4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Al Viro <v...@zeniv.linux.org.uk>
commit 128394eff343fc6d2f32172f03e24829539c5835 upstream.
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.
Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
block/bsg.c | 3 +++
drivers/scsi/sg.c | 3 +++
2 files changed, 6 insertions(+)
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -655,6 +655,9 @@ bsg_write(struct file *file, const char
dprintk("%s: write %Zd bytes\n", bd->name, count);
+ if (unlikely(segment_eq(get_fs(), KERNEL_DS)))
+ return -EINVAL;
+
bsg_set_block(bd, file);
bytes_written = 0;
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -592,6 +592,9 @@ sg_write(struct file *filp, const char _
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,
