From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751568AbdCCLHi (ORCPT ); Fri, 3 Mar 2017 06:07:38 -0500 Received: from mail-ua0-f178.google.com ([209.85.217.178]:33318 "EHLO mail-ua0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751323AbdCCLHf (ORCPT ); Fri, 3 Mar 2017 06:07:35 -0500 MIME-Version: 1.0 In-Reply-To: References: From: Dmitry Vyukov Date: Fri, 3 Mar 2017 12:07:04 +0100 Message-ID: Subject: Re: net/kcm: use-after-free in kcm_wq To: David Miller , Tom Herbert , Cong Wang , Al Viro , Daniel Borkmann , netdev , LKML , Eric Dumazet Cc: syzkaller Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id v23B7hMo005147 On Fri, Mar 3, 2017 at 11:11 AM, Dmitry Vyukov wrote: > On Fri, Mar 3, 2017 at 11:09 AM, Dmitry Vyukov wrote: >> Hello, >> >> I am getting the following use-after-free reports while running >> syzkaller fuzzer on 86292b33d4b79ee03e2f43ea0381ef85f077c760. Seems >> that work items are not properly cancelled. >> >> ================================================================== >> BUG: KASAN: use-after-free in worker_thread+0x190f/0x1990 >> kernel/workqueue.c:2228 at addr ffff880063de5a20 >> Read of size 8 by task kworker/u8:0/5 >> CPU: 1 PID: 5 Comm: kworker/u8:0 Not tainted 4.10.0+ #260 >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 >> Call Trace: >> __dump_stack lib/dump_stack.c:15 [inline] >> dump_stack+0x2ee/0x3ef lib/dump_stack.c:51 >> kasan_object_err+0x1c/0x70 mm/kasan/report.c:166 >> print_address_description mm/kasan/report.c:204 [inline] >> kasan_report_error mm/kasan/report.c:288 [inline] >> kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310 >> kasan_report mm/kasan/report.c:331 [inline] >> __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331 >> worker_thread+0x190f/0x1990 kernel/workqueue.c:2228 >> kthread+0x326/0x3f0 kernel/kthread.c:227 >> ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430 >> Object at ffff880063de5900, in cache kcm_psock_cache size: 616 >> Allocated: >> PID = 11085 >> save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 >> save_stack+0x43/0xd0 mm/kasan/kasan.c:502 >> set_track mm/kasan/kasan.c:514 [inline] >> kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605 >> kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544 >> kmem_cache_alloc+0x102/0x680 mm/slab.c:3571 >> kmem_cache_zalloc include/linux/slab.h:653 [inline] >> kcm_attach net/kcm/kcmsock.c:1384 [inline] >> kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline] >> kcm_ioctl+0x303/0x1800 net/kcm/kcmsock.c:1690 >> sock_do_ioctl+0x65/0xb0 net/socket.c:895 >> sock_ioctl+0x2c2/0x440 net/socket.c:993 >> vfs_ioctl fs/ioctl.c:43 [inline] >> do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683 >> SYSC_ioctl fs/ioctl.c:698 [inline] >> SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689 >> entry_SYSCALL_64_fastpath+0x1f/0xc2 >> Freed: >> PID = 11095 >> save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 >> save_stack+0x43/0xd0 mm/kasan/kasan.c:502 >> set_track mm/kasan/kasan.c:514 [inline] >> kasan_slab_free+0x6f/0xb0 mm/kasan/kasan.c:578 >> __cache_free mm/slab.c:3513 [inline] >> kmem_cache_free+0x71/0x240 mm/slab.c:3773 >> kcm_unattach+0xee7/0x1520 net/kcm/kcmsock.c:1558 >> kcm_unattach_ioctl net/kcm/kcmsock.c:1603 [inline] >> kcm_ioctl+0xfae/0x1800 net/kcm/kcmsock.c:1700 >> sock_do_ioctl+0x65/0xb0 net/socket.c:895 >> sock_ioctl+0x2c2/0x440 net/socket.c:993 >> vfs_ioctl fs/ioctl.c:43 [inline] >> do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683 >> SYSC_ioctl fs/ioctl.c:698 [inline] >> SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689 >> entry_SYSCALL_64_fastpath+0x1f/0xc2 >> Memory state around the buggy address: >> ffff880063de5900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ffff880063de5980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >>>ffff880063de5a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ^ >> ffff880063de5a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ffff880063de5b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc >> ================================================================== >> >> >> ================================================================== >> BUG: KASAN: use-after-free in worker_thread+0x190f/0x1990 >> kernel/workqueue.c:2228 at addr ffff88005378ed20 >> Read of size 8 by task kworker/u8:2/6942 >> CPU: 3 PID: 6942 Comm: kworker/u8:2 Not tainted 4.10.0+ #260 >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 >> Call Trace: >> __dump_stack lib/dump_stack.c:15 [inline] >> dump_stack+0x2ee/0x3ef lib/dump_stack.c:51 >> kasan_object_err+0x1c/0x70 mm/kasan/report.c:166 >> print_address_description mm/kasan/report.c:204 [inline] >> kasan_report_error mm/kasan/report.c:288 [inline] >> kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310 >> kasan_report mm/kasan/report.c:331 [inline] >> __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331 >> worker_thread+0x190f/0x1990 kernel/workqueue.c:2228 >> kthread+0x326/0x3f0 kernel/kthread.c:227 >> ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430 >> Object at ffff88005378ec00, in cache kcm_psock_cache size: 616 >> Allocated: >> PID = 3023 >> save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 >> save_stack+0x43/0xd0 mm/kasan/kasan.c:502 >> set_track mm/kasan/kasan.c:514 [inline] >> kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605 >> kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544 >> kmem_cache_alloc+0x102/0x680 mm/slab.c:3571 >> kmem_cache_zalloc include/linux/slab.h:653 [inline] >> kcm_attach net/kcm/kcmsock.c:1384 [inline] >> kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline] >> kcm_ioctl+0x303/0x1800 net/kcm/kcmsock.c:1690 >> sock_do_ioctl+0x65/0xb0 net/socket.c:895 >> sock_ioctl+0x2c2/0x440 net/socket.c:993 >> vfs_ioctl fs/ioctl.c:43 [inline] >> do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683 >> SYSC_ioctl fs/ioctl.c:698 [inline] >> SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689 >> entry_SYSCALL_64_fastpath+0x1f/0xc2 >> Freed: >> PID = 6942 >> save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 >> save_stack+0x43/0xd0 mm/kasan/kasan.c:502 >> set_track mm/kasan/kasan.c:514 [inline] >> kasan_slab_free+0x6f/0xb0 mm/kasan/kasan.c:578 >> __cache_free mm/slab.c:3513 [inline] >> kmem_cache_free+0x71/0x240 mm/slab.c:3773 >> unreserve_psock+0x585/0x760 net/kcm/kcmsock.c:545 >> kcm_write_msgs+0xbba/0x1b90 net/kcm/kcmsock.c:588 >> kcm_tx_work+0x2e/0x190 net/kcm/kcmsock.c:729 >> process_one_work+0xbd0/0x1c10 kernel/workqueue.c:2096 >> worker_thread+0x223/0x1990 kernel/workqueue.c:2230 >> kthread+0x326/0x3f0 kernel/kthread.c:227 >> ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430 >> Memory state around the buggy address: >> ffff88005378ec00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ffff88005378ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >>>ffff88005378ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ^ >> ffff88005378ed80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ffff88005378ee00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc >> ================================================================== > > > > Also like this one: > > ================================================================== > BUG: KASAN: use-after-free in atomic_long_read > include/linux/compiler.h:254 [inline] at addr ffff8800538aba60 > BUG: KASAN: use-after-free in get_work_pool+0x2f2/0x340 > kernel/workqueue.c:709 at addr ffff8800538aba60 > Read of size 8 by task syz-executor6/7965 > CPU: 2 PID: 7965 Comm: syz-executor6 Not tainted 4.10.0+ #248 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:15 [inline] > dump_stack+0x2ee/0x3ef lib/dump_stack.c:51 > kasan_object_err+0x1c/0x70 mm/kasan/report.c:166 > print_address_description mm/kasan/report.c:204 [inline] > kasan_report_error mm/kasan/report.c:288 [inline] > kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310 > kasan_report mm/kasan/report.c:331 [inline] > __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331 > atomic_long_read include/linux/compiler.h:254 [inline] > get_work_pool+0x2f2/0x340 kernel/workqueue.c:709 > __queue_work+0x2b3/0x1210 kernel/workqueue.c:1401 > queue_work_on+0x2e9/0x330 kernel/workqueue.c:1486 > queue_work include/linux/workqueue.h:487 [inline] > strp_check_rcv+0x25/0x30 net/strparser/strparser.c:494 > kcm_attach net/kcm/kcmsock.c:1434 [inline] > kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline] > kcm_ioctl+0x8bb/0x1800 net/kcm/kcmsock.c:1690 > sock_do_ioctl+0x65/0xb0 net/socket.c:895 > sock_ioctl+0x2c2/0x440 net/socket.c:993 > vfs_ioctl fs/ioctl.c:43 [inline] > do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683 > SYSC_ioctl fs/ioctl.c:698 [inline] > SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689 > entry_SYSCALL_64_fastpath+0x1f/0xc2 > RIP: 0033:0x4458d9 > RSP: 002b:00007f1dce9d1b58 EFLAGS: 00000286 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 0000000000000024 RCX: 00000000004458d9 > RDX: 0000000020b68000 RSI: 00000000000089e0 RDI: 0000000000000024 > RBP: 00000000006e0220 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000286 R12: 00000000007080a8 > R13: 0000000000000000 R14: 00007f1dce9d29c0 R15: 00007f1dce9d2700 > Object at ffff8800538ab940, in cache kcm_psock_cache size: 616 > Allocated: > PID = 7965 > save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 > save_stack+0x43/0xd0 mm/kasan/kasan.c:502 > set_track mm/kasan/kasan.c:514 [inline] > kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605 > kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544 > kmem_cache_alloc+0x102/0x680 mm/slab.c:3571 > kmem_cache_zalloc include/linux/slab.h:653 [inline] > kcm_attach net/kcm/kcmsock.c:1384 [inline] > kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline] > kcm_ioctl+0x303/0x1800 net/kcm/kcmsock.c:1690 > sock_do_ioctl+0x65/0xb0 net/socket.c:895 > sock_ioctl+0x2c2/0x440 net/socket.c:993 > vfs_ioctl fs/ioctl.c:43 [inline] > do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683 > SYSC_ioctl fs/ioctl.c:698 [inline] > SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689 > entry_SYSCALL_64_fastpath+0x1f/0xc2 > Freed: > PID = 7982 > save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 > save_stack+0x43/0xd0 mm/kasan/kasan.c:502 > set_track mm/kasan/kasan.c:514 [inline] > kasan_slab_free+0x6f/0xb0 mm/kasan/kasan.c:578 > __cache_free mm/slab.c:3513 [inline] > kmem_cache_free+0x71/0x240 mm/slab.c:3773 > kcm_unattach+0xee7/0x1520 net/kcm/kcmsock.c:1558 > kcm_unattach_ioctl net/kcm/kcmsock.c:1603 [inline] > kcm_ioctl+0xfae/0x1800 net/kcm/kcmsock.c:1700 > sock_do_ioctl+0x65/0xb0 net/socket.c:895 > sock_ioctl+0x2c2/0x440 net/socket.c:993 > vfs_ioctl fs/ioctl.c:43 [inline] > do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683 > SYSC_ioctl fs/ioctl.c:698 [inline] > SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689 > entry_SYSCALL_64_fastpath+0x1f/0xc2 > Memory state around the buggy address: > ffff8800538ab900: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb > ffff8800538ab980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >>ffff8800538aba00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff8800538aba80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8800538abb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== FTR, this is reproducible by running the following syzkaller program: mmap(&(0x7f0000000000/0xfbb000)=nil, (0xfbb000), 0x3, 0x32, 0xffffffffffffffff, 0x0) r0 = socket(0x0, 0x0, 0x0) r1 = socket(0xa, 0x1, 0x0) setsockopt$NETROM_N2(r1, 0x103, 0x3, &(0x7f000072a000)=0x7, 0x4) r2 = bpf$PROG_LOAD(0x5, &(0x7f0000b50000-0x30)={0x1, 0x2, &(0x7f0000b4f000)=[@generic={0xffffffffffffffb7, 0x0, 0x0, 0x0}, @generic={0x9595, 0x0, 0x0, 0x0}], &(0x7f000015a000)="008b", 0x9, 0x80, &(0x7f0000b4f000)="0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000", 0x0}, 0x30) pread64(r1, &(0x7f0000fb8000)="", 0x0, 0x38) mmap(&(0x7f0000fbb000/0x1000)=nil, (0x1000), 0x3, 0x32, 0xffffffffffffffff, 0x0) setsockopt$SCTP_AUTO_ASCONF(r1, 0x84, 0x1e, &(0x7f0000fbc000-0x4)=0x7, 0x4) r3 = dup3(r0, r1, 0x0) ioctl$UFFDIO_API(r2, 0xc018aa3f, &(0x7f000073d000)={0xaa, 0x0, 0x0}) recvmsg$kcm(r3, &(0x7f0000fb9000)={0x0, 0x0, &(0x7f0000fba000-0x40)=[{&(0x7f00001c0000)="", 0x0}, {&(0x7f0000fba000-0x43)="", 0x0}, {&(0x7f00009ec000)="", 0x0}, {&(0x7f0000fb9000)="", 0x0}], 0x4, &(0x7f0000fba000-0xd6)="", 0x0, 0x7}, 0x2) bpf$PROG_LOAD(0x5, &(0x7f0000fb8000)={0x80, 0x1, &(0x7f0000302000-0x28)=[@generic={0x0, 0xc00000, 0x0, 0x0}], &(0x7f0000a85000)="008b", 0x0, 0x0, &(0x7f0000fb5000)="", 0x9}, 0x30) r4 = socket$kcm(0x29, 0x5, 0x0) write(r4, &(0x7f0000fb3000-0xe9)="", 0x0) ioctl$SIOCSIFHWADDR(r3, 0x8924, &(0x7f00008d8000)={"4682049c0228afcdfa4945e37a244a3a", @data="ecefff20cec4768429383ab454036dad"}) ioctl$TUNSETPERSIST(r3, 0x400454cb, &(0x7f0000fbb000-0x4)=0x1) mmap(&(0x7f0000fbc000/0x1000)=nil, (0x1000), 0x3, 0x32, 0xffffffffffffffff, 0x0) mmap(&(0x7f0000fbc000/0x1000)=nil, (0x1000), 0x3, 0x32, 0xffffffffffffffff, 0x0) getsockopt$dccp6_int(r3, 0x21, 0x1, &(0x7f0000fbc000)=0x0, &(0x7f0000fbd000-0x4)=0x4) ioctl$SIOCKCMATTACH(r4, 0x89e0, &(0x7f0000b5c000)={r1, r2}) ioctl$SIOCKCMUNATTACH(r4, 0x89e1, &(0x7f0000fb5000)={r1})