From 67c99a72e3006e4276e91d7282a3d6734fc77a0b Mon Sep 17 00:00:00 2001 From: "scameron@beardog.cce.hp.com" Date: Mon, 14 Apr 2014 14:01:09 -0500 Subject: [SCSI] hpsa: fix NULL dereference in hpsa_put_ctlr_into_performant_mode() Initialize local variable trans_support before it is used rather than after. It is supposed to contain the value of a register on the controller containing bits that describe which transport modes the controller supports (e.g. "performant", "ioaccel1", "ioaccel2"). A NULL pointer dereference will almost certainly occur if trans_support is not initialized at the right point. If for example the uninitialized trans_support value does not have the bit set for ioaccel2 support when it should be, then ioaccel2_alloc_cmds_and_bft() will not get called as it should be and the h->ioaccel2_blockFetchTable array will remain NULL instead of being allocated. Too late, trans_support finally gets initialized with the correct value with ioaccel2 mode bit set, which later causes calc_bucket_map() to be called to fill in h->ioaccel2_blockFetchTable[]. However h->ioaccel2_blockFetchTable is NULL because it didn't get allocated because earlier trans_support wasn't initialized at the right point. Fixes: e1f7de0cdd68d246d7008241cd9e443a54f880a8 Signed-off-by: Stephen M. Cameron Reported-by: Baoquan He Tested-by: Baoquan He Signed-off-by: James Bottomley --- drivers/scsi/hpsa.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/scsi/hpsa.c') diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index 8cf4a0c69baf..9a6e4a2cd072 100644 --- a/drivers/scsi/hpsa.c +++ b/drivers/scsi/hpsa.c @@ -7463,6 +7463,10 @@ static void hpsa_put_ctlr_into_performant_mode(struct ctlr_info *h) if (hpsa_simple_mode) return; + trans_support = readl(&(h->cfgtable->TransportSupport)); + if (!(trans_support & PERFORMANT_MODE)) + return; + /* Check for I/O accelerator mode support */ if (trans_support & CFGTBL_Trans_io_accel1) { transMethod |= CFGTBL_Trans_io_accel1 | @@ -7479,10 +7483,6 @@ static void hpsa_put_ctlr_into_performant_mode(struct ctlr_info *h) } /* TODO, check that this next line h->nreply_queues is correct */ - trans_support = readl(&(h->cfgtable->TransportSupport)); - if (!(trans_support & PERFORMANT_MODE)) - return; - h->nreply_queues = h->msix_vector > 0 ? h->msix_vector : 1; hpsa_get_max_perf_mode_cmds(h); /* Performant mode ring buffer and supporting data structures */ -- cgit v1.2.3