Hi On Mon, Feb 27, 2023 at 2:30 PM Sanan Hasanov <sanan.hasanov@xxxxxxxxxxxxxxx> wrote: > > Good day, dear maintainers, > > We found a bug using a modified kernel configuration file used by syzbot. > > We enhanced the coverage of the configuration file using our tool, klocalizer. > > Kernel Branch: 6.2.0-next-20230221 > Kernel config: https://drive.google.com/file/d/1QKAQV11zjOwISifUc-skRBoTo3EXhutY/view?usp=share_link > C Reproducer: Unfortunately, there is no reproducer yet. I downloaded 6.2.0-next-20230221 (wget https://kernel.source.codeaurora.cn/pub/scm/linux/kernel/git/next/linux-next.git/snapshot/linux-next-next-20230221.tar.gz) and compile the kernel using above kernel config, and started syzkaller: http://154.220.3.120:56700/ Hope I can reproduce the bug and chase down the cause of the bug. You are welcome ;-) Thanks Zhouyi > > Thank you! > > Best regards, > Sanan Hasanov > > BUG: kernel NULL pointer dereference, address: 0000000000000000 > #PF: supervisor instruction fetch in kernel mode > #PF: error_code(0x0010) - not-present page > PGD 53756067 P4D 53756067 PUD 0 > Oops: 0010 [#1] PREEMPT SMP KASAN > CPU: 7 PID: 0 Comm: swapper/7 Not tainted 6.2.0-next-20230221 #1 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 > RIP: 0010:0x0 > Code: Unable to access opcode bytes at 0xffffffffffffffd6. > RSP: 0018:ffffc900003f8e48 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: ffff888100833900 RCX: 00000000b9582f6c > RDX: 1ffff11020106853 RSI: ffffffff816b2769 RDI: ffff888043f64708 > RBP: 000000000000000c R08: 0000000000000000 R09: ffffffff900b895f > R10: fffffbfff201712b R11: 000000000008e001 R12: dffffc0000000000 > R13: ffffc900003f8ec8 R14: ffff888043f64708 R15: 000000000000000b > FS: 0000000000000000(0000) GS:ffff888119f80000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffffffffffd6 CR3: 0000000054e64000 CR4: 0000000000350ee0 > Call Trace: > <IRQ> > rcu_core+0x85d/0x1960 > __do_softirq+0x2e5/0xae2 > __irq_exit_rcu+0x11d/0x190 > irq_exit_rcu+0x9/0x20 > sysvec_apic_timer_interrupt+0x97/0xc0 > </IRQ> > <TASK> > asm_sysvec_apic_timer_interrupt+0x1a/0x20 > RIP: 0010:default_idle+0xf/0x20 > Code: 89 07 49 c7 c0 08 00 00 00 4d 29 c8 4c 01 c7 4c 29 c2 e9 76 ff ff ff cc cc cc cc f3 0f 1e fa eb 07 0f 00 2d e3 8a 34 00 fb f4 <fa> c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3 0f 1e fa 65 > RSP: 0018:ffffc9000017fe00 EFLAGS: 00000202 > RAX: 0000000000dfbea1 RBX: dffffc0000000000 RCX: ffffffff89b1da9c > RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 > RBP: 0000000000000007 R08: 0000000000000001 R09: ffff888119fb6c23 > R10: ffffed10233f6d84 R11: dffffc0000000000 R12: 0000000000000003 > R13: ffff888100833900 R14: ffffffff8e112850 R15: 0000000000000000 > default_idle_call+0x67/0xa0 > do_idle+0x361/0x440 > cpu_startup_entry+0x18/0x20 > start_secondary+0x256/0x300 > secondary_startup_64_no_verify+0xce/0xdb > </TASK> > Modules linked in: > CR2: 0000000000000000 > ---[ end trace 0000000000000000 ]--- > RIP: 0010:0x0 > Code: Unable to access opcode bytes at 0xffffffffffffffd6. > RSP: 0018:ffffc900003f8e48 EFLAGS: 00010246 > > RAX: 0000000000000000 RBX: ffff888100833900 RCX: 00000000b9582f6c > RDX: 1ffff11020106853 RSI: ffffffff816b2769 RDI: ffff888043f64708 > RBP: 000000000000000c R08: 0000000000000000 R09: ffffffff900b895f > R10: fffffbfff201712b R11: 000000000008e001 R12: dffffc0000000000 > R13: ffffc900003f8ec8 R14: ffff888043f64708 R15: 000000000000000b > FS: 0000000000000000(0000) GS:ffff888119f80000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffffffffffd6 CR3: 0000000054e64000 CR4: 0000000000350ee0 > ---------------- > Code disassembly (best guess): > 0: 89 07 mov %eax,(%rdi) > 2: 49 c7 c0 08 00 00 00 mov $0x8,%r8 > 9: 4d 29 c8 sub %r9,%r8 > c: 4c 01 c7 add %r8,%rdi > f: 4c 29 c2 sub %r8,%rdx > 12: e9 76 ff ff ff jmp 0xffffff8d > 17: cc int3 > 18: cc int3 > 19: cc int3 > 1a: cc int3 > 1b: f3 0f 1e fa endbr64 > 1f: eb 07 jmp 0x28 > 21: 0f 00 2d e3 8a 34 00 verw 0x348ae3(%rip) # 0x348b0b > 28: fb sti > 29: f4 hlt > * 2a: fa cli <-- trapping instruction > 2b: c3 ret > 2c: 66 66 2e 0f 1f 84 00 data16 cs nopw 0x0(%rax,%rax,1) > 33: 00 00 00 00 > 37: 0f 1f 40 00 nopl 0x0(%rax) > 3b: f3 0f 1e fa endbr64 > 3f: 65 gs >
