On Mon, Feb 28, 2011 at 07:37:50PM -0600, Eric Sandeen wrote: > commit 493f3358cb289ccf716c5a14fa5bb52ab75943e5 added: > > + memset(geo, 0, sizeof(*geo)); > > but unfortunately we're dealing with a cast pointer here, and > the caller may actually have a smaller structure on the stack. > Zeroing out more leads to stack corruption traps: > > Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: f87aca93 > > Pid: 262, comm: xfs_fsr Not tainted 2.6.38-rc6-493f3358cb2+ #1 > Call Trace: > > [<c12991ac>] ? panic+0x50/0x150 > [<c102ed71>] ? __stack_chk_fail+0x10/0x18 > [<f87aca93>] ? xfs_ioc_fsgeometry_v1+0x56/0x5d [xfs] > > Fix this by zeroing out the structure in the callers, where we know > the actual size. > > Reported-by: Jeffrey Hundstad <jeffrey.hundstad@xxxxxxxx> > Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> > --- > > diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c > index f5e2a19..34e401f 100644 > --- a/fs/xfs/linux-2.6/xfs_ioctl.c > +++ b/fs/xfs/linux-2.6/xfs_ioctl.c > @@ -698,6 +698,7 @@ xfs_ioc_fsgeometry_v1( > xfs_fsop_geom_v1_t fsgeo; > int error; > > + memset(&fsgeo, 0, sizeof(xfs_fsop_geom_v1_t)); I'd prefer that sizeof(fsgeo) is used here. That means if the type is changed, then memset doesn't need to be. Same for all the rest of the memset calls. Otherwise, Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx> Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
