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scsi: sg: sg_read(): get rid of access_ok()/__copy_..._user()

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Use copy_..._user() instead, both in sg_read() and in sg_read_oxfer().  And
don't open-code memdup_user()...

Link: https://lore.kernel.org/r/20191017193925.25539-6-viro@ZenIV.linux.org.uk
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Al Viro 2019-10-17 20:39:23 +01:00 committed by Martin K. Petersen
parent d9fc5617bc
commit c8c12792d5
1 changed files with 6 additions and 12 deletions
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18
drivers/scsi/sg.c
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@ -429,16 +429,10 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
"sg_read: count=%d\n", (int) count));
if (!access_ok(buf, count))
return -EFAULT;
if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
if (!old_hdr)
return -ENOMEM;
if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
retval = -EFAULT;
goto free_old_hdr;
}
old_hdr = memdup_user(buf, SZ_SG_HEADER);
if (IS_ERR(old_hdr))
return PTR_ERR(old_hdr);
if (old_hdr->reply_len < 0) {
if (count >= SZ_SG_IO_HDR) {
sg_io_hdr_t __user *p = (void __user *)buf;
@ -529,7 +523,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
/* Now copy the result back to the user buffer. */
if (count >= SZ_SG_HEADER) {
if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
retval = -EFAULT;
goto free_old_hdr;
}
@ -1960,12 +1954,12 @@ sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
num = 1 << (PAGE_SHIFT + schp->page_order);
for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
if (num > num_read_xfer) {
if (__copy_to_user(outp, page_address(schp->pages[k]),
if (copy_to_user(outp, page_address(schp->pages[k]),
num_read_xfer))
return -EFAULT;
break;
} else {
if (__copy_to_user(outp, page_address(schp->pages[k]),
if (copy_to_user(outp, page_address(schp->pages[k]),
num))
return -EFAULT;
num_read_xfer -= num;