scsi: mpi3mr: Use number of bits to manage bitmap sizes

To allocate bitmaps, the mpi3mr driver calculates sizes of bitmaps using
byte as unit. However, bitmap helper functions assume that bitmaps are
allocated using unsigned long as unit. This gap causes memory access beyond
the bitmap sizes and results in "BUG: KASAN: slab-out-of-bounds".  The BUG
was observed at firmware download to eHBA-9600. Call trace indicated that
the out-of-bounds access happened in find_first_zero_bit() called from
mpi3mr_send_event_ack() for miroc->evtack_cmds_bitmap.

To fix the BUG, do not use bytes to manage bitmap sizes. Instead, use
number of bits, and call bitmap helper functions which take number of bits
as arguments. For memory allocation, call bitmap_zalloc() instead of
kzalloc() and krealloc(). For memory free, call bitmap_free() instead of
kfree(). For zero clear, call bitmap_clear() instead of memset().

Remove three fields for bitmap byte sizes in struct scmd_priv which are no
longer required. Replace the field dev_handle_bitmap_sz with
dev_handle_bitmap_bits to keep number of bits of removepend_bitmap across
resize.

Link: https://lore.kernel.org/r/20230214005019.1897251-4-shinichiro.kawasaki@wdc.com
Fixes: c5758fc7 ("scsi: mpi3mr: Gracefully handle online FW update operation")
Fixes: e844adb1 ("scsi: mpi3mr: Implement SCSI error handler hooks")
Fixes: c1af985d ("scsi: mpi3mr: Add Event acknowledgment logic")
Fixes: 824a1566 ("scsi: mpi3mr: Base driver code")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Acked-by: Sathya Prakash Veerichetty <sathya.prakash@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mpi3mr/mpi3mr.h

@@ -955,19 +955,16 @@ struct scmd_priv {
  * @chain_buf_count: Chain buffer count
  * @chain_buf_pool: Chain buffer pool
  * @chain_sgl_list: Chain SGL list
- * @chain_bitmap_sz: Chain buffer allocator bitmap size
  * @chain_bitmap: Chain buffer allocator bitmap
  * @chain_buf_lock: Chain buffer list lock
  * @bsg_cmds: Command tracker for BSG command
  * @host_tm_cmds: Command tracker for task management commands
  * @dev_rmhs_cmds: Command tracker for device removal commands
  * @evtack_cmds: Command tracker for event ack commands
- * @devrem_bitmap_sz: Device removal bitmap size
  * @devrem_bitmap: Device removal bitmap
- * @dev_handle_bitmap_sz: Device handle bitmap size
+ * @dev_handle_bitmap_bits: Number of bits in device handle bitmap
  * @removepend_bitmap: Remove pending bitmap
  * @delayed_rmhs_list: Delayed device removal list
- * @evtack_cmds_bitmap_sz: Event Ack bitmap size
  * @evtack_cmds_bitmap: Event Ack bitmap
  * @delayed_evtack_cmds_list: Delayed event acknowledgment list
  * @ts_update_counter: Timestamp update counter
@@ -1128,7 +1125,6 @@ struct mpi3mr_ioc {
 	u32 chain_buf_count;
 	struct dma_pool *chain_buf_pool;
 	struct chain_element *chain_sgl_list;
-	u16  chain_bitmap_sz;
 	void *chain_bitmap;
 	spinlock_t chain_buf_lock;
 
@@ -1136,12 +1132,10 @@ struct mpi3mr_ioc {
 	struct mpi3mr_drv_cmd host_tm_cmds;
 	struct mpi3mr_drv_cmd dev_rmhs_cmds[MPI3MR_NUM_DEVRMCMD];
 	struct mpi3mr_drv_cmd evtack_cmds[MPI3MR_NUM_EVTACKCMD];
-	u16 devrem_bitmap_sz;
 	void *devrem_bitmap;
-	u16 dev_handle_bitmap_sz;
+	u16 dev_handle_bitmap_bits;
 	void *removepend_bitmap;
 	struct list_head delayed_rmhs_list;
-	u16 evtack_cmds_bitmap_sz;
 	void *evtack_cmds_bitmap;
 	struct list_head delayed_evtack_cmds_list;
 

drivers/scsi/mpi3mr/mpi3mr_fw.c

@@ -1128,7 +1128,6 @@ static int mpi3mr_issue_and_process_mur(struct mpi3mr_ioc *mrioc,
 static int
 mpi3mr_revalidate_factsdata(struct mpi3mr_ioc *mrioc)
 {
-	u16 dev_handle_bitmap_sz;
 	void *removepend_bitmap;
 
 	if (mrioc->facts.reply_sz > mrioc->reply_sz) {
@@ -1160,25 +1159,23 @@ mpi3mr_revalidate_factsdata(struct mpi3mr_ioc *mrioc)
 		    "\tcontroller while sas transport support is enabled at the\n"
 		    "\tdriver, please reboot the system or reload the driver\n");
 
