Re: BUG: unable to handle kernel paging request in get_pfnblock_flags_mask

[Peter Xu]

On Tue, Apr 07, 2020 at 02:48:12PM -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following crash on:
> 
> HEAD commit:    bef7b2a7 Merge tag 'devicetree-for-5.7' of git://git.kerne..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1685901be00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=91b674b8f0368e69
> dashboard link: https://syzkaller.appspot.com/bug?extid=18638e81a805a2d96682
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11379efbe00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10172c5de00000
> 
> The bug was bisected to:
> 
> commit 4426e945df588f2878affddf88a51259200f7e29
> Author: Peter Xu <peterx@xxxxxxxxxx>
> Date:   Thu Apr 2 04:08:49 2020 +0000
> 
>     mm/gup: allow VM_FAULT_RETRY for multiple times
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16122ac7e00000
> final crash:    https://syzkaller.appspot.com/x/report.txt?x=15122ac7e00000
> console output: https://syzkaller.appspot.com/x/log.txt?x=11122ac7e00000
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+18638e81a805a2d96682@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 4426e945df58 ("mm/gup: allow VM_FAULT_RETRY for multiple times")
> 
> BUG: unable to handle page fault for address: fffff11043f9c809
> #PF: supervisor read access in kernel mode
> #PF: error_code(0x0000) - not-present page
> PGD 0 P4D 0 
> Oops: 0000 [#1] PREEMPT SMP KASAN
> CPU: 0 PID: 7170 Comm: syz-executor720 Not tainted 5.6.0-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> RIP: 0010:__nr_to_section include/linux/mmzone.h:1256 [inline]
> RIP: 0010:__pfn_to_section include/linux/mmzone.h:1335 [inline]
> RIP: 0010:get_pageblock_bitmap mm/page_alloc.c:452 [inline]
> RIP: 0010:__get_pfnblock_flags_mask mm/page_alloc.c:487 [inline]
> RIP: 0010:get_pfnblock_flags_mask+0x5b/0x190 mm/page_alloc.c:501
> Code: 0d ea e0 be 0a 48 85 c9 0f 84 aa 00 00 00 48 89 f7 48 c1 ef 16 48 8d 2c f9 48 b9 00 00 00 00 00 fc ff df 49 89 e8 49 c1 e8 03 <41> 80 3c 08 00 0f 85 87 00 00 00 48 8b 7d 00 48 85 ff 74 7a 83 e3
> RSP: 0000:ffffc90001697d40 EFLAGS: 00010a06
> RAX: 0000000000000007 RBX: 0001fffffcf404f2 RCX: dffffc0000000000
> RDX: 0000000000000002 RSI: fffffe7a02793d05 RDI: 000003fffff9e809
> RBP: ffffa8821fce4048 R08: 1ffff51043f9c809 R09: ffffed1013c9e829
> R10: ffff88809e4f4147 R11: ffffed1013c9e828 R12: ffff88809e4f4140
> R13: ffff88809e4f4148 R14: 0000000000000000 R15: ffff88809e4f4140
> FS:  000000000268a940(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: fffff11043f9c809 CR3: 000000009f94c000 CR4: 00000000001406f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  __dump_page+0x122/0x1a40 mm/debug.c:57
>  put_page_testzero include/linux/mm.h:675 [inline]
>  put_page include/linux/mm.h:1136 [inline]
>  lookup_node mm/mempolicy.c:907 [inline]
>  do_get_mempolicy mm/mempolicy.c:970 [inline]
>  kernel_get_mempolicy+0xe3f/0xfb0 mm/mempolicy.c:1615
>  __do_sys_get_mempolicy mm/mempolicy.c:1633 [inline]
>  __se_sys_get_mempolicy mm/mempolicy.c:1629 [inline]
>  __x64_sys_get_mempolicy+0xba/0x150 mm/mempolicy.c:1629
>  do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
>  entry_SYSCALL_64_after_hwframe+0x49/0xb3
> RIP: 0033:0x441789
> Code: e8 ac e8 ff ff 48 83 c4 18 c3 0f 1f 80 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 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007ffe6d5ec848 EFLAGS: 00000246 ORIG_RAX: 00000000000000ef
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441789
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 0000000000021c9b R08: 0000000000000003 R09: 0000000000402590
> R10: 000000002073b000 R11: 0000000000000246 R12: 0000000000402500
> R13: 0000000000402590 R14: 0000000000000000 R15: 0000000000000000
> Modules linked in:
> CR2: fffff11043f9c809
> ---[ end trace bdfbd15c6d2a525e ]---
> RIP: 0010:__nr_to_section include/linux/mmzone.h:1256 [inline]
> RIP: 0010:__pfn_to_section include/linux/mmzone.h:1335 [inline]
> RIP: 0010:get_pageblock_bitmap mm/page_alloc.c:452 [inline]
> RIP: 0010:__get_pfnblock_flags_mask mm/page_alloc.c:487 [inline]
> RIP: 0010:get_pfnblock_flags_mask+0x5b/0x190 mm/page_alloc.c:501
> Code: 0d ea e0 be 0a 48 85 c9 0f 84 aa 00 00 00 48 89 f7 48 c1 ef 16 48 8d 2c f9 48 b9 00 00 00 00 00 fc ff df 49 89 e8 49 c1 e8 03 <41> 80 3c 08 00 0f 85 87 00 00 00 48 8b 7d 00 48 85 ff 74 7a 83 e3
> RSP: 0000:ffffc90001697d40 EFLAGS: 00010a06
> RAX: 0000000000000007 RBX: 0001fffffcf404f2 RCX: dffffc0000000000
> RDX: 0000000000000002 RSI: fffffe7a02793d05 RDI: 000003fffff9e809
> RBP: ffffa8821fce4048 R08: 1ffff51043f9c809 R09: ffffed1013c9e829
> R10: ffff88809e4f4147 R11: ffffed1013c9e828 R12: ffff88809e4f4140
> R13: ffff88809e4f4148 R14: 0000000000000000 R15: ffff88809e4f4140
> FS:  000000000268a940(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: fffff11043f9c809 CR3: 000000009f94c000 CR4: 00000000001406f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Thanks; I think this is a dup of previous one too:

https://lore.kernel.org/lkml/0000000000002b25f105a2a3434d@xxxxxxxxxx/

#syz dup: BUG: unable to handle kernel paging request in kernel_get_mempolicy

-- 
Peter Xu