From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752602AbeDLKCD (ORCPT ); Thu, 12 Apr 2018 06:02:03 -0400 Received: from mail-it0-f70.google.com ([209.85.214.70]:43156 "EHLO mail-it0-f70.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751747AbeDLKCB (ORCPT ); Thu, 12 Apr 2018 06:02:01 -0400 X-Google-Smtp-Source: AIpwx4+dLQofnrZ8Nr0jW4C9i7MEGYuWU1f0aOUCI5L63U1Fe/fLpygpmeyXfABvGM0+g7fZN4uxfoCyZdQd/HLMgwRPMyAXQKkS MIME-Version: 1.0 Date: Thu, 12 Apr 2018 03:02:01 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <001a1140f656c722960569a3d857@google.com> Subject: KASAN: slab-out-of-bounds Write in perf_callchain_user From: syzbot To: acme@kernel.org, alexander.shishkin@linux.intel.com, hpa@zytor.com, jolsa@redhat.com, linux-kernel@vger.kernel.org, mingo@redhat.com, namhyung@kernel.org, peterz@infradead.org, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, x86@kernel.org Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot hit the following crash on bpf-next commit 17dec0a949153d9ac00760ba2f5b78cb583e995f (Wed Apr 4 02:15:32 2018 +0000) Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace syzbot dashboard link: https://syzkaller.appspot.com/bug?extid=7c449856228b63ac951e So far this crash happened 2 times on bpf-next. syzkaller reproducer: https://syzkaller.appspot.com/x/repro.syz?id=4514433808203776 Raw console output: https://syzkaller.appspot.com/x/log.txt?id=5570436679073792 Kernel config: https://syzkaller.appspot.com/x/.config?id=-2735707888269579554 compiler: gcc (GCC) 8.0.1 20180301 (experimental) IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+7c449856228b63ac951e@syzkaller.appspotmail.com It will help syzbot understand when the bug is fixed. See footer for details. If you forward the report, please keep this part and the footer. IPVS: ftp: loaded support on port[0] = 21 ================================================================== BUG: KASAN: slab-out-of-bounds in perf_callchain_store include/linux/perf_event.h:1147 [inline] BUG: KASAN: slab-out-of-bounds in perf_callchain_user+0xe31/0xfe0 arch/x86/events/core.c:2485 Write of size 8 at addr ffff8801d87f2d40 by task udevd/2377 CPU: 0 PID: 2377 Comm: udevd Not tainted 4.16.0+ #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b9/0x29f lib/dump_stack.c:53 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0xac/0x2f5 mm/kasan/report.c:412 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report.c:438 perf_callchain_store include/linux/perf_event.h:1147 [inline] perf_callchain_user+0xe31/0xfe0 arch/x86/events/core.c:2485 get_perf_callchain+0x798/0xb20 kernel/events/callchain.c:227 perf_callchain kernel/events/core.c:6354 [inline] perf_prepare_sample+0x123d/0x1900 kernel/events/core.c:6380 __perf_event_output kernel/events/core.c:6494 [inline] perf_event_output_forward+0x10a/0x2b0 kernel/events/core.c:6512 __perf_event_overflow+0x231/0x4b0 kernel/events/core.c:7748 perf_swevent_overflow+0xad/0x150 kernel/events/core.c:7824 perf_swevent_event+0x1f0/0x2e0 kernel/events/core.c:7857 perf_tp_event+0x4da/0xc30 kernel/events/core.c:8280 perf_trace_run_bpf_submit+0x23f/0x370 kernel/events/core.c:8254 perf_trace_lock_acquire+0x4f1/0x980 include/trace/events/lock.h:13 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x38e/0x520 kernel/locking/lockdep.c:3919 finish_lock_switch kernel/sched/core.c:2602 [inline] finish_task_switch+0x1c2/0x820 kernel/sched/core.c:2701 context_switch kernel/sched/core.c:2851 [inline] __schedule+0x80f/0x1e40 kernel/sched/core.c:3490 schedule+0xef/0x430 kernel/sched/core.c:3549 schedule_hrtimeout_range_clock+0x3c0/0x470 kernel/time/hrtimer.c:1883 schedule_hrtimeout_range+0x2a/0x40 kernel/time/hrtimer.c:1940 ep_poll+0xf2e/0x11d0 fs/eventpoll.c:1812 do_epoll_wait+0x1b0/0x200 fs/eventpoll.c:2191 SYSC_epoll_wait fs/eventpoll.c:2201 [inline] SyS_epoll_wait+0x2c/0x40 fs/eventpoll.c:2198 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7fe39adf3943 RSP: 002b:00007ffc13750708 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007fe39adf3943 RDX: 0000000000000008 RSI: 00007ffc13750800 RDI: 000000000000000a RBP: 0000000001b676c0 R08: 0000000000000000 R09: 00007fe39ae3ca60 R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000a56 R13: 0000000000000000 R14: 0000000001b674a0 R15: 0000000001b4e250 Allocated by task 4544: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:552 __do_kmalloc_node mm/slab.c:3670 [inline] __kmalloc_node+0x47/0x70 mm/slab.c:3677 kmalloc_node include/linux/slab.h:554 [inline] alloc_callchain_buffers kernel/events/callchain.c:91 [inline] get_callchain_buffers+0x31a/0x4b0 kernel/events/callchain.c:138 perf_event_alloc.part.91+0x2274/0x30a0 kernel/events/core.c:10047 perf_event_alloc kernel/events/core.c:10376 [inline] SYSC_perf_event_open+0xa8a/0x2fa0 kernel/events/core.c:10477 SyS_perf_event_open+0x35/0x40 kernel/events/core.c:10366 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff8801d87f1c40 which belongs to the cache kmalloc-8192 of size 8192 The buggy address is located 4352 bytes inside of 8192-byte region [ffff8801d87f1c40, ffff8801d87f3c40) The buggy address belongs to the page: page:ffffea000761fc00 count:1 mapcount:0 mapping:ffff8801d87f1c40 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffff8801d87f1c40 0000000000000000 0000000100000001 raw: ffffea0007612020 ffffea0006b0ff20 ffff8801dac02080 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d87f2c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801d87f2c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ffff8801d87f2d00: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ^ ffff8801d87f2d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801d87f2e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== --- This bug is generated by a dumb bot. 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