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BUG: KASAN: invalid-free in f_uac1_opts_c_srate_store+0x1d4/0x260 drivers/usb/gadget/function/f_uac1.c:1666
Free of addr ffff888029d9d7bd by task syz.5.13809/912

CPU: 2 UID: 0 PID: 912 Comm: syz.5.13809 Tainted: G S           L      syzkaller #0 PREEMPT(full) 
Tainted: [S]=CPU_OUT_OF_SPEC, [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_uac1_opts_c_srate_store+0x1d4/0x260 drivers/usb/gadget/function/f_uac1.c:1666
 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_pwrite64+0x161/0x1a0 fs/read_write.c:794
 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: 0023:0xf708efec
Code: Unable to access opcode bytes at 0xf708efc2.
RSP: 002b:00000000f547d50c EFLAGS: 00000292 ORIG_RAX: 00000000000000b5
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000080
RDX: 00000000000000b4 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 912:
 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_uac1_opts_c_srate_store+0x113/0x260 drivers/usb/gadget/function/f_uac1.c:1666
 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_pwrite64+0x161/0x1a0 fs/read_write.c:794
 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 ffff888029d9d780
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 61 bytes inside of
 94-byte region [ffff888029d9d780, ffff888029d9d7de)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29d9d
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801bc42280 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 15678, tgid 15655 (syz.6.7442), ts 1551592408021, free_ts 1476572256365
 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_pages_slowpath mm/page_alloc.c:4821 [inline]
 __alloc_frozen_pages_noprof+0x6ab/0x2dc0 mm/page_alloc.c:5317
 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]
 hash_netportnet4_add+0x270f/0x2fb0 net/netfilter/ipset/ip_set_hash_gen.h:978
 hash_netportnet4_uadt+0xcf7/0x17c0 net/netfilter/ipset/ip_set_hash_netportnet.c:323
 call_ad.isra.0+0x16e/0x940 net/netfilter/ipset/ip_set_core.c:1758
 ip_set_ad.isra.0+0x3eb/0x8a0 net/netfilter/ipset/ip_set_core.c:1848
 nfnetlink_rcv_msg+0x9d5/0x11e0 net/netfilter/nfnetlink.c:300
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556
 nfnetlink_rcv+0x1b3/0x440 net/netfilter/nfnetlink.c:667
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
page last free pid 4735 tgid 4735 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 free_pages_prepare+0x586/0xd80 mm/page_alloc.c:1451
 __free_contig_range_common+0x14f/0x250 mm/page_alloc.c:6897
 __free_contig_range mm/page_alloc.c:6942 [inline]
 free_pages_bulk+0xbd/0x200 mm/page_alloc.c:5257
 vm_area_free_pages+0xad/0x2b0 mm/vmalloc.c:3439
 vfree mm/vmalloc.c:3488 [inline]
 vfree+0x107/0x750 mm/vmalloc.c:3462
 kcov_put kernel/kcov.c:447 [inline]
 kcov_put kernel/kcov.c:443 [inline]
 kcov_close+0x34/0x60 kernel/kcov.c:554
 __fput+0x3ff/0xb50 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x951/0x2ae0 kernel/exit.c:1009
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1152
 get_signal+0x1ec7/0x21e0 kernel/signal.c:3046
 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101
 __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:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_int80_emulation+0x513/0x720 arch/x86/entry/syscall_32.c:175
 asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598

Memory state around the buggy address:
 ffff888029d9d680: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff888029d9d700: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
>ffff888029d9d780: 00 00 00 00 00 00 00 00 00 00 00 06 fc fc fc fc
                                        ^
 ffff888029d9d800: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
 ffff888029d9d880: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
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