bisecting fixing commit since 14cfdbd39e316efd91ae6e403ef8211f0b022603 building syzkaller on 84f999d6319b21d9567132bf7ed26507f6d24310 testing commit 14cfdbd39e316efd91ae6e403ef8211f0b022603 with gcc (GCC) 8.1.0 kernel signature: b1b9ac6688e3727fe89a3128ef7552e6cc8c2721a4ec78e846d7a55de19d55f0 all runs: crashed: kernel BUG at mm/hugetlb.c:LINE! testing current HEAD 17a87580a8856170d59aab302226811a4ae69149 testing commit 17a87580a8856170d59aab302226811a4ae69149 with gcc (GCC) 8.1.0 kernel signature: 884d9d6b3e8667c91afd1473139a65da6063ca0214193d1ae050780b98904ff0 all runs: crashed: kernel BUG at mm/hugetlb.c:LINE! revisions tested: 2, total time: 26m2.825406898s (build: 19m2.678474457s, test: 6m4.786767385s) the crash still happens on HEAD commit msg: Linux 4.19.133 crash: kernel BUG at mm/hugetlb.c:LINE! overlayfs: upper fs does not support tmpfile. overlayfs: upper fs does not support xattr, falling back to index=off and metacopy=off. device veth1_macvtap entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): veth0_macvtap: link is not ready ------------[ cut here ]------------ kernel BUG at mm/hugetlb.c:3371! device veth1_macvtap entered promiscuous mode invalid opcode: 0000 [#1] PREEMPT SMP KASAN IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready CPU: 0 PID: 7832 Comm: syz-executor.0 Not tainted 4.19.133-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 IPv6: ADDRCONF(NETDEV_UP): veth1_to_batadv: link is not ready RIP: 0010:__unmap_hugepage_range+0x7cc/0x980 mm/hugetlb.c:3371 Code: 75 7f 48 83 3d 0c 5e 9b 06 00 74 22 4c 89 ff 48 89 da e8 17 60 9b ff 66 90 4c 89 e7 e8 1d ed 48 05 e9 82 fb ff ff 0f 0b 0f 0b <0f> 0b 0f 0b 0f 0b 48 89 cf e8 e6 db 02 00 e9 d5 fb ff ff 48 89 df RSP: 0018:ffff88808fae7708 EFLAGS: 00010206 RAX: 00000000001fffff RBX: 0000000020000000 RCX: 0000000000000009 RDX: 1ffffffff1433558 RSI: ffff888090f27250 RDI: ffffffff8a19aac0 RBP: ffff88808fae7870 R08: 0000000000000000 R09: fffffbfff1428ae0 R10: fffffbfff1428ae0 R11: 0000000000000001 R12: ffff88808e5b7000 R13: ffff88808fae7848 R14: ffffffff8a19aab0 R15: ffff888090134680 FS: 00007f69932e7700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000080 CR3: 000000009cf3d000 CR4: 00000000001406f0 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 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 exit_mmap+0x251/0x450 mm/mmap.c:3091 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! __mmput kernel/fork.c:1015 [inline] mmput+0x107/0x3f0 kernel/fork.c:1036 exit_mm kernel/exit.c:546 [inline] do_exit+0x9cd/0x2dc0 kernel/exit.c:874 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 do_group_exit+0xf4/0x2f0 kernel/exit.c:990 get_signal+0x313/0x1a30 kernel/signal.c:2588 do_signal+0x87/0x1960 arch/x86/kernel/signal.c:821 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 IPv6: ADDRCONF(NETDEV_UP): batadv_slave_0: link is not ready RIP: 0033:0x45c8c9 Code: 2d 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 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f69932e6cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 000000000076bfa8 RCX: 000000000045c8c9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000076bfac RBP: 000000000076bfa0 R08: 000000000000000e R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 000000000076bfac R13: 00007ffeef2c6fff R14: 00007f69932e79c0 R15: 000000000076bfac Modules linked in: ---[ end trace 45f1336686f39d6b ]--- batman_adv: batadv0: Interface activated: batadv_slave_0 RIP: 0010:__unmap_hugepage_range+0x7cc/0x980 mm/hugetlb.c:3371 IPv6: ADDRCONF(NETDEV_UP): veth1_macvtap: link is not ready Code: 75 7f 48 83 3d 0c 5e 9b 06 00 74 22 4c 89 ff 48 89 da e8 17 60 9b ff 66 90 4c 89 e7 e8 1d ed 48 05 e9 82 fb ff ff 0f 0b 0f 0b <0f> 0b 0f 0b 0f 0b 48 89 cf e8 e6 db 02 00 e9 d5 fb ff ff 48 89 df batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 RSP: 0018:ffff88808fae7708 EFLAGS: 00010206 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! RAX: 00000000001fffff RBX: 0000000020000000 RCX: 0000000000000009 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 RDX: 1ffffffff1433558 RSI: ffff888090f27250 RDI: ffffffff8a19aac0 RBP: ffff88808fae7870 R08: 0000000000000000 R09: fffffbfff1428ae0 R10: fffffbfff1428ae0 R11: 0000000000000001 R12: ffff88808e5b7000 R13: ffff88808fae7848 R14: ffffffff8a19aab0 R15: ffff888090134680 FS: 00007f69932e7700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9ae2586000 CR3: 00000000898c3000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400