From: Al Viro <[email protected]> ... just use copy_from_user(). We copy only SZ_SG_IO_HDR bytes, so that would, strictly speaking, loosen the check. However, for call chains via ->write() the caller has actually checked the entire range and SG_IO passes exactly SZ_SG_IO_HDR for count. So no visible behaviour changes happen if we check only what we really need for copyin.
Signed-off-by: Al Viro <[email protected]> --- drivers/scsi/sg.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 2d30e89075e9..3702f66493f7 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -717,8 +717,6 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf, if (count < SZ_SG_IO_HDR) return -EINVAL; - if (!access_ok(buf, count)) - return -EFAULT; /* protects following copy_from_user()s + get_user()s */ sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */ if (!(srp = sg_add_request(sfp))) { @@ -728,7 +726,7 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf, } srp->sg_io_owned = sg_io_owned; hp = &srp->header; - if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) { + if (copy_from_user(hp, buf, SZ_SG_IO_HDR)) { sg_remove_request(sfp, srp); return -EFAULT; } -- 2.11.0
