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authorAl Viro <viro@zeniv.linux.org.uk>2019-10-17 20:39:21 +0100
committerMartin K. Petersen <martin.petersen@oracle.com>2019-11-06 00:04:03 -0500
commitc35a5cfb41509c2214228aa321509ffd91cbf063 (patch)
treed048d4a53a89eb168c390cf9e1d79b12ddd9312d /drivers/scsi/sg.c
parent062c9d4527ccbdbf49139607efd44c9c3f82a2fd (diff)
scsi: sg: sg_read(): simplify reading ->pack_id of userland sg_io_hdr_t
We don't need to allocate a temporary buffer and read the entire structure in it, only to fetch a single field and free what we'd allocated. Just use get_user() and be done with it... Link: https://lore.kernel.org/r/20191017193925.25539-4-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>
Diffstat (limited to 'drivers/scsi/sg.c')
-rw-r--r--drivers/scsi/sg.c13
1 files changed, 2 insertions, 11 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 4c62237cdf37..2d30e89075e9 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -441,17 +441,8 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
}
if (old_hdr->reply_len < 0) {
if (count >= SZ_SG_IO_HDR) {
- sg_io_hdr_t *new_hdr;
- new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
- if (!new_hdr) {
- retval = -ENOMEM;
- goto free_old_hdr;
- }
- retval =__copy_from_user
- (new_hdr, buf, SZ_SG_IO_HDR);
- req_pack_id = new_hdr->pack_id;
- kfree(new_hdr);
- if (retval) {
+ sg_io_hdr_t __user *p = (void __user *)buf;
+ if (get_user(req_pack_id, &p->pack_id)) {
retval = -EFAULT;
goto free_old_hdr;
}