================================================================== BUG: KASAN: slab-use-after-free in rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 Read of size 1 at addr ffff88802ada6200 by task syz.1.2773/15401 CPU: 0 UID: 0 PID: 15401 Comm: syz.1.2773 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:574 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire+0x84/0x350 kernel/locking/lockdep.c:5842 rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 spin_lock include/linux/spinlock_rt.h:45 [inline] __wake_up_common_lock+0x2f/0x1e0 kernel/sched/wait.c:124 snd_pcm_post_stop sound/core/pcm_native.c:1570 [inline] snd_pcm_action_single sound/core/pcm_native.c:-1 [inline] snd_pcm_action sound/core/pcm_native.c:1417 [inline] snd_pcm_stop+0x428/0x550 sound/core/pcm_native.c:1590 loopback_check_format sound/drivers/aloop.c:400 [inline] loopback_trigger+0x11ff/0x1cf0 sound/drivers/aloop.c:421 snd_pcm_do_start sound/core/pcm_native.c:1478 [inline] snd_pcm_action_single sound/core/pcm_native.c:1334 [inline] snd_pcm_action sound/core/pcm_native.c:1417 [inline] snd_pcm_start+0x43d/0x5d0 sound/core/pcm_native.c:1525 __snd_pcm_lib_xfer+0x175a/0x1d10 sound/core/pcm_lib.c:2405 snd_pcm_oss_write3+0x1ab/0x300 sound/core/oss/pcm_oss.c:1247 snd_pcm_oss_write2+0x2c2/0x440 sound/core/oss/pcm_oss.c:1391 snd_pcm_oss_sync1+0x180/0x520 sound/core/oss/pcm_oss.c:1625 snd_pcm_oss_sync+0xab2/0xfc0 sound/core/oss/pcm_oss.c:1690 snd_pcm_oss_release+0x102/0x250 sound/core/oss/pcm_oss.c:2584 __fput+0x461/0xa70 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe60f53c819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff84ce5258 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fe60f7b7da0 RCX: 00007fe60f53c819 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fe60f7b7da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007fe60f7b7cb0 R11: 0000000000000246 R12: 0000000000118924 R13: 00007fe60f7b609c R14: 0000000000118674 R15: 00007fe60f7b6090 Allocated by task 15402: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3a6/0x690 mm/slub.c:5415 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] snd_pcm_attach_substream+0x5b7/0xb20 sound/core/pcm.c:938 snd_pcm_open_substream+0xbd/0x2420 sound/core/pcm_native.c:2797 snd_pcm_oss_open_file sound/core/oss/pcm_oss.c:2448 [inline] snd_pcm_oss_open+0xf90/0x1c20 sound/core/oss/pcm_oss.c:2529 chrdev_open+0x4d0/0x5f0 fs/char_dev.c:411 do_dentry_open+0x83d/0x13e0 fs/open.c:947 vfs_open+0x3b/0x350 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x2e43/0x38a0 fs/namei.c:4858 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15402: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6246 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6561 snd_pcm_detach_substream+0x1c8/0x270 sound/core/pcm.c:1003 snd_pcm_oss_release_file sound/core/oss/pcm_oss.c:2407 [inline] snd_pcm_oss_release+0x184/0x250 sound/core/oss/pcm_oss.c:2586 __fput+0x461/0xa70 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802ada6000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 512 bytes inside of freed 2048-byte region [ffff88802ada6000, ffff88802ada6800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2ada0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88801a022000 dead000000000100 dead000000000122 head: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 14360292502, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x27c8/0x2840 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7251 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __kmalloc_cache_noprof+0x44e/0x690 mm/slub.c:5410 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] usb_create_ep_devs+0x59/0x230 drivers/usb/core/endpoint.c:149 usb_new_device+0xae7/0x16e0 drivers/usb/core/hub.c:2725 register_root_hub+0x270/0x5f0 drivers/usb/core/hcd.c:990 usb_add_hcd+0xba1/0x10b0 drivers/usb/core/hcd.c:2987 dummy_hcd_probe+0x134/0x270 drivers/usb/gadget/udc/dummy_hcd.c:2704 platform_probe+0xf9/0x190 drivers/base/platform.c:1418 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x267/0xaf0 drivers/base/dd.c:709 __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871 driver_probe_device+0x4f/0x240 drivers/base/dd.c:901 page_owner free stack trace missing Memory state around the buggy address: ffff88802ada6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802ada6180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802ada6200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802ada6280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802ada6300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================