On 2/28/11 8:59 PM, Dave Chinner wrote: > 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. Ok, I can resend, I was going to do that but most of xfs uses the other style so wasn't sure. -Eric _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
