================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x11c/0x7f70 kernel/locking/lockdep.c:5004 Read of size 8 at addr ffff888062e69020 by task syz-executor.5/17636 CPU: 0 PID: 17636 Comm: syz-executor.5 Not tainted 6.6.0-syzkaller-14142-g90b0c2b2edd1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0x163/0x540 mm/kasan/report.c:475 kasan_report+0x142/0x170 mm/kasan/report.c:588 __lock_acquire+0x11c/0x7f70 kernel/locking/lockdep.c:5004 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 ptp_release+0x96/0x1e0 drivers/ptp/ptp_chardev.c:146 ptp_read+0x17f/0x820 drivers/ptp/ptp_chardev.c:589 posix_clock_read+0x12f/0x190 kernel/time/posix-clock.c:51 vfs_read+0x289/0xb00 fs/read_write.c:468 ksys_read+0x1a0/0x2c0 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7fdea0c7cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fdea1a6d0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fdea0d9bf80 RCX: 00007fdea0c7cae9 RDX: 0000000000000069 RSI: 0000000020000040 RDI: 0000000000000003 RBP: 00007fdea0cc847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fdea0d9bf80 R15: 00007ffc6f1d8058 Allocated by task 17636: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] ptp_open+0xd9/0x430 drivers/ptp/ptp_chardev.c:112 posix_clock_open+0x155/0x1f0 kernel/time/posix-clock.c:134 chrdev_open+0x5ab/0x630 fs/char_dev.c:414 do_dentry_open+0x8fd/0x1590 fs/open.c:948 do_open fs/namei.c:3622 [inline] path_openat+0x2845/0x3280 fs/namei.c:3779 do_filp_open+0x234/0x490 fs/namei.c:3809 do_sys_openat2+0x13e/0x1d0 fs/open.c:1440 do_sys_open fs/open.c:1455 [inline] __do_sys_openat fs/open.c:1471 [inline] __se_sys_openat fs/open.c:1466 [inline] __x64_sys_openat+0x247/0x290 fs/open.c:1466 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b Freed by task 17637: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook mm/slub.c:1826 [inline] slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0x263/0x3a0 mm/slub.c:3822 ptp_release+0x1ce/0x1e0 drivers/ptp/ptp_chardev.c:150 ptp_read+0x17f/0x820 drivers/ptp/ptp_chardev.c:589 posix_clock_read+0x12f/0x190 kernel/time/posix-clock.c:51 vfs_read+0x289/0xb00 fs/read_write.c:468 ksys_read+0x1a0/0x2c0 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b The buggy address belongs to the object at ffff888062e68000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 4128 bytes inside of freed 8192-byte region [ffff888062e68000, ffff888062e6a000) The buggy address belongs to the physical page: page:ffffea00018b9a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x62e68 head:ffffea00018b9a00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888012c42280 0000000000000000 0000000000000001 raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 10563, tgid 10563 (syz-executor.0), ts 2088215031940, free_ts 2087483055838 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1544 [inline] get_page_from_freelist+0x339a/0x3530 mm/page_alloc.c:3312 __alloc_pages+0x255/0x670 mm/page_alloc.c:4568 alloc_pages_mpol+0x3de/0x640 mm/mempolicy.c:2133 alloc_slab_page+0x6a/0x160 mm/slub.c:1870 allocate_slab mm/slub.c:2017 [inline] new_slab+0x84/0x2f0 mm/slub.c:2070 ___slab_alloc+0xc85/0x1310 mm/slub.c:3223 __slab_alloc mm/slub.c:3322 [inline] __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x21d/0x300 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node+0xa7/0x230 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] kvmalloc_node+0x72/0x180 mm/util.c:607 kvmalloc include/linux/slab.h:738 [inline] kvzalloc include/linux/slab.h:746 [inline] snd_pcm_plugin_alloc+0x1be/0x7f0 sound/core/oss/pcm_plugin.c:74 snd_pcm_plug_alloc+0x15c/0x2a0 sound/core/oss/pcm_plugin.c:133 snd_pcm_oss_change_params_locked+0x2a21/0x3da0 sound/core/oss/pcm_oss.c:1052 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1116 [inline] snd_pcm_oss_make_ready+0x11d/0x340 sound/core/oss/pcm_oss.c:1175 snd_pcm_oss_sync+0x1bd/0xc30 sound/core/oss/pcm_oss.c:1742 snd_pcm_oss_release+0x11e/0x270 sound/core/oss/pcm_oss.c:2590 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1137 [inline] free_unref_page_prepare+0x92a/0xa50 mm/page_alloc.c:2347 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487 __slab_free+0x2f6/0x390 mm/slub.c:3715 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x14b/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x23/0x70 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6c/0x3c0 mm/slab.h:763 slab_alloc_node mm/slub.c:3478 [inline] slab_alloc mm/slub.c:3486 [inline] __kmem_cache_alloc_lru mm/slub.c:3493 [inline] kmem_cache_alloc+0x1be/0x350 mm/slub.c:3502 kmem_cache_zalloc include/linux/slab.h:711 [inline] alloc_buffer_head+0x2d/0x2a0 fs/buffer.c:3018 folio_alloc_buffers+0x34d/0x8e0 fs/buffer.c:925 create_empty_buffers+0x3a/0x740 fs/buffer.c:1650 ext4_block_write_begin+0x27d/0x1840 fs/ext4/inode.c:1036 ext4_da_write_begin+0x5e4/0xa40 fs/ext4/inode.c:2900 generic_perform_write+0x31b/0x630 mm/filemap.c:3918 ext4_buffered_write_iter+0xc6/0x350 fs/ext4/file.c:299 ext4_file_write_iter+0x1dc/0x19b0 Memory state around the buggy address: ffff888062e68f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888062e68f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888062e69000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888062e69080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888062e69100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================