================================================================== BUG: KASAN: slab-use-after-free in rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 Read of size 1 at addr ffff88808c66a200 by task syz.4.5443/24011 CPU: 0 UID: 0 PID: 24011 Comm: syz.4.5443 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP 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: 0033:0x7fabbbf1cdd9 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:00007fff183f43d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fabbc197da0 RCX: 00007fabbbf1cdd9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fabbc197da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007fabbc197cb0 R11: 0000000000000246 R12: 0000000000134803 R13: 00007fabbc195fac R14: 0000000000134590 R15: 00007fabbc195fa0 Allocated by task 24018: 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 24018: 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][ 1264.377310][T24011] kfree+0x1c5/0x6c0 slab_free_hook mm/slub.c:2689 [inline][ 1264.377310][T24011] kfree+0x1c5/0x6c0 slab_free mm/slub.c:6246 [inline][ 1264.377310][T24011] kfree+0x1c5/0x6c0 kfree+0x1c5/0x6c mm/slub.c:6561[ 1264.377310][T24011] kfree+0x1c5/0x6c0 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 ffff88808c66a000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 512 bytes inside of freed 2048-byte region [ffff88808c66a000, ffff88808c66a800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88808c66f000 pfn:0x8c668 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000240(workingset|head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000240 ffff88801a010000 ffffea00017cb610 ffffea000076b010 raw: ffff88808c66f000 0000000800080005 00000000f5000000 0000000000000000 head: 0080000000000240 ffff88801a010000 ffffea00017cb610 ffffea000076b010 head: ffff88808c66f000 0000000800080005 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 5260, tgid 5260 (dhcpcd), ts 1065309978522, free_ts 1065084287822 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] __do_kmalloc_node mm/slub.c:5294 [inline] __kvmalloc_node_noprof+0x6f4/0x8e0 mm/slub.c:6828 kvmalloc_array_node_noprof include/linux/slab.h:1216 [inline] __ptr_ring_init_queue_alloc_noprof include/linux/ptr_ring.h:481 [inline] ptr_ring_init_noprof include/linux/ptr_ring.h:499 [inline] page_pool_init net/core/page_pool.c:262 [inline] page_pool_create_percpu+0x2ea/0xba0 net/core/page_pool.c:347 nsim_create_page_pool drivers/net/netdevsim/netdev.c:429 [inline] nsim_init_napi drivers/net/netdevsim/netdev.c:452 [inline] nsim_open+0x3c4/0xa20 drivers/net/netdevsim/netdev.c:508 __dev_open+0x44d/0x830 net/core/dev.c:1702 __dev_change_flags+0x2fa/0x7e0 net/core/dev.c:9755 netif_change_flags+0x88/0x1a0 net/core/dev.c:9818 dev_change_flags+0x130/0x270 net/core/dev_api.c:68 devinet_ioctl+0x9f2/0x1b30 net/ipv4/devinet.c:1199 inet_ioctl+0x42a/0x560 net/ipv4/af_inet.c:1011 sock_do_ioctl+0x101/0x320 net/socket.c:1313 page last free pid 21049 tgid 21049 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0xfa6/0x10f0 mm/page_alloc.c:2943 __slab_free+0x252/0x2a0 mm/slub.c:5608 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4905 anon_vma_chain_alloc mm/rmap.c:142 [inline] __anon_vma_prepare+0xcb/0x4a0 mm/rmap.c:194 __vmf_anon_prepare mm/memory.c:3813 [inline] vmf_anon_prepare mm/internal.h:503 [inline] do_cow_fault mm/memory.c:5913 [inline] do_fault mm/memory.c:6029 [inline] do_pte_missing+0x1e57/0x2950 mm/memory.c:4550 handle_pte_fault mm/memory.c:6411 [inline] __handle_mm_fault mm/memory.c:6549 [inline] handle_mm_fault+0xd0a/0x13c0 mm/memory.c:6718 do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 Memory state around the buggy address: ffff88808c66a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808c66a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808c66a200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808c66a280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808c66a300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================