From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48857C4332F for ; Thu, 3 Nov 2022 02:35:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231154AbiKCCfs (ORCPT ); Wed, 2 Nov 2022 22:35:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35236 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230336AbiKCCfo (ORCPT ); Wed, 2 Nov 2022 22:35:44 -0400 Received: from mail-io1-f70.google.com (mail-io1-f70.google.com [209.85.166.70]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29C3313DC4 for ; Wed, 2 Nov 2022 19:35:43 -0700 (PDT) Received: by mail-io1-f70.google.com with SMTP id z15-20020a5e860f000000b006c09237cc06so257798ioj.21 for ; Wed, 02 Nov 2022 19:35:43 -0700 (PDT) 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v3-20020a92c6c3000000b0030096a09cd0mr16421159ilm.145.1667442942486; Wed, 02 Nov 2022 19:35:42 -0700 (PDT) Date: Wed, 02 Nov 2022 19:35:42 -0700 In-Reply-To: <000000000000cb639605ec7f6e10@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000452ed505ec87d0ad@google.com> Subject: Re: [syzbot] BUG: unable to handle kernel paging request in ovl_set_acl From: syzbot To: linux-kernel@vger.kernel.org, linux-unionfs@vger.kernel.org, miklos@szeredi.hu, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org syzbot has found a reproducer for the following issue on: HEAD commit: 61c3426aca2c Add linux-next specific files for 20221102 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=118e21de880000 kernel config: https://syzkaller.appspot.com/x/.config?x=acb529cc910d907c dashboard link: https://syzkaller.appspot.com/bug?extid=3f6ef1c4586bb6fd1f61 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1620a689880000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=153fb2a9880000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/cc56d88dd6a3/disk-61c3426a.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/5921b65b080f/vmlinux-61c3426a.xz kernel image: https://storage.googleapis.com/syzbot-assets/39cbd355fedd/bzImage-61c3426a.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+3f6ef1c4586bb6fd1f61@syzkaller.appspotmail.com BUG: unable to handle page fault for address: ffffffffffffffc3 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD bc8f067 P4D bc8f067 PUD bc91067 PMD 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 1 PID: 5240 Comm: syz-executor244 Not tainted 6.1.0-rc3-next-20221102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 RIP: 0010:arch_atomic_fetch_sub arch/x86/include/asm/atomic.h:190 [inline] RIP: 0010:atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:177 [inline] RIP: 0010:__refcount_sub_and_test include/linux/refcount.h:272 [inline] RIP: 0010:__refcount_dec_and_test include/linux/refcount.h:315 [inline] RIP: 0010:refcount_dec_and_test include/linux/refcount.h:333 [inline] RIP: 0010:posix_acl_release include/linux/posix_acl.h:57 [inline] RIP: 0010:posix_acl_release include/linux/posix_acl.h:55 [inline] RIP: 0010:ovl_set_or_remove_acl fs/overlayfs/inode.c:624 [inline] RIP: 0010:ovl_set_acl+0x730/0x910 fs/overlayfs/inode.c:685 Code: a3 24 ff 4c 89 ff 49 89 c4 e8 cc 2f 81 fe 4d 85 e4 74 7f e8 52 e9 ac fe be 04 00 00 00 4c 89 e7 bb ff ff ff ff e8 60 7a f9 fe 41 0f c1 1c 24 bf 01 00 00 00 89 de e8 fe e5 ac fe 83 fb 01 0f RSP: 