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: BUG: kernel NULL pointer dereference, address: 000000000000041c Call Trace: <TASK> mpi3mr_bsg_exit+0x1f/0x50 [mpi3mr] mpi3mr_remove+0x6f/0x340 [mpi3mr] pci_device_remove+0x3f/0xb0 device_release_driver_internal+0x19d/0x220 unbind_store+0xa4/0xb0 kernfs_fop_write_iter+0x11f/0x200 vfs_write+0x1fc/0x3e0 ksys_write+0x67/0xe0 do_syscall_64+0x38/0x80 entry_SYSCALL_64_after_hwframe+0x78/0xe2 Fixes: 4268fa751365 ("scsi: mpi3mr: Add bsg device support") Signed-off-by: Guixin Liu <kanie@xxxxxxxxxxxxxxxxx> Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx> --- Changes from v3 to v4: - Clean up the call trace (Bart). - Add the rb tag from Bart, thanks. 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; } /** -- 2.43.0