On Tue, Feb 12, 2013 at 12:48:58PM -0700, Tim Gardner wrote: > Dynamically allocate the NLM host structure in order to avoid stack overflow. > nlmsvc_mark_resources() is several call levels deep in a stack > that has a number of large variables. 512 bytes seems like a lot > on the stack at this point. > > smatch analysis: > > fs/lockd/svcsubs.c:366 nlmsvc_mark_resources() warn: 'hint' puts > 512 bytes on stack > > Cc: Trond Myklebust <[email protected]> > Cc: "J. Bruce Fields" <[email protected]> > Cc: [email protected] > Signed-off-by: Tim Gardner <[email protected]> > --- > fs/lockd/svcsubs.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c > index b904f41..f3abb7f 100644 > --- a/fs/lockd/svcsubs.c > +++ b/fs/lockd/svcsubs.c > @@ -363,11 +363,15 @@ nlmsvc_is_client(void *data, struct nlm_host *dummy) > void > nlmsvc_mark_resources(struct net *net) > { > - struct nlm_host hint; > + struct nlm_host *hint = kzalloc(sizeof(*hint), GFP_KERNEL); > > - dprintk("lockd: nlmsvc_mark_resources for net %p\n", net); > - hint.net = net; > - nlm_traverse_files(&hint, nlmsvc_mark_host, NULL); > + if (hint) { > + dprintk("lockd: nlmsvc_mark_resources for net %p\n", net); > + hint->net = net; > + nlm_traverse_files(hint, nlmsvc_mark_host, NULL); > + }
Silently neglecting to do this looks like a bad idea. It's strange that we're passing in an nlm_host when all we actually use is the struct net*. Why not just change this to pass in the net instead? --b. > + > + kfree(hint); > } > > /* > -- > 1.7.9.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
