From 3e3267311e3b6557206f293eeb9205b41e090625 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 16 Dec 2016 13:42:06 -0500 Subject: sg_write()/bsg_write() is not fit to be called under KERNEL_DS [ Upstream commit 128394eff343fc6d2f32172f03e24829539c5835 ] Both damn things interpret userland pointers embedded into the payload; worse, they are actually traversing those. Leaving aside the bad API design, this is very much _not_ safe to call with KERNEL_DS. Bail out early if that happens. Cc: stable@vger.kernel.org Signed-off-by: Al Viro Signed-off-by: Sasha Levin --- drivers/scsi/sg.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers') diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index ec192939750e..26bc4e9c7441 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -592,6 +592,9 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) sg_io_hdr_t *hp; unsigned char cmnd[SG_MAX_CDB_SIZE]; + if (unlikely(segment_eq(get_fs(), KERNEL_DS))) + return -EINVAL; + if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))) return -ENXIO; SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, -- cgit v1.2.3