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BUG: KASAN: invalid-free in f_uac2_opts_p_srate_store+0x1d4/0x260 drivers/usb/gadget/function/f_uac2.c:2087
Free of addr ffff888052af0086 by task syz.7.4035/23570

CPU: 2 UID: 0 PID: 23570 Comm: syz.7.4035 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report_invalid_free+0xb8/0x190 mm/kasan/report.c:557
 check_slab_allocation+0xe1/0xf0 mm/kasan/common.c:230
 kasan_slab_pre_free include/linux/kasan.h:199 [inline]
 slab_free_hook mm/slub.c:2622 [inline]
 slab_free mm/slub.c:6377 [inline]
 kfree+0x1b6/0x6c0 mm/slub.c:6692
 f_uac2_opts_p_srate_store+0x1d4/0x260 drivers/usb/gadget/function/f_uac2.c:2087
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7fa2fec
Code: Unable to access opcode bytes at 0xf7fa2fc2.
RSP: 002b:00000000f546650c EFLAGS: 00000292 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000080000440
RDX: 000000000000002e RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 23570:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5334 [inline]
 __kmalloc_node_track_caller_noprof+0x331/0x830 mm/slub.c:5471
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x51/0xe0 mm/util.c:84
 f_uac2_opts_p_srate_store+0x113/0x260 drivers/usb/gadget/function/f_uac2.c:2087
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

The buggy address belongs to the object at ffff888052af0080
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 6 bytes inside of
 47-byte region [ffff888052af0080, ffff888052af00af)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x52af0
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000000 ffff88801bc428c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800200020 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 0xd2c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5156, tgid 5156 (udevd), ts 1166507736953, free_ts 1166499453115
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
 alloc_slab_page mm/slub.c:3266 [inline]
 allocate_slab mm/slub.c:3380 [inline]
 new_slab+0xa2/0x640 mm/slub.c:3426
 refill_objects+0xe3/0x410 mm/slub.c:7310
 refill_sheaf mm/slub.c:2804 [inline]
 __pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675
 alloc_from_pcs mm/slub.c:4773 [inline]
 slab_alloc_node mm/slub.c:4905 [inline]
 __do_kmalloc_node mm/slub.c:5333 [inline]
 __kmalloc_noprof+0x66d/0x820 mm/slub.c:5359
 _kmalloc_noprof include/linux/slab.h:992 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 tomoyo_encode2+0xfb/0x3c0 security/tomoyo/realpath.c:45
 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x18c/0x690 security/tomoyo/realpath.c:283
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x276/0x460 security/tomoyo/file.c:827
 security_inode_getattr+0x116/0x280 security/security.c:1895
 vfs_getattr fs/stat.c:259 [inline]
 vfs_fstat+0x4b/0xe0 fs/stat.c:281
 __do_sys_newfstat+0x8b/0x110 fs/stat.c:551
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 20636 tgid 20636 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950
 __pagetable_free include/linux/mm.h:3695 [inline]
 pagetable_free include/linux/mm.h:3719 [inline]
 pagetable_dtor_free include/linux/mm.h:3818 [inline]
 __pgd_free include/asm-generic/pgalloc.h:303 [inline]
 _pgd_free arch/x86/mm/pgtable.c:308 [inline]
 pgd_free+0x3eb/0x540 arch/x86/mm/pgtable.c:370
 mm_free_pgd kernel/fork.c:590 [inline]
 __mmdrop+0x139/0x530 kernel/fork.c:733
 mmdrop include/linux/sched/mm.h:55 [inline]
 mmdrop_sched include/linux/sched/mm.h:83 [inline]
 mmdrop_lazy_tlb_sched include/linux/sched/mm.h:110 [inline]
 finish_task_switch.isra.0+0xb40/0x10c0 kernel/sched/core.c:5392
 context_switch kernel/sched/core.c:5513 [inline]
 __schedule+0x1264/0x6730 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7326
 do_nanosleep+0x113/0x500 kernel/time/hrtimer.c:2399
 hrtimer_nanosleep+0x14f/0x350 kernel/time/hrtimer.c:2445
 common_nsleep+0xa1/0xd0 kernel/time/posix-timers.c:1360
 __do_sys_clock_nanosleep_time32 kernel/time/posix-timers.c:1434 [inline]
 __se_sys_clock_nanosleep_time32 kernel/time/posix-timers.c:1411 [inline]
 __ia32_sys_clock_nanosleep_time32+0x352/0x480 kernel/time/posix-timers.c:1411
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 do_int80_emulation+0x14b/0x720 arch/x86/entry/syscall_32.c:172
 asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598

Memory state around the buggy address:
 ffff888052aeff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888052af0000: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
>ffff888052af0080: 00 00 00 00 00 07 fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff888052af0100: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
 ffff888052af0180: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
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