From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933452AbcAMJw4 (ORCPT ); Wed, 13 Jan 2016 04:52:56 -0500 Received: from mail-wm0-f47.google.com ([74.125.82.47]:35713 "EHLO mail-wm0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932190AbcAMJww (ORCPT ); Wed, 13 Jan 2016 04:52:52 -0500 MIME-Version: 1.0 From: Dmitry Vyukov Date: Wed, 13 Jan 2016 10:52:31 +0100 Message-ID: Subject: net/sctp: use-after-free in __sctp_connect To: Vlad Yasevich , Neil Horman , "David S. Miller" , linux-sctp@vger.kernel.org, netdev , LKML , Eric Dumazet , Marcelo Ricardo Leitner Cc: syzkaller , Kostya Serebryany , Alexander Potapenko , Sasha Levin Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, The following program causes use-after-free in __sctp_connect: // autogenerated by syzkaller (http://github.com/google/syzkaller) #include #include #include #include #include long r[13]; void *thr(void *arg) { switch ((long)arg) { case 0: r[0] = syscall(SYS_mmap, 0x20000000ul, 0x20000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul); break; case 1: r[1] = syscall(SYS_socket, 0xaul, 0x1ul, 0x84ul, 0, 0, 0); break; case 2: memcpy((void*)0x2000b000, "\x0a\x00\x33\xe0\x49\xd0\x2e\x70\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x4c\x37\xff\xc4", 28); r[3] = syscall(SYS_bind, r[1], 0x2000b000ul, 0x1cul, 0, 0, 0); break; case 3: r[4] = syscall(SYS_dup2, r[1], r[1], 0, 0, 0, 0); break; case 4: *(uint64_t*)0x200177ed = (uint64_t)0x0; *(uint64_t*)0x200177f5 = (uint64_t)0x2710; r[7] = syscall(SYS_setsockopt, r[4], 0x1ul, 0x15ul, 0x200177edul, 0x10ul, 0); break; case 5: *(uint16_t*)0x2000b008 = (uint16_t)0x2; *(uint16_t*)0x2000b00a = (uint16_t)0xbab; *(uint32_t*)0x2000b00c = (uint32_t)0xffffffff; r[11] = syscall(SYS_setsockopt, r[4], 0x84ul, 0x6eul, 0x2000b000ul, 0x1cul, 0); break; case 6: r[12] = syscall(SYS_shutdown, r[4], 0x1ul, 0, 0, 0, 0); break; } return 0; } int main() { long i; pthread_t th[7]; memset(r, -1, sizeof(r)); for (i = 0; i < 7; i++) { pthread_create(&th[i], 0, thr, (void*)i); usleep(10000); } for (i = 0; i < 7; i++) { pthread_create(&th[i], 0, thr, (void*)i); if (i%2==0) usleep(10000); } usleep(100000); return 0; } ================================================================== BUG: KASAN: use-after-free in __sctp_connect+0xb23/0xb90 at addr ffff8800605febb8 Read of size 4 by task syz-executor/15263 INFO: Allocated in sctp_association_new+0x6f/0x1da0 age=0 cpu=3 pid=15267 [< none >] ___slab_alloc+0x486/0x4e0 mm/slub.c:2468 [< none >] __slab_alloc+0x66/0xc0 mm/slub.c:2497 [< inline >] slab_alloc_node mm/slub.c:2560 [< inline >] slab_alloc mm/slub.c:2602 [< none >] kmem_cache_alloc_trace+0x284/0x310 mm/slub.c:2619 [< inline >] kmalloc include/linux/slab.h:458 [< inline >] kzalloc include/linux/slab.h:602 [< none >] sctp_association_new+0x6f/0x1da0 net/sctp/associola.c:302 [< none >] __sctp_connect+0x4ec/0xb90 net/sctp/socket.c:1161 [< none >] __sctp_setsockopt_connectx+0x198/0x1d0 net/sctp/socket.c:1328 [< inline >] sctp_setsockopt_connectx net/sctp/socket.c:1360 [< none >] sctp_setsockopt+0x226/0x3630 net/sctp/socket.c:3728 [< none >] sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2642 [< inline >] SYSC_setsockopt net/socket.c:1752 [< none >] SyS_setsockopt+0x158/0x240 net/socket.c:1731 [< none >] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 INFO: Freed in sctp_association_put+0x150/0x250 age=0 cpu=3 pid=15267 [< none >] __slab_free+0x1fc/0x320 mm/slub.c:2678 [< inline >] slab_free mm/slub.c:2833 [< none >] kfree+0x2a8/0x2d0 mm/slub.c:3662 [< inline >] sctp_association_destroy net/sctp/associola.c:424 [< none >] sctp_association_put+0x150/0x250 net/sctp/associola.c:860 [< none >] sctp_wait_for_connect+0x37c/0x4f0 net/sctp/socket.c:7067 [< none >] __sctp_connect+0x905/0xb90 net/sctp/socket.c:1215 [< none >] __sctp_setsockopt_connectx+0x198/0x1d0 net/sctp/socket.c:1328 [< inline >] sctp_setsockopt_connectx net/sctp/socket.c:1360 [< none >] sctp_setsockopt+0x226/0x3630 net/sctp/socket.c:3728 [< none >] sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2642 [< inline >] SYSC_setsockopt net/socket.c:1752 [< none >] SyS_setsockopt+0x158/0x240 net/socket.c:1731 [< none >] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 INFO: Slab 0xffffea0001817e00 objects=7 used=3 fp=0xffff8800605fa3b0 flags=0x5fffc0000004080 INFO: Object 0xffff8800605feb10 @offset=27408 fp=0x (null) CPU: 2 PID: 15263 Comm: syz-executor Tainted: G B 4.4.0+ #237 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 00000000ffffffff ffff88003717f8f0 ffffffff8290ea2d ffff88003e806a00 ffff8800605feb10 ffff8800605f8000 ffff88003717f920 ffffffff81730904 ffff88003e806a00 ffffea0001817e00 ffff8800605feb10 dffffc0000000000 Call Trace: [] __asan_report_load4_noabort+0x3e/0x40 mm/kasan/report.c:294 [] __sctp_connect+0xb23/0xb90 net/sctp/socket.c:1217 [] __sctp_setsockopt_connectx+0x198/0x1d0 net/sctp/socket.c:1328 [< inline >] sctp_setsockopt_connectx net/sctp/socket.c:1360 [] sctp_setsockopt+0x226/0x3630 net/sctp/socket.c:3728 [] sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2642 [< inline >] SYSC_setsockopt net/socket.c:1752 [] SyS_setsockopt+0x158/0x240 net/socket.c:1731 [] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 ================================================================== On commit 03891f9c853d5c4473224478a1e03ea00d70ff8d (Jan 11).