Commit 61e6ba03 authored May 28, 2020 by Suganath Prabu S Committed by Martin K. Petersen Jun 02, 2020

scsi: mpt3sas: Fix memset() in non-RDPQ mode

Fix memset() accessing out of range address when reply_queue count is less
than RDPQ_MAX_INDEX_IN_ONE_CHUNK (i.e. 16) in non-RDPQ mode.

In non-RDPQ mode, the driver allocates a single contiguous pool of size
reply_queue's count * reqly_post_free_sz. But the driver is always
memsetting this pool with size 16 * reqly_post_free_sz. If reply queue
count is less than 16 (i.e. when MSI-X vectors enabled < 16), the driver is
accessing out of range address and this results in 'BUG: unable to handle
kernel paging request at fff0x...x' bug.

Make driver use dma_pool_zalloc() API to allocate and zero the pool.

Link: https://lore.kernel.org/r/20200528145617.27252-1-suganath-prabu.subramani@broadcom.com

Fixes: 8012209e ("scsi: mpt3sas: Handle RDPQ DMA allocation in same 4G region")
Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

parent 0267ffce

drivers/scsi/mpt3sas/mpt3sas_base.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -4984,7 +4984,7 @@ base_alloc_rdpq_dma_pool(struct MPT3SAS_ADAPTER *ioc, int sz)
		for (i = 0; i < count; i++) {
		if ((i % RDPQ_MAX_INDEX_IN_ONE_CHUNK == 0) && dma_alloc_count) {
		ioc->reply_post[i].reply_post_free =
		dma_pool_alloc(ioc->reply_post_free_dma_pool,
		dma_pool_zalloc(ioc->reply_post_free_dma_pool,
		GFP_KERNEL,
		&ioc->reply_post[i].reply_post_free_dma);
		if (!ioc->reply_post[i].reply_post_free)
		@@ -5008,9 +5008,6 @@ base_alloc_rdpq_dma_pool(struct MPT3SAS_ADAPTER *ioc, int sz)
		ioc->reply_post[i].reply_post_free_dma));
		return -EAGAIN;
		}
		memset(ioc->reply_post[i].reply_post_free, 0,
		RDPQ_MAX_INDEX_IN_ONE_CHUNK *
		reply_post_free_sz);
		dma_alloc_count--;

		} else {

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