From 85ba94ba0592296053f7f2846812173424afe1cb Mon Sep 17 00:00:00 2001 From: Matt Mackall Date: Tue, 7 Oct 2008 11:37:35 -0500 Subject: [PATCH] SLOB: fix bogus ksize calculation SLOB's ksize calculation was braindamaged and generally harmlessly underreported the allocation size. But for very small buffers, it could in fact overreport them, leading code depending on krealloc to overrun the allocation and trample other data. Signed-off-by: Matt Mackall Tested-by: Peter Zijlstra Signed-off-by: Linus Torvalds --- mm/slob.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/slob.c b/mm/slob.c index 4c82dd41f32..62b679dc660 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -515,7 +515,7 @@ size_t ksize(const void *block) sp = (struct slob_page *)virt_to_page(block); if (slob_page(sp)) - return ((slob_t *)block - 1)->units + SLOB_UNIT; + return (((slob_t *)block - 1)->units - 1) * SLOB_UNIT; else return sp->page.private; } -- 2.20.1