On Mon, Oct 1, 2018 at 9:16 AM Evan Green <evgreen@xxxxxxxxxxxx> wrote: > > From: Robb Glasser <rglasser@xxxxxxxxxx> > > sg_ioctl could be spammed by requests, leading to a double free in > __free_pages. This protects the entry points of sg_ioctl where the > memory could be corrupted by a double call to __free_pages if multiple > requests are happening concurrently. > > Signed-off-by: Robb Glasser <rglasser@xxxxxxxxxx> > Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > Signed-off-by: Evan Green <evgreen@xxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > > --- > Reposting this patch from last summer, as it looks like it fell in between > the cracks. Christoph, do you still feel strongly about: https://lkml.org/lkml/2017/8/5/75 ? > > drivers/scsi/sg.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c > index 8a254bb46a9b..25579d8a16b5 100644 > --- a/drivers/scsi/sg.c > +++ b/drivers/scsi/sg.c > @@ -924,8 +924,10 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) > return -ENXIO; > if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR)) > return -EFAULT; > + mutex_lock(&sfp->parentdp->open_rel_lock); > result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR, > 1, read_only, 1, &srp); > + mutex_unlock(&sfp->parentdp->open_rel_lock); > if (result < 0) > return result; > result = wait_event_interruptible(sfp->read_wait, > -- > 2.19.0.605.g01d371f741-goog > -- Thanks, ~Nick Desaulniers
