================================================================== 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 ffff888026d1ff10 by task syz.2.56/6075 CPU: 1 UID: 0 PID: 6075 Comm: syz.2.56 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+0x17b/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+0x283/0x870 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:arch_test_and_set_bit arch/x86/include/asm/bitops.h:137 [inline] RIP: 0010:arch_test_and_set_bit_lock arch/x86/include/asm/bitops.h:143 [inline] RIP: 0010:test_and_set_bit_lock include/asm-generic/bitops/instrumented-lock.h:58 [inline] RIP: 0010:folio_trylock include/linux/pagemap.h:1096 [inline] RIP: 0010:next_uptodate_folio+0x38f/0x5d0 mm/filemap.c:3614 Code: 83 e6 01 31 ff e8 31 38 c8 ff 49 83 e5 01 0f 85 11 02 00 00 4c 89 e7 be 08 00 00 00 e8 4a b3 2b 00 31 f6 f0 49 0f ba 2c 24 00 <41> 0f 93 c5 40 0f 92 c6 bf 02 00 00 00 e8 1f 36 c8 ff 45 84 ed 75 RSP: 0000:ffffc9000466f9b8 EFLAGS: 00000246 RAX: ffffffff81f77a01 RBX: 00000000000000df RCX: ffffffff81f77a56 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffea0001d22580 RBP: 1ffffd40003a44b1 R08: ffffea0001d22587 R09: 1ffffd40003a44b0 R10: dffffc0000000000 R11: fffff940003a44b1 R12: ffffea0001d22580 R13: 0000000000000000 R14: ffffea0001d22588 R15: ffffc9000466fb40 filemap_map_pages+0x102b/0x1740 mm/filemap.c:3789 do_fault_around mm/memory.c:5531 [inline] do_read_fault mm/memory.c:5564 [inline] do_fault mm/memory.c:5707 [inline] do_pte_missing mm/memory.c:4234 [inline] handle_pte_fault mm/memory.c:6052 [inline] __handle_mm_fault+0x34ac/0x5440 mm/memory.c:6195 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0023:0xf706eb9b Code: 24 14 83 e9 01 c1 e1 0e 89 f0 89 fa 0f ac fe 03 0f ac d0 06 8d 14 0b 89 f1 25 ff 3f 00 00 83 e1 07 01 d0 ba 01 00 00 00 d3 e2 <84> 90 20 20 00 00 0f 85 69 fd ff ff e9 0a fe ff ff e8 0f 3c fe ff RSP: 002b:00000000f751f9e0 EFLAGS: 00010202 RAX: 000000000c30aa5b RBX: 000000000c230000 RCX: 0000000000000004 RDX: 0000000000000010 RSI: 00000000f03f52dc RDI: 00000000ffffffff RBP: 00000000f7f25610 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 9: 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_midiman sound/usb/midi.c:2363 [inline] __snd_usbmidi_create+0x2223/0x2a70 sound/usb/midi.c:2646 snd_usb_midi_v2_create+0x43e6/0x4660 sound/usb/midi2.c:1178 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+0x26a/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+0x26a/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+0x70e/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 9: 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+0x3bc/0x410 sound/core/rawmidi.c:1934 snd_rawmidi_dev_free+0x38/0x50 sound/core/rawmidi.c:1945 __snd_device_free+0x1d2/0x2e0 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+0x26a/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+0x26a/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+0x70e/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 ffff888026d1ff00 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 16 bytes inside of freed 192-byte region [ffff888026d1ff00, ffff888026d1ffc0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x26d1f flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801a4413c0 dead000000000100 dead000000000122 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 9693441177, free_ts 9693107974 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] __do_kmalloc_node mm/slub.c:4375 [inline] __kvmalloc_node_noprof+0x429/0x5f0 mm/slub.c:5067 bucket_table_alloc lib/rhashtable.c:186 [inline] rhashtable_init_noprof+0x4ee/0xbb0 lib/rhashtable.c:1075 rhltable_init_noprof+0x1e/0x60 lib/rhashtable.c:1104 sta_info_init+0x54/0x130 net/mac80211/sta_info.c:1623 ieee80211_alloc_hw_nm+0x7f0/0x1f20 net/mac80211/main.c:911 mac80211_hwsim_new_radio+0x1ee/0x5340 drivers/net/wireless/virtual/mac80211_hwsim.c:5195 init_mac80211_hwsim+0x45e/0x580 drivers/net/wireless/virtual/mac80211_hwsim.c:6920 do_one_initcall+0x233/0x820 init/main.c:1269 do_initcall_level+0x104/0x190 init/main.c:1331 do_initcalls+0x59/0xa0 init/main.c:1347 page last free pid 918 tgid 918 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 vfree+0x25a/0x400 mm/vmalloc.c:3434 delayed_vfree_work+0x55/0x80 mm/vmalloc.c:3353 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+0x70e/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 Memory state around the buggy address: ffff888026d1fe00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888026d1fe80: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888026d1ff00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888026d1ff80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888026d20000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ---------------- Code disassembly (best guess): 0: 83 e6 01 and $0x1,%esi 3: 31 ff xor %edi,%edi 5: e8 31 38 c8 ff call 0xffc8383b a: 49 83 e5 01 and $0x1,%r13 e: 0f 85 11 02 00 00 jne 0x225 14: 4c 89 e7 mov %r12,%rdi 17: be 08 00 00 00 mov $0x8,%esi 1c: e8 4a b3 2b 00 call 0x2bb36b 21: 31 f6 xor %esi,%esi 23: f0 49 0f ba 2c 24 00 lock btsq $0x0,(%r12) * 2a: 41 0f 93 c5 setae %r13b <-- trapping instruction 2e: 40 0f 92 c6 setb %sil 32: bf 02 00 00 00 mov $0x2,%edi 37: e8 1f 36 c8 ff call 0xffc8365b 3c: 45 84 ed test %r13b,%r13b 3f: 75 .byte 0x75