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 --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches
