Return-Path: Received: from fieldses.org ([173.255.197.46]:35914 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752944AbeDQVdJ (ORCPT ); Tue, 17 Apr 2018 17:33:09 -0400 Date: Tue, 17 Apr 2018 17:33:08 -0400 From: "J. Bruce Fields" To: syzbot Cc: anna.schumaker@netapp.com, davem@davemloft.net, jlayton@kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com, trond.myklebust@primarydata.com Subject: Re: general protection fault in encode_rpcb_string Message-ID: <20180417213308.GC18217@fieldses.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mon, Apr 16, 2018 at 09:02:01PM -0700, syzbot wrote: > syzbot hit the following crash on bpf-next commit > 5d1365940a68dd57b031b6e3c07d7d451cd69daf (Thu Apr 12 18:09:05 2018 +0000) > Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net > syzbot dashboard link: > https://syzkaller.appspot.com/bug?extid=4b98281f2401ab849f4b > > So far this crash happened 2 times on bpf-next. > C reproducer: https://syzkaller.appspot.com/x/repro.c?id=6433835633868800 > syzkaller reproducer: > https://syzkaller.appspot.com/x/repro.syz?id=6407311794896896 > Raw console output: > https://syzkaller.appspot.com/x/log.txt?id=5861511176126464 Based on that, looks like it's attempting an nfs mount while causing kmalloc failures? Probably one of rpcb->r_netid, r_addr, or r_owner was bad in rpcb_enc_getaddr. Hm, and previous log makes it look like it was an rpc_sockaddr2uaddr() in rpcb_getport_async() that was made to fail. Do we need to check for failure of: map->r_addr = rpc_sockaddr2uaddr(sap, GFP_ATOMIC); ? --b. > Kernel config: > https://syzkaller.appspot.com/x/.config?id=-5947642240294114534 > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+4b98281f2401ab849f4b@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. > > RBP: 00000000006dbc50 R08: 000000002000a000 R09: 0000000000003437 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe464ffed80 > R13: 0030656c69662f2e R14: ffffffffffffffff R15: 0000000000000006 > kasan: CONFIG_KASAN_INLINE enabled > kasan: GPF could be caused by NULL-ptr deref or user memory access > general protection fault: 0000 [#1] SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 0 PID: 1861 Comm: kworker/u4:4 Not tainted 4.16.0+ #2 > Hardware name: Google Google Compute Engine/Google Compute Engine, > BIOS Google 01/01/2011 > Workqueue: rpciod rpc_async_schedule > RIP: 0010:strlen+0x1f/0xa0 lib/string.c:479 > RSP: 0018:ffff8801cf75f318 EFLAGS: 00010296 > RAX: dffffc0000000000 RBX: ffff8801cf68f200 RCX: ffffffff86a8c407 > RDX: 0000000000000000 RSI: ffffffff86a84d7b RDI: 0000000000000000 > RBP: ffff8801cf75f330 R08: ffff8801cf7de080 R09: ffffed0039ea3d43 > R10: ffffed0039ea3d43 R11: ffff8801cf51ea1f R12: 0000000000000000 > R13: 0000000002000000 R14: 0000000000000000 R15: ffff8801cf75f3e0 > FS: 0000000000000000(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f64808a4000 CR3: 00000001b566a000 CR4: 00000000001406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > strlen include/linux/string.h:267 [inline] > encode_rpcb_string+0x23/0x70 net/sunrpc/rpcb_clnt.c:914 > rpcb_enc_getaddr+0x146/0x1f0 net/sunrpc/rpcb_clnt.c:940 > rpcauth_wrap_req_encode net/sunrpc/auth.c:777 [inline] > rpcauth_wrap_req+0x1a8/0x230 net/sunrpc/auth.c:791 > rpc_xdr_encode net/sunrpc/clnt.c:1754 [inline] > call_transmit+0x8a9/0xfe0 net/sunrpc/clnt.c:1949 > __rpc_execute+0x28a/0xfe0 net/sunrpc/sched.c:784 > rpc_async_schedule+0x16/0x20 net/sunrpc/sched.c:857 > process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145 > worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279 > kthread+0x345/0x410 kernel/kthread.c:238 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411 > Code: 37 ff ff ff 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff > df 55 48 89 fa 48 c1 ea 03 48 89 e5 41 54 49 89 fc 53 48 83 ec 08 > <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 4d 41 80 3c > RIP: strlen+0x1f/0xa0 lib/string.c:479 RSP: ffff8801cf75f318 > ---[ end trace bd76ed0378a56845 ]--- > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug > is merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title > If you want to test a patch for this bug, please reply with: > #syz test: git://repo/address.git branch > and provide the patch inline or as an attachment. > To mark this as a duplicate of another syzbot report, please reply with: > #syz dup: exact-subject-of-another-report > If it's a one-off invalid bug report, please reply with: > #syz invalid > Note: if the crash happens again, it will cause creation of a new > bug report. > Note: all commands must start from beginning of the line in the email body.