0018:ffffc90003c0fad8 EFLAGS: 00010246 RAX: 0000000000000001 RBX: 00000000ffffffff RCX: ffffffff82cff810 RDX: fffffbfffffffff9 RSI: 0000000000000004 RDI: ffffffffffffffc3 RBP: ffff888078a5ca48 R08: 0000000000000001 R09: ffffffffffffffc6 R10: fffffbfffffffff8 R11: 0000000000000001 R12: ffffffffffffffc3 R13: ffff8880764ba330 R14: 1ffff92000781f60 R15: ffff888024e04f00 FS: 0000555555b7c300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffc3 CR3: 0000000026941000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: set_posix_acl+0x257/0x320 fs/posix_acl.c:957 vfs_remove_acl+0x272/0x630 fs/posix_acl.c:1209 removexattr+0x12a/0x1b0 fs/xattr.c:894 path_removexattr+0x174/0x1a0 fs/xattr.c:910 __do_sys_removexattr fs/xattr.c:924 [inline] __se_sys_removexattr fs/xattr.c:921 [inline] __x64_sys_removexattr+0x55/0x80 fs/xattr.c:921 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f653cc6fbf9 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffffec22658 EFLAGS: 00000246 ORIG_RAX: 00000000000000c5 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f653cc6fbf9 RDX: 00007f653cc6fbf9 RSI: 0000000020000040 RDI: 0000000020000000 RBP: 00007f653cc33da0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000280 R11: 0000000000000246 R12: 00007f653cc33e30 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: CR2: ffffffffffffffc3 ---[ end trace 0000000000000000 ]--- RIP: 0010:arch_atomic_fetch_sub arch/x86/include/asm/atomic.h:190 [inline] RIP: 0010:atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:177 [inline] RIP: 0010:__refcount_sub_and_test include/linux/refcount.h:272 [inline] RIP: 0010:__refcount_dec_and_test include/linux/refcount.h:315 [inline] RIP: 0010:refcount_dec_and_test include/linux/refcount.h:333 [inline] RIP: 0010:posix_acl_release include/linux/posix_acl.h:57 [inline] RIP: 0010:posix_acl_release include/linux/posix_acl.h:55 [inline] RIP: 0010:ovl_set_or_remove_acl fs/overlayfs/inode.c:624 [inline] RIP: 0010:ovl_set_acl+0x730/0x910 fs/overlayfs/inode.c:685 Code: a3 24 ff 4c 89 ff 49 89 c4 e8 cc 2f 81 fe 4d 85 e4 74 7f e8 52 e9 ac fe be 04 00 00 00 4c 89 e7 bb ff ff ff ff e8 60 7a f9 fe 41 0f c1 1c 24 bf 01 00 00 00 89 de e8 fe e5 ac fe 83 fb 01 0f RSP: 0018:ffffc90003c0fad8 EFLAGS: 00010246 RAX: 0000000000000001 RBX: 00000000ffffffff RCX: ffffffff82cff810 RDX: fffffbfffffffff9 RSI: 0000000000000004 RDI: ffffffffffffffc3 RBP: ffff888078a5ca48 R08: 0000000000000001 R09: ffffffffffffffc6 R10: fffffbfffffffff8 R11: 0000000000000001 R12: ffffffffffffffc3 R13: ffff8880764ba330 R14: 1ffff92000781f60 R15: ffff888024e04f00 FS: 0000555555b7c300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffc3 CR3: 0000000026941000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: a3 24 ff 4c 89 ff 49 movabs %eax,0xc48949ff894cff24 7: 89 c4 9: e8 cc 2f 81 fe callq 0xfe812fda e: 4d 85 e4 test %r12,%r12 11: 74 7f je 0x92 13: e8 52 e9 ac fe callq 0xfeace96a 18: be 04 00 00 00 mov $0x4,%esi 1d: 4c 89 e7 mov %r12,%rdi 20: bb ff ff ff ff mov $0xffffffff,%ebx 25: e8 60 7a f9 fe callq 0xfef97a8a * 2a: f0 41 0f c1 1c 24 lock xadd %ebx,(%r12) <-- trapping instruction 30: bf 01 00 00 00 mov $0x1,%edi 35: 89 de mov %ebx,%esi 37: e8 fe e5 ac fe callq 0xfeace63a 3c: 83 fb 01 cmp $0x1,%ebx 3f: 0f .byte 0xf