Module Name: src Committed By: maxv Date: Mon Mar 11 20:38:28 UTC 2019
Modified Files: src/sys/kern: subr_pool.c Log Message: Add sanity check: make sure we retrieve a valid item header, by checking its page address against the one we computed. If there's a mismatch it means the buffer does not belong to the pool, and we panic. To generate a diff of this commit: cvs rdiff -u -r1.234 -r1.235 src/sys/kern/subr_pool.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
Modified files: Index: src/sys/kern/subr_pool.c diff -u src/sys/kern/subr_pool.c:1.234 src/sys/kern/subr_pool.c:1.235 --- src/sys/kern/subr_pool.c:1.234 Mon Mar 11 20:21:32 2019 +++ src/sys/kern/subr_pool.c Mon Mar 11 20:38:27 2019 @@ -1,4 +1,4 @@ -/* $NetBSD: subr_pool.c,v 1.234 2019/03/11 20:21:32 maxv Exp $ */ +/* $NetBSD: subr_pool.c,v 1.235 2019/03/11 20:38:27 maxv Exp $ */ /* * Copyright (c) 1997, 1999, 2000, 2002, 2007, 2008, 2010, 2014, 2015, 2018 @@ -33,7 +33,7 @@ */ #include <sys/cdefs.h> -__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.234 2019/03/11 20:21:32 maxv Exp $"); +__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.235 2019/03/11 20:38:27 maxv Exp $"); #ifdef _KERNEL_OPT #include "opt_ddb.h" @@ -431,7 +431,12 @@ pr_find_pagehead(struct pool *pp, void * (void *)((uintptr_t)v & pp->pr_alloc->pa_pagemask); if ((pp->pr_roflags & PR_PHINPAGE) != 0) { - ph = (struct pool_item_header *)((char *)page + pp->pr_phoffset); + ph = (struct pool_item_header *) + ((char *)page + pp->pr_phoffset); + if (__predict_false((void *)ph->ph_page != page)) { + panic("%s: [%s] item not part of pool", + __func__, pp->pr_wchan); + } } else { tmp.ph_page = page; ph = SPLAY_FIND(phtree, &pp->pr_phtree, &tmp);