Messages in this thread Patch in this message | | | Subject | Re: [git pull] vfs.git bits and pieces | From | Joe Perches <> | Date | Wed, 20 Nov 2013 14:24:45 -0800 |
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On Wed, 2013-11-20 at 22:16 +0000, Al Viro wrote: > While digging in the same area: > > Wrong page freed on preallocate_pmds() failure exit > > Note that pmds[i] is simply uninitialized at that point... > Granted, it's very hard to hit (you need split page locks > *and* kmalloc(sizeof(spinlock_t), GFP_KERNEL) failing), > but the code is obviously bogus. > > Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> > --- > diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c > index a7cccb6d..36aa999 100644 > --- a/arch/x86/mm/pgtable.c > +++ b/arch/x86/mm/pgtable.c > @@ -209,7 +209,7 @@ static int preallocate_pmds(pmd_t *pmds[]) > if (!pmd) > failed = true; > if (pmd && !pgtable_pmd_page_ctor(virt_to_page(pmd))) { > - free_page((unsigned long)pmds[i]); > + free_page((unsigned long)pmd); > pmd = NULL; > failed = true; > }
trivia: It'd probably read better with an else too
if (!pmd) { failed = true; } else if (!pgtable_pmd_page_ctor(virt_to_page(pmd))) { etc...
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