skbuff: skb_over_panic: text:ffffffff83b2a22f len:76 put:20 head:ffff8881daca6400 data:ffff8881daca6440 tail:0x8c end:0x80 dev:ip6gretap0 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:109! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 14456 Comm: syz-executor.0 Not tainted 5.4.197-syzkaller-00015-gf0306959ab7c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 RIP: 0010:skb_panic+0x14a/0x150 net/core/skbuff.c:105 Code: f2 ee 84 48 8b 74 24 08 48 8b 54 24 10 8b 0c 24 44 8b 44 24 04 49 89 e9 31 c0 53 41 55 41 54 41 57 e8 bf 62 c5 00 48 83 c4 20 <0f> 0b 0f 1f 40 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 68 4d 89 RSP: 0018:ffff8881f6e09b28 EFLAGS: 00010286 RAX: 0000000000000089 RBX: ffff8881ee094000 RCX: 9c25f7419b9a6400 RDX: 0000000000000503 RSI: 0000000000000503 RDI: 0000000000000000 RBP: ffff8881daca6400 R08: ffffffff814a983a R09: ffffed103edcaa08 R10: ffffed103edcaa08 R11: 1ffff1103edcaa07 R12: 000000000000008c R13: 0000000000000080 R14: dffffc0000000000 R15: ffff8881daca6440 FS: 00007f89a3ba2700(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000207a2000 CR3: 00000001e12ae000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: skb_over_panic net/core/skbuff.c:114 [inline] skb_put+0x148/0x1f0 net/core/skbuff.c:1877 add_grhead net/ipv6/mcast.c:1714 [inline] add_grec+0xe4f/0x1350 net/ipv6/mcast.c:1841 mld_send_cr net/ipv6/mcast.c:1967 [inline] mld_ifc_timer_expire+0x723/0xb30 net/ipv6/mcast.c:2474 call_timer_fn+0x31/0x350 kernel/time/timer.c:1418 expire_timers+0x21e/0x400 kernel/time/timer.c:1463 __run_timers+0x5b0/0x6b0 kernel/time/timer.c:1787 run_timer_softirq+0x46/0x80 kernel/time/timer.c:1800 __do_softirq+0x23e/0x643 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x195/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:538 [inline] smp_apic_timer_interrupt+0x113/0x440 arch/x86/kernel/apic/apic.c:1150 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:831 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:write_comp_data kernel/kcov.c:207 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x4/0x90 kernel/kcov.c:281 Code: 04 39 05 00 00 00 48 89 d7 48 83 cf 10 48 89 04 39 48 83 ca 18 4c 89 14 11 4c 89 44 f1 20 49 ff c1 4c 89 09 c3 90 4c 8b 04 24 <65> 48 8b 14 25 80 8d 02 00 65 8b 0d c8 34 a2 7e f7 c1 00 01 1f 00 RSP: 0018:ffff8881edcb7928 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffea0007b128c0 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: ffff8881edcb7b90 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8881edcb7a50 R08: ffffffff81851f61 R09: ffffed103c7ec001 R10: ffffed103c7ec001 R11: 1ffff1103c7ec000 R12: ffffea0007b128c8 R13: ffff8881e6fb49f0 R14: dead000000000100 R15: 1ffffd4000f62519 compound_head include/linux/page-flags.h:176 [inline] PageAnon include/linux/page-flags.h:463 [inline] zap_pte_range+0x561/0x1c10 mm/memory.c:1094 zap_pmd_range mm/memory.c:1221 [inline] zap_pud_range mm/memory.c:1250 [inline] zap_p4d_range mm/memory.c:1271 [inline] unmap_page_range+0x35e/0x450 mm/memory.c:1292 unmap_single_vma mm/memory.c:1337 [inline] unmap_vmas+0x306/0x440 mm/memory.c:1369 exit_mmap+0x286/0x4f0 mm/mmap.c:3166 __mmput+0x34/0x240 kernel/fork.c:1090 exit_mm kernel/exit.c:489 [inline] do_exit+0xb40/0x2b40 kernel/exit.c:799 do_group_exit+0x136/0x300 kernel/exit.c:910 get_signal+0xd99/0x13f0 kernel/signal.c:2735 do_signal+0x3b/0x540 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0xdd/0x1d0 arch/x86/entry/common.c:159 prepare_exit_to_usermode+0x17c/0x1d0 arch/x86/entry/common.c:194 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f89a4a2c279 Code: Bad RIP value. RSP: 002b:00007f89a3ba2218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f89a4b3ef88 RCX: 00007f89a4a2c279 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f89a4b3ef88 RBP: 00007f89a4b3ef80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f89a4b3ef8c R13: 00007ffeba1b008f R14: 00007f89a3ba2300 R15: 0000000000022000 Modules linked in: ---[ end trace ad7ad88396d1d0ed ]--- RIP: 0010:skb_panic+0x14a/0x150 net/core/skbuff.c:105 Code: f2 ee 84 48 8b 74 24 08 48 8b 54 24 10 8b 0c 24 44 8b 44 24 04 49 89 e9 31 c0 53 41 55 41 54 41 57 e8 bf 62 c5 00 48 83 c4 20 <0f> 0b 0f 1f 40 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 68 4d 89 RSP: 0018:ffff8881f6e09b28 EFLAGS: 00010286 RAX: 0000000000000089 RBX: ffff8881ee094000 RCX: 9c25f7419b9a6400 RDX: 0000000000000503 RSI: 0000000000000503 RDI: 0000000000000000 RBP: ffff8881daca6400 R08: ffffffff814a983a R09: ffffed103edcaa08 R10: ffffed103edcaa08 R11: 1ffff1103edcaa07 R12: 000000000000008c R13: 0000000000000080 R14: dffffc0000000000 R15: ffff8881daca6440 FS: 00007f89a3ba2700(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f89a4a2c24f CR3: 00000001e12ae000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 04 39 add $0x39,%al 2: 05 00 00 00 48 add $0x48000000,%eax 7: 89 d7 mov %edx,%edi 9: 48 83 cf 10 or $0x10,%rdi d: 48 89 04 39 mov %rax,(%rcx,%rdi,1) 11: 48 83 ca 18 or $0x18,%rdx 15: 4c 89 14 11 mov %r10,(%rcx,%rdx,1) 19: 4c 89 44 f1 20 mov %r8,0x20(%rcx,%rsi,8) 1e: 49 ff c1 inc %r9 21: 4c 89 09 mov %r9,(%rcx) 24: c3 retq 25: 90 nop 26: 4c 8b 04 24 mov (%rsp),%r8 * 2a: 65 48 8b 14 25 80 8d mov %gs:0x28d80,%rdx <-- trapping instruction 31: 02 00 33: 65 8b 0d c8 34 a2 7e mov %gs:0x7ea234c8(%rip),%ecx # 0x7ea23502 3a: f7 c1 00 01 1f 00 test $0x1f0100,%ecx