USB: ene_usb6250: fix DMA to the stack

The ene_usb6250 sub-driver in usb-storage does USB I/O to buffers on
the stack, which doesn't work with vmapped stacks.  This patch fixes
the problem by allocating a separate 512-byte buffer at probe time and
using it for all of the offending I/O operations.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: Andreas Hartmann <andihartmann@01019freenet.de>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 55 insertions, 35 deletions

diff --git a/drivers/usb/storage/ene_ub6250.c b/drivers/usb/storage/ene_ub6250.c
index 369f3c24815a..44af719194b2 100644
--- a/drivers/usb/storage/ene_ub6250.c
+++ b/drivers/usb/storage/ene_ub6250.c
@@ -446,6 +446,10 @@ struct ms_lib_ctrl {
 #define SD_BLOCK_LEN  9
 
 struct ene_ub6250_info {
+
+        /* I/O bounce buffer */
+        u8              *bbuf;
+
         /* for 6250 code */
         struct SD_STATUS        SD_Status;
         struct MS_STATUS        MS_Status;
@@ -493,8 +497,11 @@ static int ene_load_bincode(struct us_data *us, unsigned char flag);
 
 static void ene_ub6250_info_destructor(void *extra)
 {
+        struct ene_ub6250_info *info = (struct ene_ub6250_info *) extra;
+
         if (!extra)
                 return;
+        kfree(info->bbuf);
 }
 
 static int ene_send_scsi_cmd(struct us_data *us, u8 fDir, void *buf, int use_sg)
@@ -860,8 +867,9 @@ static int ms_read_readpage(struct us_data *us, u32 PhyBlockAddr,
                 u8 PageNum, u32 *PageBuf, struct ms_lib_type_extdat *ExtraDat)
 {
         struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
+        struct ene_ub6250_info *info = (struct ene_ub6250_info *) us->extra;
+        u8 *bbuf = info->bbuf;
         int result;
-        u8 ExtBuf[4];
         u32 bn = PhyBlockAddr * 0x20 + PageNum;
 
         result = ene_load_bincode(us, MS_RW_PATTERN);
@@ -901,7 +909,7 @@ static int ms_read_readpage(struct us_data *us, u32 PhyBlockAddr,
         bcb->CDB[2]     = (unsigned char)(PhyBlockAddr>>16);
         bcb->CDB[6]     = 0x01;
 
-        result = ene_send_scsi_cmd(us, FDIR_READ, &ExtBuf, 0);
+        result = ene_send_scsi_cmd(us, FDIR_READ, bbuf, 0);
         if (result != USB_STOR_XFER_GOOD)
                 return USB_STOR_TRANSPORT_ERROR;
 
@@ -910,9 +918,9 @@ static int ms_read_readpage(struct us_data *us, u32 PhyBlockAddr,
         ExtraDat->status0  = 0x10;  /* Not yet,fireware support */
 
         ExtraDat->status1  = 0x00;  /* Not yet,fireware support */
-        ExtraDat->ovrflg   = ExtBuf[0];
-        ExtraDat->mngflg   = ExtBuf[1];
-        ExtraDat->logadr   = memstick_logaddr(ExtBuf[2], ExtBuf[3]);
+        ExtraDat->ovrflg   = bbuf[0];
+        ExtraDat->mngflg   = bbuf[1];
+        ExtraDat->logadr   = memstick_logaddr(bbuf[2], bbuf[3]);
 
         return USB_STOR_TRANSPORT_GOOD;
 }
@@ -1332,8 +1340,9 @@ static int ms_lib_read_extra(struct us_data *us, u32 PhyBlock,
                                 u8 PageNum, struct ms_lib_type_extdat *ExtraDat)
 {
         struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
+        struct ene_ub6250_info *info = (struct ene_ub6250_info *) us->extra;
+        u8 *bbuf = info->bbuf;
         int result;
-        u8 ExtBuf[4];
 
         memset(bcb, 0, sizeof(struct bulk_cb_wrap));
         bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
@@ -1347,7 +1356,7 @@ static int ms_lib_read_extra(struct us_data *us, u32 PhyBlock,
         bcb->CDB[2]     = (unsigned char)(PhyBlock>>16);
         bcb->CDB[6]     = 0x01;
 
-        result = ene_send_scsi_cmd(us, FDIR_READ, &ExtBuf, 0);
+        result = ene_send_scsi_cmd(us, FDIR_READ, bbuf, 0);
         if (result != USB_STOR_XFER_GOOD)
                 return USB_STOR_TRANSPORT_ERROR;
 
