Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 UID: 0 PID: 24623 Comm: syz.7.7657 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:strcmp+0x39/0xb0 lib/string.c:265 Code: df 41 54 55 53 48 89 fb 48 83 ec 08 eb 08 40 84 ed 74 61 4c 89 e6 48 89 df 48 83 c3 01 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 04 84 c0 75 58 48 89 f0 48 89 f2 0f b6 6b RSP: 0018:ffffc9000303fae8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffc90007ffb000 RDX: 0000000000000000 RSI: ffff888000318a01 RDI: 0000000000000000 RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8ec7cc30 R13: dffffc0000000000 R14: ffff8880753db700 R15: ffff888000318a01 FS: 0000000000000000(0000) GS:ffff888096bf3000(0063) knlGS:00000000f53edb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f721ea06 CR3: 000000004fea2000 CR4: 0000000000352ef0 Call Trace: remove_cache_mod kernel/trace/trace_events.c:948 [inline] cache_mod kernel/trace/trace_events.c:977 [inline] __ftrace_set_clr_event_nolock+0x8dc/0xbb0 kernel/trace/trace_events.c:1395 __ftrace_set_clr_event kernel/trace/trace_events.c:1410 [inline] ftrace_set_clr_event+0x1b7/0x3f0 kernel/trace/trace_events.c:1460 ftrace_event_write+0x259/0x2c0 kernel/trace/trace_events.c:1548 vfs_write+0x2aa/0x1050 fs/read_write.c:685 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf6ffefec Code: Unable to access opcode bytes at 0xf6ffefc2. RSP: 002b:00000000f53ed50c EFLAGS: 00000292 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000400 RDX: 0000000000000024 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:strcmp+0x39/0xb0 lib/string.c:265 Code: df 41 54 55 53 48 89 fb 48 83 ec 08 eb 08 40 84 ed 74 61 4c 89 e6 48 89 df 48 83 c3 01 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 04 84 c0 75 58 48 89 f0 48 89 f2 0f b6 6b RSP: 0018:ffffc9000303fae8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffc90007ffb000 RDX: 0000000000000000 RSI: ffff888000318a01 RDI: 0000000000000000 RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8ec7cc30 R13: dffffc0000000000 R14: ffff8880753db700 R15: ffff888000318a01 FS: 0000000000000000(0000) GS:ffff888096bf3000(0063) knlGS:00000000f53edb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000057a5d4ec CR3: 000000004fea2000 CR4: 0000000000352ef0 ---------------- Code disassembly (best guess): 0: df 41 54 filds 0x54(%rcx) 3: 55 push %rbp 4: 53 push %rbx 5: 48 89 fb mov %rdi,%rbx 8: 48 83 ec 08 sub $0x8,%rsp c: eb 08 jmp 0x16 e: 40 84 ed test %bpl,%bpl 11: 74 61 je 0x74 13: 4c 89 e6 mov %r12,%rsi 16: 48 89 df mov %rbx,%rdi 19: 48 83 c3 01 add $0x1,%rbx 1d: 48 89 f8 mov %rdi,%rax 20: 48 89 fa mov %rdi,%rdx 23: 48 c1 e8 03 shr $0x3,%rax 27: 83 e2 07 and $0x7,%edx * 2a: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax <-- trapping instruction 2f: 38 d0 cmp %dl,%al 31: 7f 04 jg 0x37 33: 84 c0 test %al,%al 35: 75 58 jne 0x8f 37: 48 89 f0 mov %rsi,%rax 3a: 48 89 f2 mov %rsi,%rdx 3d: 0f .byte 0xf 3e: b6 6b mov $0x6b,%dh