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authorscameron@beardog.cce.hp.com <scameron@beardog.cce.hp.com>2014-04-14 14:01:09 -0500
committerJames Bottomley <JBottomley@Parallels.com>2014-04-21 07:56:53 -0700
commit67c99a72e3006e4276e91d7282a3d6734fc77a0b (patch)
tree09ae42238805bdbc9f7f555187c40cfccb561685 /drivers/scsi/hpsa.c
parentc9eaa447e77efe77b7fa4c953bd62de8297fd6c5 (diff)
[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 <scameron@beardog.cce.hp.com> Reported-by: Baoquan He <bhe@redhat.com> Tested-by: Baoquan He <bhe@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/hpsa.c')
-rw-r--r--drivers/scsi/hpsa.c8
1 files changed, 4 insertions, 4 deletions
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 */