Hello, When using Healer to fuzz the latest Linux kernel, the following crash was triggered. HEAD commit: 4b93c544e90e-thunderbolt: test: split up test cases git tree: upstream console output: https://drive.google.com/file/d/1hPcef9aADlFdNS6_ujlRpU-HoebC2uXF/view?usp=sharing kernel config: https://drive.google.com/file/d/1c0u2EeRDhRO-ZCxr9MP2VvAtJd6kfg-p/view?usp=sharing Syzlang reproducer: https://drive.google.com/file/d/1zvo1s72quEdpM5xQ7zQxU8oOLiZpoFTN/view?usp=sharing Similar report: [1] https://groups.google.com/g/syzkaller-bugs/c/B8I1zHVqoxk/m/8PlQrZRbAwAJ [2] https://groups.google.com/g/syzkaller-bugs/c/NLim2pbuazk/m/xd3MD-Q-BQAJ Sorry, I don't have a C reproducer for this crash but have a Syzlang reproducer. Also, hope the symbolized report can help. Here are the instructions on how to execute Syzlang prog: https://github.com/google/syzkaller/blob/master/docs/executing_syzkaller_programs.md If you fix this issue, please add the following tag to the commit: Reported-by: Hao Sun <sunhao.th@xxxxxxxxx> ------------[ cut here ]------------ WARNING: CPU: 3 PID: 8715 at drivers/block/floppy.c:999 schedule_bh+0x5f/0x70 drivers/block/floppy.c:999 Modules linked in: CPU: 3 PID: 8715 Comm: kworker/u8:2 Not tainted 5.14.0+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: floppy floppy_work_workfn RIP: 0010:schedule_bh+0x5f/0x70 drivers/block/floppy.c:999 Code: 27 67 ff fc 48 89 2d 40 d9 db 0b 5b 48 c7 c2 40 69 48 8c 48 8b 35 11 de db 0b bf 08 00 00 00 5d e9 56 d5 d4 fc e8 01 67 ff fc <0f> 0b eb d1 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 e8 eb 66 ff fc RSP: 0018:ffffc900008a0dc8 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff88801badd580 RDX: 0000000000000000 RSI: ffff88801badd580 RDI: 0000000000000002 RBP: ffffffff8476e0d0 R08: ffffffff8476b93f R09: 0000000000000000 R10: 0000000000000007 R11: fffffbfff1890d28 R12: 0000000000000001 R13: ffffffff8476e0d0 R14: 0000000000000000 R15: ffff888010c75000 FS: 0000000000000000(0000) GS:ffff888135d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000048b8e0 CR3: 000000002ee93000 CR4: 0000000000350ee0 Call Trace: <IRQ> floppy_interrupt+0x228/0x340 drivers/block/floppy.c:1765 floppy_hardint+0x256/0x320 arch/x86/include/asm/floppy.h:66 __handle_irq_event_percpu+0xfd/0x900 kernel/irq/handle.c:156 handle_irq_event_percpu+0x76/0x160 kernel/irq/handle.c:196 handle_irq_event+0xa1/0x130 kernel/irq/handle.c:213 handle_edge_irq+0x24a/0x8a0 kernel/irq/chip.c:822 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq arch/x86/kernel/irq.c:231 [inline] __common_interrupt+0x9d/0x210 arch/x86/kernel/irq.c:250 common_interrupt+0x9f/0xd0 arch/x86/kernel/irq.c:240 </IRQ> asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629 RIP: 0010:slow_down_io arch/x86/include/asm/paravirt.h:55 [inline] RIP: 0010:outb_p arch/x86/include/asm/io.h:334 [inline] RIP: 0010:fdc_outb drivers/block/floppy.c:602 [inline] RIP: 0010:reset_fdc+0x328/0x8a0 drivers/block/floppy.c:1817 Code: ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 11 00 0f 85 e8 04 00 00 48 8d 14 9b 48 8b 14 d5 d0 97 52 90 83 c2 04 ee <48> c7 c3 e0 47 7f 8b 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 RSP: 0018:ffffc90001d0fcf8 EFLAGS: 00000202 RAX: 00000000ffffff83 RBX: 0000000000000000 RCX: 1ffffffff20a52fa RDX: 00000000000003f4 RSI: ffff88801badd580 RDI: ffffffff905297d0 RBP: 0000000000000062 R08: ffffffff8476f60f R09: 0000000000000044 R10: 0000000000000001 R11: fffffbfff1fa0127 R12: 0000000000000001 R13: 0000000000000000 R14: dffffc0000000000 R15: 000000000000fffd process_one_work+0x9df/0x16d0 kernel/workqueue.c:2297 worker_thread+0x90/0xed0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: ba 00 00 00 00 mov $0x0,%edx 5: 00 fc add %bh,%ah 7: ff (bad) 8: df 48 89 fisttps -0x77(%rax) b: f9 stc c: 48 c1 e9 03 shr $0x3,%rcx 10: 80 3c 11 00 cmpb $0x0,(%rcx,%rdx,1) 14: 0f 85 e8 04 00 00 jne 0x502 1a: 48 8d 14 9b lea (%rbx,%rbx,4),%rdx 1e: 48 8b 14 d5 d0 97 52 mov -0x6fad6830(,%rdx,8),%rdx 25: 90 26: 83 c2 04 add $0x4,%edx 29: ee out %al,(%dx) * 2a: 48 c7 c3 e0 47 7f 8b mov $0xffffffff8b7f47e0,%rbx <-- trapping instruction 31: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 38: fc ff df 3b: 48 89 da mov %rbx,%rdx 3e: 48 rex.W 3f: c1 .byte 0xc1
