From: Ard Biesheuvel Subject: Re: KASAN: use-after-free Read in generic_gcmaes_encrypt Date: Thu, 27 Sep 2018 10:35:48 +0200 Message-ID: References: <000000000000d014010576cc00f4@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: "David S. Miller" , Herbert Xu , "H. Peter Anvin" , "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" , Linux Kernel Mailing List , Ingo Molnar , syzkaller-bugs , Thomas Gleixner , "the arch/x86 maintainers" To: syzbot+6d3612ba5e254e387153@syzkaller.appspotmail.com, Steffen Klassert Return-path: In-Reply-To: <000000000000d014010576cc00f4@google.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org (+ Stefan) On Wed, 26 Sep 2018 at 22:24, syzbot wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 739d0def85ca Merge branch 'hv_netvsc-Support-LRO-RSC-in-th.. > git tree: net-next > console output: https://syzkaller.appspot.com/x/log.txt?x=1146ffae400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=e79b9299baeb2298 > dashboard link: https://syzkaller.appspot.com/bug?extid=6d3612ba5e254e387153 > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16200b9e400000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=102311c6400000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+6d3612ba5e254e387153@syzkaller.appspotmail.com > > random: sshd: uninitialized urandom read (32 bytes read) > ================================================================== > BUG: KASAN: use-after-free in memcpy include/linux/string.h:345 [inline] > BUG: KASAN: use-after-free in generic_gcmaes_encrypt+0xc6/0x186 > arch/x86/crypto/aesni-intel_glue.c:1291 > Read of size 12 at addr ffff8801d7ad0900 by task kworker/0:1/14 > > CPU: 0 PID: 14 Comm: kworker/0:1 Not tainted 4.19.0-rc4+ #228 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Workqueue: pencrypt padata_parallel_worker > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113 > print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 > check_memory_region_inline mm/kasan/kasan.c:260 [inline] > check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 > memcpy+0x23/0x50 mm/kasan/kasan.c:302 > memcpy include/linux/string.h:345 [inline] > generic_gcmaes_encrypt+0xc6/0x186 arch/x86/crypto/aesni-intel_glue.c:1291 > crypto_aead_encrypt include/crypto/aead.h:335 [inline] > gcmaes_wrapper_encrypt+0x162/0x200 arch/x86/crypto/aesni-intel_glue.c:1127 > crypto_aead_encrypt include/crypto/aead.h:335 [inline] > pcrypt_aead_enc+0xcb/0x190 crypto/pcrypt.c:143 > padata_parallel_worker+0x49d/0x760 kernel/padata.c:86 > process_one_work+0xc90/0x1b90 kernel/workqueue.c:2153 > worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 > kthread+0x35a/0x420 kernel/kthread.c:246 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 > > Allocated by task 5474: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 > kmem_cache_alloc_trace+0x152/0x750 mm/slab.c:3620 > kmalloc include/linux/slab.h:513 [inline] > tls_set_sw_offload+0xcc4/0x14b0 net/tls/tls_sw.c:1741 > do_tls_setsockopt_conf net/tls/tls_main.c:467 [inline] > do_tls_setsockopt net/tls/tls_main.c:514 [inline] > tls_setsockopt+0x689/0x770 net/tls/tls_main.c:533 > sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3038 > __sys_setsockopt+0x1ba/0x3c0 net/socket.c:1902 > __do_sys_setsockopt net/socket.c:1913 [inline] > __se_sys_setsockopt net/socket.c:1910 [inline] > __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Freed by task 5472: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 > __cache_free mm/slab.c:3498 [inline] > kfree+0xcf/0x230 mm/slab.c:3813 > tls_sk_proto_close+0x5fd/0x750 net/tls/tls_main.c:277 > inet_release+0x104/0x1f0 net/ipv4/af_inet.c:428 > inet6_release+0x50/0x70 net/ipv6/af_inet6.c:458 > __sock_release+0xd7/0x250 net/socket.c:579 > sock_close+0x19/0x20 net/socket.c:1141 > __fput+0x385/0xa30 fs/file_table.c:278 > ____fput+0x15/0x20 fs/file_table.c:309 > task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:193 [inline] > exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 > prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] > syscall_return_slowpath arch/x86/entry/common.c:268 [inline] > do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8801d7ad0900 > which belongs to the cache kmalloc-32 of size 32 > The buggy address is located 0 bytes inside of > 32-byte region [ffff8801d7ad0900, ffff8801d7ad0920) > The buggy address belongs to the page: > page:ffffea00075eb400 count:1 mapcount:0 mapping:ffff8801da8001c0 > index:0xffff8801d7ad0fc1 > flags: 0x2fffc0000000100(slab) > raw: 02fffc0000000100 ffffea00075eb948 ffffea00075ff688 ffff8801da8001c0 > raw: ffff8801d7ad0fc1 ffff8801d7ad0000 000000010000003f 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801d7ad0800: fb fb fb fb fc fc fc fc 00 00 fc fc fc fc fc fc > ffff8801d7ad0880: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc > > ffff8801d7ad0900: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc > ^ > ffff8801d7ad0980: fb fb fb fb fc fc fc fc 00 00 fc fc fc fc fc fc > ffff8801d7ad0a00: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc > ================================================================== > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches