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From:   Dmitry Vyukov <dvyukov@google.com>
Date:   Fri, 29 Nov 2019 12:47:43 +0100
Message-ID: <CACT4Y+ZNAfkrE0M=eCHcmy2LhPG_kKbg4mOh54YN6Bgb4b3F5w@mail.gmail.com>
Subject: Re: [PATCH v11 1/4] kasan: support backing vmalloc space with real
 shadow memory
To:     Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc:     Daniel Axtens <dja@axtens.net>, Qian Cai <cai@lca.pw>,
        kasan-dev <kasan-dev@googlegroups.com>,
        Linux-MM <linux-mm@kvack.org>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        Alexander Potapenko <glider@google.com>,
        Andy Lutomirski <luto@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Christophe Leroy <christophe.leroy@c-s.fr>,
        linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
        Vasily Gorbik <gor@linux.ibm.com>
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Sender: linux-kernel-owner@vger.kernel.org
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On Fri, Nov 29, 2019 at 12:38 PM Andrey Ryabinin
<aryabinin@virtuozzo.com> wrote:
> >>>
> >>>
> >>> Not sure if it's the same or not. Is it addressed by something in flight?
> >>>
> >>> My config:
> >>> https://gist.githubusercontent.com/dvyukov/36c7be311fdec9cd51c649f7c3cb2ddb/raw/39c6f864fdd0ffc53f0822b14c354a73c1695fa1/gistfile1.txt
> >>
> >>
> >> I've tried this fix for pcpu_get_vm_areas:
> >> https://groups.google.com/d/msg/kasan-dev/t_F2X1MWKwk/h152Z3q2AgAJ
> >> and it helps. But this will break syzbot on linux-next soon.
> >
> >
> > Can this be related as well?
> > Crashes on accesses to shadow on the ion memory...
>
> Nope, it's vm_map_ram() not being handled


Another suspicious one. Related to kasan/vmalloc?

BUG: unable to handle page fault for address: fffff52005b80000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 7ffcd067 P4D 7ffcd067 PUD 2cd10067 PMD 66d76067 PTE 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 2 PID: 9211 Comm: syz-executor.2 Not tainted 5.4.0-next-20191129+ #6
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
RIP: 0010:xfs_sb_read_verify+0xe9/0x540 fs/xfs/libxfs/xfs_sb.c:691
Code: fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 1e 04 00 00 4d 8b ac 24
30 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <0f> b6
04 02 84 c0 74 08 3c 03 0f 8e ad 03 00 00 41 8b 45 00 bf 58
RSP: 0018:ffffc9000a58f8d0 EFLAGS: 00010a06
RAX: dffffc0000000000 RBX: 1ffff920014b1f1d RCX: ffffc9000af42000
RDX: 1ffff92005b80000 RSI: ffffffff82914404 RDI: ffff88805cdb1460
RBP: ffffc9000a58fab0 R08: ffff8880610cd380 R09: ffffed1005a87045
R10: ffffed1005a87044 R11: ffff88802d438223 R12: ffff88805cdb1340
R13: ffffc9002dc00000 R14: ffffc9000a58fa88 R15: ffff888061b5c000
FS:  00007fb49bda9700(0000) GS:ffff88802d400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffff52005b80000 CR3: 0000000060769006 CR4: 0000000000760ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 xfs_buf_ioend+0x228/0xdc0 fs/xfs/xfs_buf.c:1162
 __xfs_buf_submit+0x38b/0xe50 fs/xfs/xfs_buf.c:1485
 xfs_buf_submit fs/xfs/xfs_buf.h:268 [inline]
 xfs_buf_read_uncached+0x15c/0x560 fs/xfs/xfs_buf.c:897
 xfs_readsb+0x2d0/0x540 fs/xfs/xfs_mount.c:298
 xfs_fc_fill_super+0x3e6/0x11f0 fs/xfs/xfs_super.c:1415
 get_tree_bdev+0x444/0x620 fs/super.c:1340
 xfs_fc_get_tree+0x1c/0x20 fs/xfs/xfs_super.c:1550
 vfs_get_tree+0x8e/0x300 fs/super.c:1545
 do_new_mount fs/namespace.c:2822 [inline]
 do_mount+0x152d/0x1b50 fs/namespace.c:3142
 ksys_mount+0x114/0x130 fs/namespace.c:3351
 __do_sys_mount fs/namespace.c:3365 [inline]
 __se_sys_mount fs/namespace.c:3362 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3362
 do_syscall_64+0xfa/0x780 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x46736a
Code: 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d
01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb49bda8a78 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fb49bda8af0 RCX: 000000000046736a
RDX: 00007fb49bda8ad0 RSI: 0000000020000140 RDI: 00007fb49bda8af0
RBP: 00007fb49bda8ad0 R08: 00007fb49bda8b30 R09: 00007fb49bda8ad0
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fb49bda8b30
R13: 00000000004b1c60 R14: 00000000004b006d R15: 00007fb49bda96bc
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)
CR2: fffff52005b80000
---[ end trace eddd8949d4c898df ]---
RIP: 0010:xfs_sb_read_verify+0xe9/0x540 fs/xfs/libxfs/xfs_sb.c:691
Code: fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 1e 04 00 00 4d 8b ac 24
30 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <0f> b6
04 02 84 c0 74 08 3c 03 0f 8e ad 03 00 00 41 8b 45 00 bf 58
RSP: 0018:ffffc9000a58f8d0 EFLAGS: 00010a06
RAX: dffffc0000000000 RBX: 1ffff920014b1f1d RCX: ffffc9000af42000
RDX: 1ffff92005b80000 RSI: ffffffff82914404 RDI: ffff88805cdb1460
RBP: ffffc9000a58fab0 R08: ffff8880610cd380 R09: ffffed1005a87045
R10: ffffed1005a87044 R11: ffff88802d438223 R12: ffff88805cdb1340
R13: ffffc9002dc00000 R14: ffffc9000a58fa88 R15: ffff888061b5c000
FS:  00007fb49bda9700(0000) GS:ffff88802d400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffff52005b80000 CR3: 0000000060769006 CR4: 0000000000760ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554