-	dev_handle_bitmap_sz = mrioc->facts.max_devhandle / 8;
-	if (mrioc->facts.max_devhandle % 8)
-		dev_handle_bitmap_sz++;
-	if (dev_handle_bitmap_sz > mrioc->dev_handle_bitmap_sz) {
-		removepend_bitmap = krealloc(mrioc->removepend_bitmap,
-		    dev_handle_bitmap_sz, GFP_KERNEL);
+	if (mrioc->facts.max_devhandle > mrioc->dev_handle_bitmap_bits) {
+		removepend_bitmap = bitmap_zalloc(mrioc->facts.max_devhandle,
+						  GFP_KERNEL);
 		if (!removepend_bitmap) {
 			ioc_err(mrioc,
-			    "failed to increase removepend_bitmap sz from: %d to %d\n",
-			    mrioc->dev_handle_bitmap_sz, dev_handle_bitmap_sz);
+				"failed to increase removepend_bitmap bits from %d to %d\n",
+				mrioc->dev_handle_bitmap_bits,
+				mrioc->facts.max_devhandle);
 			return -EPERM;
 		}
-		memset(removepend_bitmap + mrioc->dev_handle_bitmap_sz, 0,
-		    dev_handle_bitmap_sz - mrioc->dev_handle_bitmap_sz);
+		bitmap_free(mrioc->removepend_bitmap);
 		mrioc->removepend_bitmap = removepend_bitmap;
 		ioc_info(mrioc,
-		    "increased dev_handle_bitmap_sz from %d to %d\n",
-		    mrioc->dev_handle_bitmap_sz, dev_handle_bitmap_sz);
-		mrioc->dev_handle_bitmap_sz = dev_handle_bitmap_sz;
+			 "increased bits of dev_handle_bitmap from %d to %d\n",
+			 mrioc->dev_handle_bitmap_bits,
+			 mrioc->facts.max_devhandle);
+		mrioc->dev_handle_bitmap_bits = mrioc->facts.max_devhandle;
 	}
 
 	return 0;
@@ -2957,27 +2954,18 @@ static int mpi3mr_alloc_reply_sense_bufs(struct mpi3mr_ioc *mrioc)
 	if (!mrioc->pel_abort_cmd.reply)
 		goto out_failed;
 
-	mrioc->dev_handle_bitmap_sz = mrioc->facts.max_devhandle / 8;
-	if (mrioc->facts.max_devhandle % 8)
-		mrioc->dev_handle_bitmap_sz++;
-	mrioc->removepend_bitmap = kzalloc(mrioc->dev_handle_bitmap_sz,
-	    GFP_KERNEL);
+	mrioc->dev_handle_bitmap_bits = mrioc->facts.max_devhandle;
+	mrioc->removepend_bitmap = bitmap_zalloc(mrioc->dev_handle_bitmap_bits,
+						 GFP_KERNEL);
 	if (!mrioc->removepend_bitmap)
 		goto out_failed;
 
-	mrioc->devrem_bitmap_sz = MPI3MR_NUM_DEVRMCMD / 8;
-	if (MPI3MR_NUM_DEVRMCMD % 8)
-		mrioc->devrem_bitmap_sz++;
-	mrioc->devrem_bitmap = kzalloc(mrioc->devrem_bitmap_sz,
-	    GFP_KERNEL);
+	mrioc->devrem_bitmap = bitmap_zalloc(MPI3MR_NUM_DEVRMCMD, GFP_KERNEL);
 	if (!mrioc->devrem_bitmap)
 		goto out_failed;
 
