ebtables: ebtables: counters copy to user failed while replacing table BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: refcount_dec_and_test arch/x86/include/asm/refcount.h:75 [inline] IP: vb2_vmalloc_put+0x9/0x60 drivers/media/v4l2-core/videobuf2-vmalloc.c:68 PGD b3ef8067 P4D b3ef8067 PUD 96cc6067 PMD 0 Oops: 0002 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 0 PID: 9730 Comm: syz-executor.4 Not tainted 4.14.298-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 task: ffff8880b38564c0 task.stack: ffff888043fb8000 RIP: 0010:refcount_dec_and_test arch/x86/include/asm/refcount.h:75 [inline] RIP: 0010:vb2_vmalloc_put+0x9/0x60 drivers/media/v4l2-core/videobuf2-vmalloc.c:68 RSP: 0018:ffff888043fbfca8 EFLAGS: 00010297 RAX: ffff8880b38564c0 RBX: ffff888095925800 RCX: 1ffff1101670adb2 RDX: 0000000000000000 RSI: ffff8880b3856d70 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff8ae1614e R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888095925814 R14: 0000000000000000 R15: ffffffff84c27330 FS: 00005555559fc400(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000020 CR3: 00000000b3a52000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __vb2_buf_mem_free+0xfa/0x1d0 drivers/media/v4l2-core/videobuf2-core.c:240 __vb2_free_mem drivers/media/v4l2-core/videobuf2-core.c:409 [inline] __vb2_queue_free+0x60d/0x7a0 drivers/media/v4l2-core/videobuf2-core.c:454 vb2_core_queue_release+0x5b/0x70 drivers/media/v4l2-core/videobuf2-core.c:2054 v4l2_m2m_ctx_release+0x1a/0x30 drivers/media/v4l2-core/v4l2-mem2mem.c:701 vim2m_release+0xd4/0x120 drivers/media/platform/vim2m.c:959 v4l2_release+0xf4/0x190 drivers/media/v4l2-core/v4l2-dev.c:446 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 Code: e9 ca fc ff ff e8 68 a2 bc fc e9 96 fc ff ff e8 8e a4 bc fc e9 fd fe ff ff 66 0f 1f 84 00 00 00 00 00 55 48 89 fd e8 87 e4 92 fc ff 4d 20 0f 88 03 da 5f 02 74 06 5d e9 75 e4 92 fc e8 70 e4 RIP: refcount_dec_and_test arch/x86/include/asm/refcount.h:75 [inline] RSP: ffff888043fbfca8 RIP: vb2_vmalloc_put+0x9/0x60 drivers/media/v4l2-core/videobuf2-vmalloc.c:68 RSP: ffff888043fbfca8 CR2: 0000000000000020 ---[ end trace c06d9d7086afd12d ]--- ---------------- Code disassembly (best guess): 0: e9 ca fc ff ff jmpq 0xfffffccf 5: e8 68 a2 bc fc callq 0xfcbca272 a: e9 96 fc ff ff jmpq 0xfffffca5 f: e8 8e a4 bc fc callq 0xfcbca4a2 14: e9 fd fe ff ff jmpq 0xffffff16 19: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) 20: 00 00 22: 55 push %rbp 23: 48 89 fd mov %rdi,%rbp 26: e8 87 e4 92 fc callq 0xfc92e4b2 * 2b: f0 ff 4d 20 lock decl 0x20(%rbp) <-- trapping instruction 2f: 0f 88 03 da 5f 02 js 0x25fda38 35: 74 06 je 0x3d 37: 5d pop %rbp 38: e9 75 e4 92 fc jmpq 0xfc92e4b2 3d: e8 .byte 0xe8 3e: 70 e4 jo 0x24