:
>
> [   85.349992] BUG: kernel NULL pointer dereference, address:
> 000000000000041c
> [   85.349998] #PF: supervisor read access in kernel mode
> [   85.350000] #PF: error_code(0x0000) - not-present page
> [   85.350002] PGD 0 P4D 0
> [   85.350004] Oops: 0000 [#1] PREEMPT SMP NOPTI
> [   85.350006] CPU: 2 PID: 4675 Comm: bash Kdump: loaded Tainted: G
> E      6.6.63-cbp.git.f6b4ae219.an23.x86_64 #1
> [   85.350009] Hardware name: IEIT SYSTEMS
> NF5280-M7-A0-R0-00/NF5280-M7-A0-R0-00, BIOS 06.04.01 07/22/2024
> [   85.350010] RIP: 0010:bsg_remove_queue+0x10/0x50
> [   85.350019] Code: 01 00 00 e9 92 92 fe ff 66 90 90 90 90 90 90 90 90
> 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 48 85 ff 74 3a 55
> 53 <48> 8b af 28 04 00 00 48 89 fb 48 8b bd c8 00 00 00 e8 1a f9 ff ff
> [   85.350021] RSP: 0018:ffffc9000f637d40 EFLAGS: 00010282
> [   85.350022] RAX: 0000000000000001 RBX: ffff88810a20aa50 RCX:
> 0000000000000000
> [   85.350023] RDX: 0000000000000000 RSI: 0000000000000293 RDI:
> fffffffffffffff4
> [   85.350024] RBP: ffff88810a20ad58 R08: 0000000000000004 R09:
> ffffc9000f637cfc
> [   85.350025] R10: 0000000000000037 R11: ffffffffa8d22d60 R12:
> ffff88810a20aa50
> [   85.350026] R13: ffff888110e52160 R14: ffff888110e57160 R15:
> ffff8882123399a0
> [   85.350027] FS:  00007f6f2d673740(0000) GS:ffff88903e100000(0000)
> knlGS:0000000000000000
> [   85.350028] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   85.350029] CR2: 000000000000041c CR3: 000000112dec6003 CR4:
> 0000000000f70ee0
> [   85.350030] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
> 0000000000000000
> [   85.350031] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7:
> 0000000000000400
> [   85.350032] PKRU: 55555554
> [   85.350033] Call Trace:
> [   85.350035]  <TASK>
> [   85.350037]  ? __die+0x23/0x70
> [   85.350043]  ? page_fault_oops+0x75/0x170
> [   85.350046]  ? notify_change+0x44e/0x4f0
> [   85.350052]  ? exc_page_fault+0x67/0x140
> [   85.350059]  ? asm_exc_page_fault+0x26/0x30
> [   85.350065]  ? __pfx_pci_conf1_read+0x10/0x10
> [   85.350071]  ? bsg_remove_queue+0x10/0x50
> [   85.350077]  mpi3mr_bsg_exit+0x1f/0x50 [mpi3mr]
> [   85.350090]  mpi3mr_remove+0x6f/0x340 [mpi3mr]
> [   85.350097]  pci_device_remove+0x3f/0xb0
> [   85.350104]  device_release_driver_internal+0x19d/0x220
> [   85.350110]  unbind_store+0xa4/0xb0
> [   85.350114]  kernfs_fop_write_iter+0x11f/0x200
> [   85.350119]  vfs_write+0x1fc/0x3e0
> [   85.350126]  ksys_write+0x67/0xe0
> [   85.350128]  do_syscall_64+0x38/0x80
> [   85.350133]  entry_SYSCALL_64_after_hwframe+0x78/0xe2
> [   85.350136] RIP: 0033:0x7f6f2c32e4e8
> [   85.350138] Code: 89 02 48 c7 c0 ff ff ff ff eb b3 0f 1f 80 00 00 00
> 00 f3 0f 1e fa 48 8d 05 75 72 2a 00 8b 00 85 c0 75 17 b8 01 00 00 00 0f
> 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 41 54 49 89 d4 55
> [   85.350139] RSP: 002b:00007fff133ad218 EFLAGS: 00000246 ORIG_RAX:
> 0000000000000001
> [   85.350140] RAX: ffffffffffffffda RBX: 000000000000000d RCX:
> 00007f6f2c32e4e8
> [   85.350141] RDX: 000000000000000d RSI: 0000557e657fca70 RDI:
> 0000000000000001
> [   85.350142] RBP: 0000557e657fca70 R08: 000000000000000a R09:
> 00007f6f2c390160
> [   85.350142] R10: 000000000000000a R11: 0000000000000246 R12:
> 00007f6f2c5d16e0
> [   85.350143] R13: 000000000000000d R14: 00007f6f2c5cc860 R15:
> 000000000000000d
> [   85.350144]  </TASK>
>
> Fixes: 4268fa751365 ("scsi: mpi3mr: Add bsg device support")
> Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
> ---
> Changes from v2 to v3:
> - Add the crash stack to commit body.
>
> Changes from v1 to v2:
> - Add return statement when setup bsg queue fail, sorry for the v1
> trouble.
>   drivers/scsi/mpi3mr/mpi3mr_app.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/mpi3mr/mpi3mr_app.c b/drivers/scsi/mpi3mr/mpi3mr_app.c
> index 10b8e4dc64f8..7589f48aebc8 100644
> --- a/drivers/scsi/mpi3mr/mpi3mr_app.c
> +++ b/drivers/scsi/mpi3mr/mpi3mr_app.c
> @@ -2951,6 +2951,7 @@ void mpi3mr_bsg_init(struct mpi3mr_ioc *mrioc)
>   		.max_hw_sectors		= MPI3MR_MAX_APP_XFER_SECTORS,
>   		.max_segments		= MPI3MR_MAX_APP_XFER_SEGMENTS,
>   	};
> +	struct request_queue *q;
>   
>   	device_initialize(bsg_dev);
>   
> @@ -2966,14 +2967,17 @@ void mpi3mr_bsg_init(struct mpi3mr_ioc *mrioc)
>   		return;
>   	}
>   
> -	mrioc->bsg_queue = bsg_setup_queue(bsg_dev, dev_name(bsg_dev), &lim,
> +	q = bsg_setup_queue(bsg_dev, dev_name(bsg_dev), &lim,
>   			mpi3mr_bsg_request, NULL, 0);
> -	if (IS_ERR(mrioc->bsg_queue)) {
> +	if (IS_ERR(q)) {
>   		ioc_err(mrioc, "%s: bsg registration failed\n",
>   		    dev_name(bsg_dev));
>   		device_del(bsg_dev);
>   		put_device(bsg_dev);
> +		return;
>   	}
> +
> +	mrioc->bsg_queue = q;
>   }
>   
>   /**