From: Al Viro <v...@zeniv.linux.org.uk>

Just use plain copy_from_user() and get_user().  Note that while
a buf-derived pointer gets stored into ->dxferp, all places that
actually use the resulting value feed it either to import_iovec()
or to import_single_range(), and both will do validation.

Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
---
 drivers/scsi/sg.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 9f6534a025cd..f3d090b93cdf 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -612,11 +612,9 @@ sg_write(struct file *filp, const char __user *buf, size_t 
count, loff_t * ppos)
              scsi_block_when_processing_errors(sdp->device)))
                return -ENXIO;
 
-       if (!access_ok(buf, count))
-               return -EFAULT; /* protects following copy_from_user()s + 
get_user()s */
        if (count < SZ_SG_HEADER)
                return -EIO;
-       if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
+       if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
                return -EFAULT;
        blocking = !(filp->f_flags & O_NONBLOCK);
        if (old_hdr.reply_len < 0)
@@ -626,7 +624,7 @@ sg_write(struct file *filp, const char __user *buf, size_t 
count, loff_t * ppos)
                return -EIO;    /* The minimum scsi command length is 6 bytes. 
*/
 
        buf += SZ_SG_HEADER;
-       if (__get_user(opcode, buf))
+       if (get_user(opcode, buf))
                return -EFAULT;
 
        if (!(srp = sg_add_request(sfp))) {
@@ -676,7 +674,7 @@ sg_write(struct file *filp, const char __user *buf, size_t 
count, loff_t * ppos)
        hp->flags = input_size; /* structure abuse ... */
        hp->pack_id = old_hdr.pack_id;
        hp->usr_ptr = NULL;
-       if (__copy_from_user(cmnd, buf, cmd_size))
+       if (copy_from_user(cmnd, buf, cmd_size))
                return -EFAULT;
        /*
         * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
-- 
2.11.0

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