================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: slab-use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] BUG: KASAN: slab-use-after-free in snd_usbmidi_error_timer+0x15d/0x660 sound/usb/midi.c:355 Read of size 4 at addr ffff8881433dcd10 by task syz.5.132/6536 CPU: 0 UID: 0 PID: 6536 Comm: syz.5.132 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] snd_usbmidi_error_timer+0x15d/0x660 sound/usb/midi.c:355 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5893 Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 0b 5f 03 11 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000b5374b0 EFLAGS: 00000206 RAX: 932492d4ea3bbb00 RBX: 0000000000000202 RCX: 932492d4ea3bbb00 RDX: 0000000000000001 RSI: ffffffff8dba9963 RDI: ffffffff8be33f80 RBP: ffff88802d772918 R08: ffffc9000b5379e0 R09: ffffc9000b537638 R10: dffffc0000000000 R11: fffff520016a6ec9 R12: 0000000000000001 R13: 0000000000000001 R14: ffffffff8e13a0e0 R15: ffff88802d771e00 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:330 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4191 [inline] slab_alloc_node mm/slub.c:4240 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4247 getname_flags+0xb8/0x540 fs/namei.c:146 getname include/linux/fs.h:2919 [inline] io_renameat_prep+0x211/0x3d0 io_uring/fs.c:70 io_init_req io_uring/io_uring.c:2197 [inline] io_submit_sqe io_uring/io_uring.c:2244 [inline] io_submit_sqes+0x917/0x1d30 io_uring/io_uring.c:2396 __do_sys_io_uring_enter io_uring/io_uring.c:3463 [inline] __se_sys_io_uring_enter+0x2df/0x2b20 io_uring/io_uring.c:3397 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd34118ec29 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd33f3d5038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007fd3413d6180 RCX: 00007fd34118ec29 RDX: 0000000000000217 RSI: 00000000000040f9 RDI: 0000000000000005 RBP: 00007fd341211e41 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000000a5 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd3413d6218 R14: 00007fd3413d6180 R15: 00007fff0cb2c778 Allocated by task 5940: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4376 [inline] __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4388 kmalloc_noprof include/linux/slab.h:909 [inline] usb_alloc_urb+0x46/0x150 drivers/usb/core/urb.c:75 snd_usbmidi_in_endpoint_create+0xb4/0xa30 sound/usb/midi.c:1348 snd_usbmidi_create_endpoints sound/usb/midi.c:1923 [inline] __snd_usbmidi_create+0x146b/0x2a70 sound/usb/midi.c:2648 snd_usb_midi_v2_create+0x43e6/0x4660 sound/usb/midi2.c:1178 snd_usb_create_quirk sound/usb/quirks.c:541 [inline] create_composite_quirk+0x1f6/0x4f0 sound/usb/quirks.c:49 usb_audio_probe+0xb78/0x1e10 sound/usb/card.c:976 usb_probe_interface+0x668/0xc30 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0x9e0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801 driver_probe_device+0x4f/0x430 drivers/base/dd.c:831 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3689 usb_set_configuration+0x1a87/0x20e0 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250 usb_probe_device+0x1c4/0x390 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0x9e0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801 driver_probe_device+0x4f/0x430 drivers/base/dd.c:831 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3689 usb_new_device+0xa39/0x16f0 drivers/usb/core/hub.c:2694 hub_port_connect drivers/usb/core/hub.c:5566 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x2958/0x4a20 drivers/usb/core/hub.c:5952 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 5940: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x18e/0x440 mm/slub.c:4894 free_urb_and_buffer sound/usb/midi.c:1309 [inline] snd_usbmidi_in_endpoint_delete+0xde/0x680 sound/usb/midi.c:1322 snd_usbmidi_free sound/usb/midi.c:1530 [inline] snd_usbmidi_rawmidi_free+0xae/0x160 sound/usb/midi.c:1591 snd_rawmidi_free+0x3bf/0x410 sound/core/rawmidi.c:1934 snd_rawmidi_dev_free+0x38/0x50 sound/core/rawmidi.c:1945 __snd_device_free+0x1d5/0x2e0 sound/core/device.c:76 snd_device_free_all+0xcf/0x180 sound/core/device.c:233 snd_card_do_free sound/core/init.c:587 [inline] release_card_device+0x75/0x1b0 sound/core/init.c:153 device_release+0x9c/0x1c0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22b/0x480 lib/kobject.c:737 snd_card_free_when_closed sound/core/init.c:618 [inline] snd_card_free+0x110/0x190 sound/core/init.c:650 usb_audio_probe+0x193f/0x1e10 sound/usb/card.c:1034 usb_probe_interface+0x668/0xc30 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0x9e0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801 driver_probe_device+0x4f/0x430 drivers/base/dd.c:831 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3689 usb_set_configuration+0x1a87/0x20e0 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250 usb_probe_device+0x1c4/0x390 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0x9e0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801 driver_probe_device+0x4f/0x430 drivers/base/dd.c:831 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3689 usb_new_device+0xa39/0x16f0 drivers/usb/core/hub.c:2694 hub_port_connect drivers/usb/core/hub.c:5566 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x2958/0x4a20 drivers/usb/core/hub.c:5952 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff8881433dcd00 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 16 bytes inside of freed 192-byte region [ffff8881433dcd00, ffff8881433dcdc0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1433dc flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 057ff00000000000 ffff88801a4413c0 ffffea00050cfac0 dead000000000004 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 10969843639, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2660 new_slab mm/slub.c:2714 [inline] ___slab_alloc+0xbeb/0x1420 mm/slub.c:3901 __slab_alloc mm/slub.c:3992 [inline] __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4402 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] call_usermodehelper_setup+0x8e/0x270 kernel/umh.c:362 kobject_uevent_env+0x65c/0x8c0 lib/kobject_uevent.c:628 really_probe+0x745/0x9e0 drivers/base/dd.c:709 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801 driver_probe_device+0x4f/0x430 drivers/base/dd.c:831 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 page_owner free stack trace missing Memory state around the buggy address: ffff8881433dcc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881433dcc80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8881433dcd00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881433dcd80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8881433dce00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ---------------- Code disassembly (best guess): 0: 51 push %rcx 1: 48 c7 44 24 20 00 00 movq $0x0,0x20(%rsp) 8: 00 00 a: 9c pushf b: 8f 44 24 20 pop 0x20(%rsp) f: f7 44 24 20 00 02 00 testl $0x200,0x20(%rsp) 16: 00 17: 75 56 jne 0x6f 19: f7 c3 00 02 00 00 test $0x200,%ebx 1f: 74 01 je 0x22 21: fb sti 22: 65 48 8b 05 0b 5f 03 mov %gs:0x11035f0b(%rip),%rax # 0x11035f35 29: 11 * 2a: 48 3b 44 24 28 cmp 0x28(%rsp),%rax <-- trapping instruction 2f: 0f 85 8b 00 00 00 jne 0xc0 35: 48 83 c4 30 add $0x30,%rsp 39: 5b pop %rbx 3a: 41 5c pop %r12 3c: 41 5d pop %r13 3e: 41 5e pop %r14