Hello, syzbot found the following issue on: HEAD commit: c6b11acc Add linux-next specific files for 20201130 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=114b94e9500000 kernel config: https://syzkaller.appspot.com/x/.config?x=b5e03844e9b34d37 dashboard link: https://syzkaller.appspot.com/bug?extid=a59e7ceb87a83c5233df compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=150fed8b500000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1726291d500000 The issue was bisected to: commit 76761ffa9ea1ddca78e817bf7eec5fcb0378a00c Author: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> Date: Sun Nov 29 23:58:06 2020 +0000 mm/memcg: bail out early when !memcg in mem_cgroup_lruvec bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=122ff445500000 final oops: https://syzkaller.appspot.com/x/report.txt?x=112ff445500000 console output: https://syzkaller.appspot.com/x/log.txt?x=162ff445500000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+a59e7ceb87a83c5233df@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 76761ffa9ea1 ("mm/memcg: bail out early when !memcg in mem_cgroup_lruvec") BUG: unable to handle page fault for address: ffffffff81417c79 #PF: supervisor write access in kernel mode #PF: error_code(0x0003) - permissions violation PGD b08f067 P4D b08f067 PUD b090063 PMD 14001e1 Oops: 0003 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8503 Comm: syz-executor118 Not tainted 5.10.0-rc5-next-20201130-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mem_cgroup_lruvec include/linux/memcontrol.h:630 [inline] RIP: 0010:parent_lruvec include/linux/memcontrol.h:1560 [inline] RIP: 0010:workingset_age_nonresident+0x179/0x1c0 mm/workingset.c:242 Code: 85 db 0f 85 c8 fe ff ff 5b 5d 41 5c 41 5d 41 5e 41 5f e9 6a 67 cf ff e8 65 67 cf ff 49 8d 9d 18 4d 00 00 eb b3 e8 57 67 cf ff <4c> 89 ab c0 00 00 00 eb c7 e8 69 35 12 00 e9 d3 fe ff ff e8 5f 35 RSP: 0018:ffffc9000112f4c0 EFLAGS: 00010093 RAX: 0000000000000000 RBX: ffffffff81417bb9 RCX: 0000000000000000 RDX: ffff88801eee5040 RSI: ffffffff81a159f9 RDI: ffffffff81417c79 RBP: dffffc0000000000 R08: 0000000000000001 R09: ffff88813ffffdbf R10: ffffed1027ffffb7 R11: 0000000000000000 R12: ffffffff8e7911d0 R13: ffff88813fffb000 R14: 0000000000000001 R15: ffffffff8e7910b0 FS: 0000000002581880(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffff81417c79 CR3: 0000000013a2f000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: workingset_eviction+0x452/0x9b0 mm/workingset.c:266 __remove_mapping+0x867/0xd20 mm/vmscan.c:927 shrink_page_list+0x246a/0x5e80 mm/vmscan.c:1431 reclaim_pages+0x3e2/0xcd0 mm/vmscan.c:2148 madvise_cold_or_pageout_pte_range+0x1615/0x2880 mm/madvise.c:473 walk_pmd_range mm/pagewalk.c:89 [inline] walk_pud_range mm/pagewalk.c:160 [inline] walk_p4d_range mm/pagewalk.c:193 [inline] walk_pgd_range mm/pagewalk.c:229 [inline] __walk_page_range+0xda4/0x1e20 mm/pagewalk.c:331 walk_page_range+0x1be/0x450 mm/pagewalk.c:427 madvise_pageout_page_range mm/madvise.c:526 [inline] madvise_pageout+0x21b/0x390 mm/madvise.c:562 madvise_vma mm/madvise.c:943 [inline] do_madvise.part.0+0x9f2/0x1ed0 mm/madvise.c:1142 do_madvise mm/madvise.c:1168 [inline] __do_sys_madvise mm/madvise.c:1168 [inline] __se_sys_madvise mm/madvise.c:1166 [inline] __x64_sys_madvise+0x113/0x150 mm/madvise.c:1166 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x440279 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffe7c1ab298 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440279 RDX: 0000000000000015 RSI: 0000000000600003 RDI: 0000000020000000 RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000401a80 R13: 0000000000401b10 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: CR2: ffffffff81417c79 ---[ end trace 89bcebda47215cf6 ]--- RIP: 0010:mem_cgroup_lruvec include/linux/memcontrol.h:630 [inline] RIP: 0010:parent_lruvec include/linux/memcontrol.h:1560 [inline] RIP: 0010:workingset_age_nonresident+0x179/0x1c0 mm/workingset.c:242 Code: 85 db 0f 85 c8 fe ff ff 5b 5d 41 5c 41 5d 41 5e 41 5f e9 6a 67 cf ff e8 65 67 cf ff 49 8d 9d 18 4d 00 00 eb b3 e8 57 67 cf ff <4c> 89 ab c0 00 00 00 eb c7 e8 69 35 12 00 e9 d3 fe ff ff e8 5f 35 RSP: 0018:ffffc9000112f4c0 EFLAGS: 00010093 RAX: 0000000000000000 RBX: ffffffff81417bb9 RCX: 0000000000000000 RDX: ffff88801eee5040 RSI: ffffffff81a159f9 RDI: ffffffff81417c79 RBP: dffffc0000000000 R08: 0000000000000001 R09: ffff88813ffffdbf R10: ffffed1027ffffb7 R11: 0000000000000000 R12: ffffffff8e7911d0 R13: ffff88813fffb000 R14: 0000000000000001 R15: ffffffff8e7910b0 FS: 0000000002581880(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffff81417c79 CR3: 0000000013a2f000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 --- This report 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 issue. 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 issue, for details see: https://goo.gl/tpsmEJ#testing-patches