From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ua0-f199.google.com (mail-ua0-f199.google.com [209.85.217.199]) by kanga.kvack.org (Postfix) with ESMTP id 6B9466B0005 for ; Wed, 31 Jan 2018 05:16:03 -0500 (EST) Received: by mail-ua0-f199.google.com with SMTP id o42so9871933uao.12 for ; Wed, 31 Jan 2018 02:16:03 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id e6sor512126vkf.289.2018.01.31.02.16.02 for (Google Transport Security); Wed, 31 Jan 2018 02:16:02 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20180130213607.i4oybskvoxpzxqxd@gmail.com> References: <94eb2c05551289ffff0563224e41@google.com> <20180130213607.i4oybskvoxpzxqxd@gmail.com> From: Kees Cook Date: Wed, 31 Jan 2018 21:16:00 +1100 Message-ID: Subject: Re: WARNING in usercopy_warn Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Eric Biggers Cc: James Morse , keun-o.park@darkmatter.ae, syzbot , Laura Abbott , LKML , Linux-MM , Ingo Molnar , syzkaller-bugs@googlegroups.com On Wed, Jan 31, 2018 at 8:36 AM, Eric Biggers wrote: > On Fri, Jan 19, 2018 at 06:58:01AM -0800, syzbot wrote: >> Hello, >> >> syzbot hit the following crash on linux-next commit >> b625c1ff82272e26c76570d3c7123419ec345b20 >> >> So far this crash happened 5 times on linux-next, mmots. >> C reproducer is attached. >> syzkaller reproducer is attached. >> Raw console output is attached. >> compiler: gcc (GCC) 7.1.1 20170620 >> .config is attached. >> >> IMPORTANT: if you fix the bug, please add the following tag to the commit: >> Reported-by: syzbot+e2d6cfb305e9f3911dea@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. >> >> device syz0 entered promiscuous mode >> ------------[ cut here ]------------ >> Bad or missing usercopy whitelist? Kernel memory exposure attempt detected >> from SLAB object 'skbuff_head_cache' (offset 64, size 16)! >> WARNING: CPU: 0 PID: 3663 at mm/usercopy.c:81 usercopy_warn+0xdb/0x100 >> mm/usercopy.c:76 >> Kernel panic - not syncing: panic_on_warn set ... >> >> CPU: 0 PID: 3663 Comm: syzkaller694156 Not tainted 4.15.0-rc7-next-20180115+ >> #97 >> 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+0x194/0x257 lib/dump_stack.c:53 >> panic+0x1e4/0x41c kernel/panic.c:183 >> __warn+0x1dc/0x200 kernel/panic.c:547 >> report_bug+0x211/0x2d0 lib/bug.c:184 >> fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178 >> fixup_bug arch/x86/kernel/traps.c:247 [inline] >> do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 >> do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 >> invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:1085 >> RIP: 0010:usercopy_warn+0xdb/0x100 mm/usercopy.c:76 >> RSP: 0018:ffff8801d99df548 EFLAGS: 00010282 >> RAX: dffffc0000000008 RBX: ffffffff865cf19f RCX: ffffffff815aba6e >> RDX: 0000000000000000 RSI: 1ffff1003b33be2e RDI: 1ffff1003b33be64 >> RBP: ffff8801d99df5a0 R08: 0000000000000000 R09: 0000000000000000 >> R10: 00000000000003e6 R11: 0000000000000000 R12: ffffffff86200d00 >> R13: ffffffff85d2cfc0 R14: 0000000000000040 R15: 0000000000000010 >> __check_heap_object+0x89/0xc0 mm/slab.c:4426 >> check_heap_object mm/usercopy.c:236 [inline] >> __check_object_size+0x272/0x530 mm/usercopy.c:259 >> check_object_size include/linux/thread_info.h:112 [inline] >> check_copy_size include/linux/thread_info.h:143 [inline] >> copy_to_user include/linux/uaccess.h:154 [inline] >> put_cmsg+0x233/0x3f0 net/core/scm.c:242 >> sock_recv_errqueue+0x200/0x3e0 net/core/sock.c:2913 >> packet_recvmsg+0xb2e/0x17a0 net/packet/af_packet.c:3296 >> sock_recvmsg_nosec net/socket.c:803 [inline] >> sock_recvmsg+0xc9/0x110 net/socket.c:810 >> ___sys_recvmsg+0x2a4/0x640 net/socket.c:2179 >> __sys_recvmmsg+0x2a9/0xaf0 net/socket.c:2287 >> SYSC_recvmmsg net/socket.c:2368 [inline] >> SyS_recvmmsg+0xc4/0x160 net/socket.c:2352 >> entry_SYSCALL_64_fastpath+0x29/0xa0 >> RIP: 0033:0x444339 >> RSP: 002b:00007ffdb359d7d8 EFLAGS: 00000203 ORIG_RAX: 000000000000012b >> RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000444339 >> RDX: 0000000000000001 RSI: 0000000020ef7fc4 RDI: 0000000000000005 >> RBP: 00000000006ce018 R08: 0000000020000000 R09: 0000000000000001 >> R10: 0000000000002000 R11: 0000000000000203 R12: 0000000000402020 >> R13: 00000000004020b0 R14: 0000000000000000 R15: 0000000000000000 >> Dumping ftrace buffer: >> (ftrace buffer empty) >> Kernel Offset: disabled >> Rebooting in 86400 seconds.. > > Kees, has this been fixed yet? Hi! Thanks for the ping. I missed this in my backlog of email across LCA. I'm looking at it now... -Kees -- Kees Cook Pixel Security -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org