sg_write()/bsg_write() is not fit to be called under KERNEL_DS
authorAl Viro <viro@zeniv.linux.org.uk>
Fri, 16 Dec 2016 18:42:06 +0000 (13:42 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 9 Jan 2017 07:07:53 +0000 (08:07 +0100)
commitd85727365859108cbcf832c2b3c38358ddc7638b
tree2c30a467ab254d1e2aae3e405d1ac3c6d1de05a9
parent7fb5a936457dff3616644d1725f28002048819f7
sg_write()/bsg_write() is not fit to be called under KERNEL_DS

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 <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
block/bsg.c
drivers/scsi/sg.c