Wrong page freed on preallocate_pmds() failure exit

2a46eed5 · Al Viro <[email protected]> · 2013-11-20 22:16:36 +00:00

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.

Introduced by commit 09ef4939850a ("x86: add missed
pgtable_pmd_page_ctor/dtor calls for preallocated pmds")

Signed-off-by: Al Viro <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: 2a46eed54a28c1e3de701ca4237ce4f8bebf14c6
Parents: 82023bb7

Changes

1 files changed · +1 −1

File	Status	Add	Del	Content
arch/x86/mm/pgtable.c	modified	+1	−1	View file

arch/x86/mm/pgtable.c

View file

diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index a7cccb6..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;
 		}