@@ -1355,9 +1364,9 @@ static int ms_lib_read_extra(struct us_data *us, u32 PhyBlock,
         ExtraDat->intr     = 0x80;  /* Not yet, waiting for fireware support */
         ExtraDat->status0  = 0x10;  /* Not yet, waiting for fireware support */
         ExtraDat->status1  = 0x00;  /* Not yet, waiting for fireware support */
-        ExtraDat->ovrflg   = ExtBuf[0];
-        ExtraDat->mngflg   = ExtBuf[1];
-        ExtraDat->logadr   = memstick_logaddr(ExtBuf[2], ExtBuf[3]);
+        ExtraDat->ovrflg   = bbuf[0];
+        ExtraDat->mngflg   = bbuf[1];
+        ExtraDat->logadr   = memstick_logaddr(bbuf[2], bbuf[3]);
 
         return USB_STOR_TRANSPORT_GOOD;
 }
@@ -1556,9 +1565,9 @@ static int ms_lib_scan_logicalblocknumber(struct us_data *us, u16 btBlk1st)
         u16 PhyBlock, newblk, i;
         u16 LogStart, LogEnde;
         struct ms_lib_type_extdat extdat;
-        u8 buf[0x200];
         u32 count = 0, index = 0;
         struct ene_ub6250_info *info = (struct ene_ub6250_info *) us->extra;
+        u8 *bbuf = info->bbuf;
 
         for (PhyBlock = 0; PhyBlock < info->MS_Lib.NumberOfPhyBlock;) {
                 ms_lib_phy_to_log_range(PhyBlock, &LogStart, &LogEnde);
@@ -1572,14 +1581,16 @@ static int ms_lib_scan_logicalblocknumber(struct us_data *us, u16 btBlk1st)
                         }
 
                         if (count == PhyBlock) {
-                                ms_lib_read_extrablock(us, PhyBlock, 0, 0x80, &buf);
+                                ms_lib_read_extrablock(us, PhyBlock, 0, 0x80,
+                                                bbuf);
                                 count += 0x80;
                         }
                         index = (PhyBlock % 0x80) * 4;
 
-                        extdat.ovrflg = buf[index];
-                        extdat.mngflg = buf[index+1];
-                        extdat.logadr = memstick_logaddr(buf[index+2], buf[index+3]);
+                        extdat.ovrflg = bbuf[index];
+                        extdat.mngflg = bbuf[index+1];
+                        extdat.logadr = memstick_logaddr(bbuf[index+2],
+                                        bbuf[index+3]);
 
                         if ((extdat.ovrflg & MS_REG_OVR_BKST) != MS_REG_OVR_BKST_OK) {
                                 ms_lib_setacquired_errorblock(us, PhyBlock);
@@ -2062,9 +2073,9 @@ static int ene_ms_init(struct us_data *us)
 {
         struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
         int result;
-        u8 buf[0x200];
         u16 MSP_BlockSize, MSP_UserAreaBlocks;
         struct ene_ub6250_info *info = (struct ene_ub6250_info *) us->extra;
+        u8 *bbuf = info->bbuf;
 
         printk(KERN_INFO "transport --- ENE_MSInit\n");
 
@@ -2083,13 +2094,13 @@ static int ene_ms_init(struct us_data *us)
         bcb->CDB[0]     = 0xF1;
         bcb->CDB[1]     = 0x01;
 
-        result = ene_send_scsi_cmd(us, FDIR_READ, &buf, 0);
+        result = ene_send_scsi_cmd(us, FDIR_READ, bbuf, 0);
         if (result != USB_STOR_XFER_GOOD) {
                 printk(KERN_ERR "Execution MS Init Code Fail !!\n");
                 return USB_STOR_TRANSPORT_ERROR;
         }
         /* the same part to test ENE */
-        info->MS_Status = *(struct MS_STATUS *)&buf[0];
+        info->MS_Status = *(struct MS_STATUS *) bbuf;
 
         if (info->MS_Status.Insert && info->MS_Status.Ready) {
                 printk(KERN_INFO "Insert     = %x\n", info->MS_Status.Insert);
@@ -2098,15 +2109,15 @@ static int ene_ms_init(struct us_data *us)
                 printk(KERN_INFO "IsMSPHG    = %x\n", info->MS_Status.IsMSPHG);
                 printk(KERN_INFO "WtP= %x\n", info->MS_Status.WtP);
                 if (info->MS_Status.IsMSPro) {
-                        MSP_BlockSize      = (buf[6] << 8) | buf[7];
-                        MSP_UserAreaBlocks = (buf[10] << 8) | buf[11];
+                        MSP_BlockSize      = (bbuf[6] << 8) | bbuf[7];
+                        MSP_UserAreaBlocks = (bbuf[10] << 8) | bbuf[11];
                         info->MSP_TotalBlock = MSP_BlockSize * MSP_UserAreaBlocks;
                 } else {
                         ms_card_init(us); /* Card is MS (to ms.c)*/
                 }
                 usb_stor_dbg(us, "MS Init Code OK !!\n");
         } else {
-                usb_stor_dbg(us, "MS Card Not Ready --- %x\n", buf[0]);
+                usb_stor_dbg(us, "MS Card Not Ready --- %x\n", bbuf[0]);
                 return USB_STOR_TRANSPORT_ERROR;
         }
 