-	mrioc->evtack_cmds_bitmap_sz = MPI3MR_NUM_EVTACKCMD / 8;
-	if (MPI3MR_NUM_EVTACKCMD % 8)
-		mrioc->evtack_cmds_bitmap_sz++;
-	mrioc->evtack_cmds_bitmap = kzalloc(mrioc->evtack_cmds_bitmap_sz,
-	    GFP_KERNEL);
+	mrioc->evtack_cmds_bitmap = bitmap_zalloc(MPI3MR_NUM_EVTACKCMD,
+						  GFP_KERNEL);
 	if (!mrioc->evtack_cmds_bitmap)
 		goto out_failed;
 
@@ -3415,10 +3403,7 @@ static int mpi3mr_alloc_chain_bufs(struct mpi3mr_ioc *mrioc)
 		if (!mrioc->chain_sgl_list[i].addr)
 			goto out_failed;
 	}
-	mrioc->chain_bitmap_sz = num_chains / 8;
-	if (num_chains % 8)
-		mrioc->chain_bitmap_sz++;
-	mrioc->chain_bitmap = kzalloc(mrioc->chain_bitmap_sz, GFP_KERNEL);
+	mrioc->chain_bitmap = bitmap_zalloc(num_chains, GFP_KERNEL);
 	if (!mrioc->chain_bitmap)
 		goto out_failed;
 	return retval;
@@ -4190,10 +4175,11 @@ void mpi3mr_memset_buffers(struct mpi3mr_ioc *mrioc)
 		for (i = 0; i < MPI3MR_NUM_EVTACKCMD; i++)
 			memset(mrioc->evtack_cmds[i].reply, 0,
 			    sizeof(*mrioc->evtack_cmds[i].reply));
-		memset(mrioc->removepend_bitmap, 0, mrioc->dev_handle_bitmap_sz);
-		memset(mrioc->devrem_bitmap, 0, mrioc->devrem_bitmap_sz);
-		memset(mrioc->evtack_cmds_bitmap, 0,
-		    mrioc->evtack_cmds_bitmap_sz);
+		bitmap_clear(mrioc->removepend_bitmap, 0,
+			     mrioc->dev_handle_bitmap_bits);
+		bitmap_clear(mrioc->devrem_bitmap, 0, MPI3MR_NUM_DEVRMCMD);
+		bitmap_clear(mrioc->evtack_cmds_bitmap, 0,
+			     MPI3MR_NUM_EVTACKCMD);
 	}
 
 	for (i = 0; i < mrioc->num_queues; i++) {
@@ -4319,16 +4305,16 @@ void mpi3mr_free_mem(struct mpi3mr_ioc *mrioc)
 		mrioc->evtack_cmds[i].reply = NULL;
 	}
 
-	kfree(mrioc->removepend_bitmap);
+	bitmap_free(mrioc->removepend_bitmap);
 	mrioc->removepend_bitmap = NULL;
 
-	kfree(mrioc->devrem_bitmap);
+	bitmap_free(mrioc->devrem_bitmap);
 	mrioc->devrem_bitmap = NULL;
 
-	kfree(mrioc->evtack_cmds_bitmap);
+	bitmap_free(mrioc->evtack_cmds_bitmap);
 	mrioc->evtack_cmds_bitmap = NULL;
 
-	kfree(mrioc->chain_bitmap);
+	bitmap_free(mrioc->chain_bitmap);
 	mrioc->chain_bitmap = NULL;
 
 	kfree(mrioc->transport_cmds.reply);
@@ -4887,9 +4873,10 @@ int mpi3mr_soft_reset_handler(struct mpi3mr_ioc *mrioc,
 
 	mpi3mr_flush_delayed_cmd_lists(mrioc);
 	mpi3mr_flush_drv_cmds(mrioc);
-	memset(mrioc->devrem_bitmap, 0, mrioc->devrem_bitmap_sz);
-	memset(mrioc->removepend_bitmap, 0, mrioc->dev_handle_bitmap_sz);
-	memset(mrioc->evtack_cmds_bitmap, 0, mrioc->evtack_cmds_bitmap_sz);
+	bitmap_clear(mrioc->devrem_bitmap, 0, MPI3MR_NUM_DEVRMCMD);
+	bitmap_clear(mrioc->removepend_bitmap, 0,
+		     mrioc->dev_handle_bitmap_bits);
+	bitmap_clear(mrioc->evtack_cmds_bitmap, 0, MPI3MR_NUM_EVTACKCMD);
 	mpi3mr_flush_host_io(mrioc);
 	mpi3mr_cleanup_fwevt_list(mrioc);
 	mpi3mr_invalidate_devhandles(mrioc);