bisecting fixing commit since 14cfdbd39e316efd91ae6e403ef8211f0b022603 building syzkaller on 84f999d6319b21d9567132bf7ed26507f6d24310 testing commit 14cfdbd39e316efd91ae6e403ef8211f0b022603 with gcc (GCC) 8.1.0 kernel signature: 7e3b132e244f7535a220ac02569e27a14b6e2ad8ae7e6e5fef96621cefbe7193 all runs: crashed: kernel BUG at mm/hugetlb.c:LINE! testing current HEAD 3fc898571b974f9a05e4e5c1fe17b18548207091 testing commit 3fc898571b974f9a05e4e5c1fe17b18548207091 with gcc (GCC) 8.1.0 kernel signature: ceb3018e3356a6730d2f010d01f49540728325fdfcd95d904fe73cf44e584229 all runs: crashed: kernel BUG at mm/hugetlb.c:LINE! revisions tested: 2, total time: 23m34.271677573s (build: 17m10.860914085s, test: 5m55.220038108s) the crash still happens on HEAD commit msg: Linux 4.19.128 crash: kernel BUG at mm/hugetlb.c:LINE! batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! overlayfs: upper fs does not support xattr, falling back to index=off and metacopy=off. IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready batman_adv: batadv0: Interface activated: batadv_slave_1 ------------[ cut here ]------------ kernel BUG at mm/hugetlb.c:3371! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 invalid opcode: 0000 [#1] PREEMPT SMP KASAN batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! CPU: 1 PID: 7829 Comm: syz-executor.0 Not tainted 4.19.128-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__unmap_hugepage_range+0x7cc/0x980 mm/hugetlb.c:3371 Code: 75 7f 48 83 3d bc da 9b 06 00 74 22 4c 89 ff 48 89 da e8 f7 cc 9b ff 66 90 4c 89 e7 e8 ed aa 46 05 e9 82 fb ff ff 0f 0b 0f 0b <0f> 0b 0f 0b 0f 0b 48 89 cf e8 96 db 02 00 e9 d5 fb ff ff 48 89 df RSP: 0018:ffff88808fe3f708 EFLAGS: 00010206 RAX: 00000000001fffff RBX: 0000000020000000 RCX: 0000000000000009 RDX: 1ffffffff1432f58 RSI: ffff88808fc4a630 RDI: ffffffff8a197ac0 RBP: ffff88808fe3f870 R08: 0000000000000000 R09: fffffbfff14284e0 R10: fffffbfff14284e0 R11: 0000000000000001 R12: ffff88808dc309c0 R13: ffff88808fe3f848 R14: ffffffff8a197ab0 R15: ffff888090b933c0 FS: 00007fce7c5ee700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd0a7e2c000 CR3: 000000009c9be000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __unmap_hugepage_range_final+0xd/0x40 mm/hugetlb.c:3460 unmap_single_vma+0x1c1/0x300 mm/memory.c:1552 unmap_vmas+0xe7/0x1a0 mm/memory.c:1586 exit_mmap+0x251/0x450 mm/mmap.c:3091 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 __mmput kernel/fork.c:1015 [inline] mmput+0x107/0x3f0 kernel/fork.c:1036 exit_mm kernel/exit.c:546 [inline] do_exit+0x9c5/0x2dc0 kernel/exit.c:867 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! do_group_exit+0xf4/0x2f0 kernel/exit.c:983 get_signal+0x313/0x1a00 kernel/signal.c:2588 do_signal+0x87/0x1960 arch/x86/kernel/signal.c:821 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! exit_to_usermode_loop+0x114/0x200 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c849 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fce7c5edcf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 000000000076bfa8 RCX: 000000000045c849 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000076bfac RBP: 000000000076bfa0 R08: 000000000000000e R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 000000000076bfac R13: 00007ffe24c7fb3f R14: 00007fce7c5ee9c0 R15: 000000000076bfac Modules linked in: ---[ end trace 74e94669c96bffc1 ]--- IPv6: ADDRCONF(NETDEV_UP): batadv_slave_0: link is not ready RIP: 0010:__unmap_hugepage_range+0x7cc/0x980 mm/hugetlb.c:3371 batman_adv: batadv0: Interface activated: batadv_slave_0 Code: 75 7f 48 83 3d bc da 9b 06 00 74 22 4c 89 ff 48 89 da e8 f7 cc 9b ff 66 90 4c 89 e7 e8 ed aa 46 05 e9 82 fb ff ff 0f 0b 0f 0b <0f> 0b 0f 0b 0f 0b 48 89 cf e8 96 db 02 00 e9 d5 fb ff ff 48 89 df IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready RSP: 0018:ffff88808fe3f708 EFLAGS: 00010206 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 RAX: 00000000001fffff RBX: 0000000020000000 RCX: 0000000000000009 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! RDX: 1ffffffff1432f58 RSI: ffff88808fc4a630 RDI: ffffffff8a197ac0 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 RBP: ffff88808fe3f870 R08: 0000000000000000 R09: fffffbfff14284e0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! R10: fffffbfff14284e0 R11: 0000000000000001 R12: ffff88808dc309c0 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 R13: ffff88808fe3f848 R14: ffffffff8a197ab0 R15: ffff888090b933c0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! FS: 00007fce7c5ee700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd0a7e35000 CR3: 00000000944ef000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400