slab kmalloc-8k start ffff8880256a8000 pointer offset 1480 size 8192 list_del corruption. prev->next should be ffff88802a5905c8, but was ffff88806c58e030. (prev=ffff8880256a85c8) ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:62! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 27298 Comm: syz.8.4193 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:__list_del_entry_valid_or_report+0x14a/0x1d0 lib/list_debug.c:62 Code: 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 8d 00 00 00 48 8b 55 00 48 89 e9 48 89 de 48 c7 c7 c0 df 1a 8c e8 c7 12 28 fc 90 <0f> 0b 4c 89 e7 e8 6c 0e 54 fd 48 89 ea 48 b8 00 00 00 00 00 fc ff RSP: 0018:ffffc9000465fce0 EFLAGS: 00010086 RAX: 000000000000006d RBX: ffff88802a5905c8 RCX: 0000000000000000 RDX: 000000000000006d RSI: ffffffff81e6f7e9 RDI: fffff520008cbf8d RBP: ffff8880256a85c8 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000080000001 R11: 0000000000000000 R12: ffff8880256a85c8 R13: ffff88802a5905c8 R14: ffff88802a5905d0 R15: ffff88802a5905a0 FS: 0000000000000000(0000) GS:ffff88809715a000(0063) knlGS:0000000056a91480 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f741f000 CR3: 000000005611a000 CR4: 0000000000352ef0 Call Trace: __list_del_entry_valid include/linux/list.h:132 [inline] __list_del_entry include/linux/list.h:223 [inline] list_del include/linux/list.h:237 [inline] __remove_wait_queue include/linux/wait.h:209 [inline] remove_wait_queue+0x30/0x180 kernel/sched/wait.c:74 ep_remove_wait_queue+0x85/0x1d0 fs/eventpoll.c:676 ep_unregister_pollwait fs/eventpoll.c:691 [inline] ep_clear_and_put+0x186/0x420 fs/eventpoll.c:916 ep_eventpoll_release+0x3e/0x60 fs/eventpoll.c:966 __fput+0x3ff/0xb40 fs/file_table.c:469 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x100/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] __do_fast_syscall_32+0x578/0x8c0 arch/x86/entry/syscall_32.c:310 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f82f6c Code: d2 74 05 c1 e8 0c 89 02 8b 5d fc 31 c0 c9 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 58 b8 77 00 00 00 cd 80 0f 0b 8d b6 00 00 00 00 b8 ad RSP: 002b:00000000ff82edfc EFLAGS: 00000202 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 000000000000001e RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__list_del_entry_valid_or_report+0x14a/0x1d0 lib/list_debug.c:62 Code: 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 8d 00 00 00 48 8b 55 00 48 89 e9 48 89 de 48 c7 c7 c0 df 1a 8c e8 c7 12 28 fc 90 <0f> 0b 4c 89 e7 e8 6c 0e 54 fd 48 89 ea 48 b8 00 00 00 00 00 fc ff RSP: 0018:ffffc9000465fce0 EFLAGS: 00010086 RAX: 000000000000006d RBX: ffff88802a5905c8 RCX: 0000000000000000 RDX: 000000000000006d RSI: ffffffff81e6f7e9 RDI: fffff520008cbf8d RBP: ffff8880256a85c8 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000080000001 R11: 0000000000000000 R12: ffff8880256a85c8 R13: ffff88802a5905c8 R14: ffff88802a5905d0 R15: ffff88802a5905a0 FS: 0000000000000000(0000) GS:ffff88809715a000(0063) knlGS:0000000056a91480 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f741f000 CR3: 000000005611a000 CR4: 0000000000352ef0 ---------------- Code disassembly (best guess): 0: d2 74 05 c1 shlb %cl,-0x3f(%rbp,%rax,1) 4: e8 0c 89 02 8b call 0x8b028915 9: 5d pop %rbp a: fc cld b: 31 c0 xor %eax,%eax d: c9 leave e: c3 ret f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 0f 1f 00 nopl (%rax) 21: 51 push %rcx 22: 52 push %rdx 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 ret 2e: 58 pop %rax 2f: b8 77 00 00 00 mov $0x77,%eax 34: cd 80 int $0x80 36: 0f 0b ud2 38: 8d b6 00 00 00 00 lea 0x0(%rsi),%esi 3e: b8 .byte 0xb8 3f: ad lods %ds:(%rsi),%eax