@@ -2116,9 +2127,9 @@ static int ene_ms_init(struct us_data *us)
 static int ene_sd_init(struct us_data *us)
 {
         int result;
-        u8  buf[0x200];
         struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
         struct ene_ub6250_info *info = (struct ene_ub6250_info *) us->extra;
+        u8 *bbuf = info->bbuf;
 
         usb_stor_dbg(us, "transport --- ENE_SDInit\n");
         /* SD Init Part-1 */
@@ -2152,17 +2163,17 @@ static int ene_sd_init(struct us_data *us)
         bcb->Flags              = US_BULK_FLAG_IN;
         bcb->CDB[0]             = 0xF1;
 
-        result = ene_send_scsi_cmd(us, FDIR_READ, &buf, 0);
+        result = ene_send_scsi_cmd(us, FDIR_READ, bbuf, 0);
         if (result != USB_STOR_XFER_GOOD) {
                 usb_stor_dbg(us, "Execution SD Init Code Fail !!\n");
                 return USB_STOR_TRANSPORT_ERROR;
         }
 
-        info->SD_Status =  *(struct SD_STATUS *)&buf[0];
+        info->SD_Status =  *(struct SD_STATUS *) bbuf;
         if (info->SD_Status.Insert && info->SD_Status.Ready) {
                 struct SD_STATUS *s = &info->SD_Status;
 
-                ene_get_card_status(us, (unsigned char *)&buf);
+                ene_get_card_status(us, bbuf);
                 usb_stor_dbg(us, "Insert     = %x\n", s->Insert);
                 usb_stor_dbg(us, "Ready      = %x\n", s->Ready);
                 usb_stor_dbg(us, "IsMMC      = %x\n", s->IsMMC);
@@ -2170,7 +2181,7 @@ static int ene_sd_init(struct us_data *us)
                 usb_stor_dbg(us, "HiSpeed    = %x\n", s->HiSpeed);
                 usb_stor_dbg(us, "WtP        = %x\n", s->WtP);
         } else {
-                usb_stor_dbg(us, "SD Card Not Ready --- %x\n", buf[0]);
+                usb_stor_dbg(us, "SD Card Not Ready --- %x\n", bbuf[0]);
                 return USB_STOR_TRANSPORT_ERROR;
         }
         return USB_STOR_TRANSPORT_GOOD;
@@ -2180,13 +2191,15 @@ static int ene_sd_init(struct us_data *us)
 static int ene_init(struct us_data *us)
 {
         int result;
-        u8  misc_reg03 = 0;
+        u8  misc_reg03;
         struct ene_ub6250_info *info = (struct ene_ub6250_info *)(us->extra);
+        u8 *bbuf = info->bbuf;
 
-        result = ene_get_card_type(us, REG_CARD_STATUS, &misc_reg03);
+        result = ene_get_card_type(us, REG_CARD_STATUS, bbuf);
         if (result != USB_STOR_XFER_GOOD)
                 return USB_STOR_TRANSPORT_ERROR;
 
+        misc_reg03 = bbuf[0];
         if (misc_reg03 & 0x01) {
                 if (!info->SD_Status.Ready) {
                         result = ene_sd_init(us);
@@ -2303,8 +2316,9 @@ static int ene_ub6250_probe(struct usb_interface *intf,
                          const struct usb_device_id *id)
 {
         int result;
-        u8  misc_reg03 = 0;
+        u8  misc_reg03;
         struct us_data *us;
+        struct ene_ub6250_info *info;
 
         result = usb_stor_probe1(&us, intf, id,
                    (id - ene_ub6250_usb_ids) + ene_ub6250_unusual_dev_list,
@@ -2313,11 +2327,16 @@ static int ene_ub6250_probe(struct usb_interface *intf,
                 return result;
 
         /* FIXME: where should the code alloc extra buf ? */
-        if (!us->extra) {
-                us->extra = kzalloc(sizeof(struct ene_ub6250_info), GFP_KERNEL);
-                if (!us->extra)
-                        return -ENOMEM;
-                us->extra_destructor = ene_ub6250_info_destructor;
+        us->extra = kzalloc(sizeof(struct ene_ub6250_info), GFP_KERNEL);
+        if (!us->extra)
+                return -ENOMEM;
+        us->extra_destructor = ene_ub6250_info_destructor;
+
+        info = (struct ene_ub6250_info *)(us->extra);
+        info->bbuf = kmalloc(512, GFP_KERNEL);
+        if (!info->bbuf) {
+                kfree(us->extra);
+                return -ENOMEM;
         }
 
         us->transport_name = "ene_ub6250";
@@ -2329,12 +2348,13 @@ static int ene_ub6250_probe(struct usb_interface *intf,
                 return result;
 
         /* probe card type */
-        result = ene_get_card_type(us, REG_CARD_STATUS, &misc_reg03);
+        result = ene_get_card_type(us, REG_CARD_STATUS, info->bbuf);
         if (result != USB_STOR_XFER_GOOD) {
                 usb_stor_disconnect(intf);
                 return USB_STOR_TRANSPORT_ERROR;
         }
 
+        misc_reg03 = info->bbuf[0];
         if (!(misc_reg03 & 0x01)) {
                 pr_info("ums_eneub6250: This driver only supports SD/MS cards. "
                         "It does not support SM cards.\n");