skbuff: skb_over_panic: text:ffffffff843b658e len:76 put:20 head:ffff888156edf800 data:ffff888156edf840 tail:0x8c end:0x80 dev:syztnl1 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:110! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 25840 Comm: syz-executor.1 Tainted: G W 5.10.76-syzkaller-01178-g4944ec82ebb9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:skb_panic+0x14f/0x160 net/core/skbuff.c:106 Code: 87 85 48 8b 75 c0 48 8b 55 b8 8b 4d d4 44 8b 45 d0 4c 8b 4d c8 b8 00 00 00 00 53 41 56 41 55 41 54 e8 3c 5d 89 fd 48 83 c4 20 <0f> 0b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 55 48 89 e5 41 RSP: 0018:ffffc90000007af8 EFLAGS: 00010282 RAX: 0000000000000086 RBX: ffff88810d6b8000 RCX: aa009dd4b2bb5400 RDX: 0000000000000502 RSI: 0000000000000502 RDI: 0000000000000000 RBP: ffffc90000007b40 R08: ffffffff81545288 R09: ffffed103ee095d8 R10: ffffed103ee095d8 R11: 0000000000000000 R12: ffff888156edf840 R13: 000000000000008c R14: 0000000000000080 R15: dffffc0000000000 FS: 0000555557426400(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff085dde4c1 CR3: 000000014c723000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: skb_over_panic+0x2c/0x30 net/core/skbuff.c:115 skb_put+0x205/0x210 net/core/skbuff.c:1877 add_grhead net/ipv6/mcast.c:1711 [inline] add_grec+0xf5e/0x1370 net/ipv6/mcast.c:1838 mld_send_cr net/ipv6/mcast.c:1964 [inline] mld_ifc_timer_expire+0x781/0xc50 net/ipv6/mcast.c:2471 call_timer_fn+0x35/0x280 kernel/time/timer.c:1420 expire_timers+0x21f/0x3b0 kernel/time/timer.c:1465 __run_timers+0x548/0x680 kernel/time/timer.c:1756 run_timer_softirq+0x69/0xf0 kernel/time/timer.c:1769 __do_softirq+0x27e/0x598 kernel/softirq.c:305 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x60/0x80 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:402 [inline] __irq_exit_rcu+0x128/0x150 kernel/softirq.c:432 irq_exit_rcu+0x9/0x10 kernel/softirq.c:444 sysvec_apic_timer_interrupt+0xbf/0xe0 arch/x86/kernel/apic/apic.c:1095 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:635 RIP: 0010:unwind_done arch/x86/include/asm/unwind.h:46 [inline] RIP: 0010:__unwind_start+0x378/0x420 arch/x86/kernel/unwind_frame.c:404 Code: df e8 2c aa 72 00 48 8b 45 d0 48 39 03 73 5d 4c 89 ef e8 db ec ff ff 48 b8 00 00 00 00 00 fc ff df 41 0f b6 04 04 84 c0 75 2b <41> 83 7d 00 00 0f 85 0d ff ff ff eb 35 44 89 e9 80 e1 07 80 c1 03 RSP: 0018:ffffc90001af77b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90001af7878 RCX: 00000000815bf001 RDX: 1ffff9200035ef0a RSI: ffffc90001af78d0 RDI: ffffc90001af7840 RBP: ffffc90001af7830 R08: dffffc0000000000 R09: ffffc90001af7840 R10: fffff5200035ef14 R11: 0000000000000000 R12: 1ffff9200035ef08 R13: ffffc90001af7840 R14: ffffc90001af0000 R15: ffffc90001af8000 unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0xdc/0x140 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x11b/0x1e0 kernel/stacktrace.c:121 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:357 ____kasan_slab_free+0x133/0x170 mm/kasan/common.c:360 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:368 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:1596 [inline] slab_free_freelist_hook+0xcc/0x1a0 mm/slub.c:1622 slab_free mm/slub.c:3204 [inline] kmem_cache_free+0xb5/0x1f0 mm/slub.c:3220 filename_create+0x4c7/0x770 fs/namei.c:262 user_path_create fs/namei.c:3600 [inline] do_symlinkat+0xd6/0x440 fs/namei.c:4055 __do_sys_symlink fs/namei.c:4081 [inline] __se_sys_symlink fs/namei.c:4079 [inline] __x64_sys_symlink+0x60/0x70 fs/namei.c:4079 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7ff085d5e3f7 Code: 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 58 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe5f4946e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff085d5e3f7 RDX: 00007ffe5f4947c7 RSI: 00007ff085db8fd1 RDI: 00007ffe5f4947b0 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffe5f494580 R10: 00007ffe5f494437 R11: 0000000000000206 R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000001 R15: 00007ffe5f4947b0 Modules linked in: ---[ end trace 34a892bf198b99f0 ]--- RIP: 0010:skb_panic+0x14f/0x160 net/core/skbuff.c:106 Code: 87 85 48 8b 75 c0 48 8b 55 b8 8b 4d d4 44 8b 45 d0 4c 8b 4d c8 b8 00 00 00 00 53 41 56 41 55 41 54 e8 3c 5d 89 fd 48 83 c4 20 <0f> 0b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 55 48 89 e5 41 RSP: 0018:ffffc90000007af8 EFLAGS: 00010282 RAX: 0000000000000086 RBX: ffff88810d6b8000 RCX: aa009dd4b2bb5400 RDX: 0000000000000502 RSI: 0000000000000502 RDI: 0000000000000000 RBP: ffffc90000007b40 R08: ffffffff81545288 R09: ffffed103ee095d8 R10: ffffed103ee095d8 R11: 0000000000000000 R12: ffff888156edf840 R13: 000000000000008c R14: 0000000000000080 R15: dffffc0000000000 FS: 0000555557426400(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff085dde4c1 CR3: 000000014c723000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: df e8 fucomip %st(0),%st 2: 2c aa sub $0xaa,%al 4: 72 00 jb 0x6 6: 48 8b 45 d0 mov -0x30(%rbp),%rax a: 48 39 03 cmp %rax,(%rbx) d: 73 5d jae 0x6c f: 4c 89 ef mov %r13,%rdi 12: e8 db ec ff ff callq 0xffffecf2 17: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1e: fc ff df 21: 41 0f b6 04 04 movzbl (%r12,%rax,1),%eax 26: 84 c0 test %al,%al 28: 75 2b jne 0x55 * 2a: 41 83 7d 00 00 cmpl $0x0,0x0(%r13) <-- trapping instruction 2f: 0f 85 0d ff ff ff jne 0xffffff42 35: eb 35 jmp 0x6c 37: 44 89 e9 mov %r13d,%ecx 3a: 80 e1 07 and $0x7,%cl 3d: 80 c1 03 add $0x3,%cl