Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754099AbdIEBkz (ORCPT ); Mon, 4 Sep 2017 21:40:55 -0400 Received: from ipmail06.adl2.internode.on.net ([150.101.137.129]:2776 "EHLO ipmail06.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754065AbdIEBky (ORCPT ); Mon, 4 Sep 2017 21:40:54 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A2B3AgA+/61Z//yBpztdGgEBAQECAQEBAQgBAQEBhASBT48Lj2gBAQEBAQEFAYEmAZg9hUQCAoR2AQIBAQEBAQJrKIVGLyMYGGoDNIokDLIlOowFgyqDCYIqh2aBA4UoBYoGhyKPTJREknwClmJXgQ0yIQgcFYURAQEIRhyBeS42iHWCQQEBAQ From: Dave Chinner To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Subject: [PATCH] swapon: fix vfree() badness Date: Tue, 5 Sep 2017 11:40:51 +1000 Message-Id: <20170905014051.11112-1-david@fromorbit.com> X-Mailer: git-send-email 2.13.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2358 Lines: 54 From: Dave Chinner The cluster_info structure is allocated with kvzalloc(), which can return kmalloc'd or vmalloc'd memory. It must be paired with kvfree(), but sys_swapon uses vfree(), resultin in this warning from xfstests generic/357: [ 1985.294915] swapon: swapfile has holes [ 1985.296012] Trying to vfree() bad address (ffff88011569ac00) [ 1985.297769] ------------[ cut here ]------------ [ 1985.299017] WARNING: CPU: 4 PID: 980 at mm/vmalloc.c:1521 __vunmap+0x97/0xb0 [ 1985.300868] CPU: 4 PID: 980 Comm: swapon Tainted: G W 4.13.0-dgc #55 [ 1985.303086] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 1985.305421] task: ffff88083599c800 task.stack: ffffc90006d68000 [ 1985.306896] RIP: 0010:__vunmap+0x97/0xb0 [ 1985.307866] RSP: 0018:ffffc90006d6be68 EFLAGS: 00010296 [ 1985.309300] RAX: 0000000000000030 RBX: ffff88011569ac00 RCX: 0000000000000000 [ 1985.311066] RDX: ffff88013fc949d8 RSI: ffff88013fc8cb98 RDI: ffff88013fc8cb98 [ 1985.312803] RBP: ffffc90006d6be80 R08: 000000000004844c R09: 0000000000001578 [ 1985.314672] R10: ffffffff82271b20 R11: ffffffff8256e16d R12: 000000000000000a [ 1985.316444] R13: 0000000000000001 R14: 00000000ffffffea R15: ffff880139a96000 [ 1985.318230] FS: 00007fb23ac0e880(0000) GS:ffff88013fc80000(0000) knlGS:0000000000000000 [ 1985.320081] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1985.321503] CR2: 0000564cdb0c7000 CR3: 0000000137448000 CR4: 00000000000406e0 [ 1985.323140] Call Trace: [ 1985.323727] vfree+0x2e/0x70 [ 1985.324403] SyS_swapon+0x433/0x1080 [ 1985.325365] entry_SYSCALL_64_fastpath+0x1a/0xa5 Fix this as well as the memory leak caused by a missing kvfree(frontswap_map) in the error handling code. cc: Signed-Off-By: Dave Chinner --- mm/swapfile.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 6ba4aab2db0b..a8952b6563c6 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3052,7 +3052,8 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) p->flags = 0; spin_unlock(&swap_lock); vfree(swap_map); - vfree(cluster_info); + kvfree(cluster_info); + kvfree(frontswap_map); if (swap_file) { if (inode && S_ISREG(inode->i_mode)) { inode_unlock(inode); -- 2.13.3