From owner-dev-commits-src-main@freebsd.org Tue Sep 7 18:05:46 2021 Return-Path: Delivered-To: dev-commits-src-main@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 11F476698C4; Tue, 7 Sep 2021 18:05:46 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4H3tVK6nllz4b5c; Tue, 7 Sep 2021 18:05:45 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id A473C1712E; Tue, 7 Sep 2021 18:05:45 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 187I5jOO070555; Tue, 7 Sep 2021 18:05:45 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 187I5jC0070554; Tue, 7 Sep 2021 18:05:45 GMT (envelope-from git) Date: Tue, 7 Sep 2021 18:05:45 GMT Message-Id: <202109071805.187I5jC0070554@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mark Johnston Subject: git: 686aa9287c6b - main - swap_pager: Handle large swap_pager_reserve() requests MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: markj X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 686aa9287c6b3658daa2ca0ef1917f2e70a6c07e Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-main@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for the main branch of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 07 Sep 2021 18:05:46 -0000 The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=686aa9287c6b3658daa2ca0ef1917f2e70a6c07e commit 686aa9287c6b3658daa2ca0ef1917f2e70a6c07e Author: Mark Johnston AuthorDate: 2021-09-07 18:03:52 +0000 Commit: Mark Johnston CommitDate: 2021-09-07 18:04:50 +0000 swap_pager: Handle large swap_pager_reserve() requests This interface is used solely by md(4) when the MD_RESERVE flag is specified, as in `mdconfig -a -t swap -s 1G -o reserve`. It pre-allocates swap blocks for the entire object. The number of blocks to be reserved is specified as a vm_size_t, but swp_pager_getswapspace() can allocate at most INT_MAX blocks. vm_size_t also seems like the incorrect type to use here it refers only to the size of the VM object, not the size of a mapping. So: - change the type of "size" in swap_pager_reserve() to vm_pindex_t, and - clamp the requested number of blocks for a single swp_pager_getswapspace() call to INT_MAX. Reported by: syzkaller Reviewed by: dougm, alc, kib MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D31875 --- sys/vm/swap_pager.c | 8 +++++--- sys/vm/swap_pager.h | 2 +- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/sys/vm/swap_pager.c b/sys/vm/swap_pager.c index 63f0d22ed705..6d64ff883966 100644 --- a/sys/vm/swap_pager.c +++ b/sys/vm/swap_pager.c @@ -82,6 +82,7 @@ __FBSDID("$FreeBSD$"); #include #include #include +#include #include #include #include @@ -977,15 +978,16 @@ swap_pager_freespace(vm_object_t object, vm_pindex_t start, vm_size_t size) * Returns 0 on success, -1 on failure. */ int -swap_pager_reserve(vm_object_t object, vm_pindex_t start, vm_size_t size) +swap_pager_reserve(vm_object_t object, vm_pindex_t start, vm_pindex_t size) { daddr_t addr, blk, n_free, s_free; - int i, j, n; + vm_pindex_t i, j; + int n; swp_pager_init_freerange(&s_free, &n_free); VM_OBJECT_WLOCK(object); for (i = 0; i < size; i += n) { - n = size - i; + n = MIN(size - i, INT_MAX); blk = swp_pager_getswapspace(&n); if (blk == SWAPBLK_NONE) { swp_pager_meta_free(object, start, i); diff --git a/sys/vm/swap_pager.h b/sys/vm/swap_pager.h index 20ff70acc3d8..6761d4f99ee4 100644 --- a/sys/vm/swap_pager.h +++ b/sys/vm/swap_pager.h @@ -78,7 +78,7 @@ void swap_pager_copy(vm_object_t, vm_object_t, vm_pindex_t, int); vm_pindex_t swap_pager_find_least(vm_object_t object, vm_pindex_t pindex); void swap_pager_swap_init(void); int swap_pager_nswapdev(void); -int swap_pager_reserve(vm_object_t, vm_pindex_t, vm_size_t); +int swap_pager_reserve(vm_object_t, vm_pindex_t, vm_pindex_t); void swap_pager_status(int *total, int *used); u_long swap_pager_swapped_pages(vm_object_t object); void swapoff_all(void);