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BUG: KASAN: slab-use-after-free in sysfs_remove_file_ns+0x63/0x70 fs/sysfs/file.c:510
Read of size 8 at addr ffff88802b011430 by task syz.2.1891/13072

CPU: 0 UID: 0 PID: 13072 Comm: syz.2.1891 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xcd/0x630 mm/kasan/report.c:482
 kasan_report+0xe0/0x110 mm/kasan/report.c:595
 sysfs_remove_file_ns+0x63/0x70 fs/sysfs/file.c:510
 sysfs_remove_file include/linux/sysfs.h:770 [inline]
 driver_remove_file drivers/base/driver.c:201 [inline]
 driver_remove_file+0x4a/0x60 drivers/base/driver.c:197
 remove_bind_files drivers/base/bus.c:605 [inline]
 bus_remove_driver+0x224/0x2c0 drivers/base/bus.c:743
 driver_unregister+0x76/0xb0 drivers/base/driver.c:277
 comedi_device_detach_locked+0x12f/0xa50 drivers/comedi/drivers.c:207
 do_devconfig_ioctl+0x555/0x710 drivers/comedi/comedi_fops.c:848
 comedi_unlocked_ioctl+0x165d/0x2f00 drivers/comedi/comedi_fops.c:2178
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb8f9f8eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb8fada4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb8fa1e6180 RCX: 00007fb8f9f8eec9
RDX: 0000000000000000 RSI: 0000000040946400 RDI: 000000000000000a
RBP: 00007fb8fa011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb8fa1e6218 R14: 00007fb8fa1e6180 R15: 00007ffed56f90f8
 </TASK>

Allocated by task 12909:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
 kasan_save_track+0x14/0x30 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __do_kmalloc_node mm/slub.c:5627 [inline]
 __kmalloc_noprof+0x32f/0x880 mm/slub.c:5639
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kmalloc_array_noprof include/linux/slab.h:1003 [inline]
 security_inode_init_security+0x13f/0x390 security/security.c:1868
 shmem_symlink+0x135/0x9f0 mm/shmem.c:4099
 vfs_symlink fs/namei.c:4817 [inline]
 vfs_symlink+0x403/0x680 fs/namei.c:4801
 do_symlinkat+0x261/0x310 fs/namei.c:4843
 __do_sys_symlinkat fs/namei.c:4859 [inline]
 __se_sys_symlinkat fs/namei.c:4856 [inline]
 __x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4856
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 12909:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
 kasan_save_track+0x14/0x30 mm/kasan/common.c:77
 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587
 kasan_save_free_info mm/kasan/kasan.h:406 [inline]
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2523 [inline]
 slab_free mm/slub.c:6611 [inline]
 kfree+0x2b8/0x6d0 mm/slub.c:6818
 security_inode_init_security+0x2eb/0x390 security/security.c:1895
 shmem_symlink+0x135/0x9f0 mm/shmem.c:4099
 vfs_symlink fs/namei.c:4817 [inline]
 vfs_symlink+0x403/0x680 fs/namei.c:4801
 do_symlinkat+0x261/0x310 fs/namei.c:4843
 __do_sys_symlinkat fs/namei.c:4859 [inline]
 __se_sys_symlinkat fs/namei.c:4856 [inline]
 __x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4856
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802b011400
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 48 bytes inside of
 freed 256-byte region [ffff88802b011400, ffff88802b011500)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2b010
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813ff26b40 ffffea0001e87300 dead000000000004
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813ff26b40 ffffea0001e87300 dead000000000004
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffea0000ac0401 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5986, tgid 5986 (syz-executor), ts 78436266836, free_ts 78408942267
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:3039 [inline]
 allocate_slab mm/slub.c:3212 [inline]
 new_slab+0x24a/0x360 mm/slub.c:3266
 ___slab_alloc+0xdc4/0x1ae0 mm/slub.c:4636
 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4755
 __slab_alloc_node mm/slub.c:4831 [inline]
 slab_alloc_node mm/slub.c:5253 [inline]
 __do_kmalloc_node mm/slub.c:5626 [inline]
 __kmalloc_noprof+0x501/0x880 mm/slub.c:5639
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kmalloc_array_noprof include/linux/slab.h:1003 [inline]
 security_inode_init_security+0x13f/0x390 security/security.c:1868
 shmem_symlink+0x135/0x9f0 mm/shmem.c:4099
 vfs_symlink fs/namei.c:4817 [inline]
 vfs_symlink+0x403/0x680 fs/namei.c:4801
 do_symlinkat+0x261/0x310 fs/namei.c:4843
 __do_sys_symlinkat fs/namei.c:4859 [inline]
 __se_sys_symlinkat fs/namei.c:4856 [inline]
 __x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4856
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5795 tgid 5795 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4955 [inline]
 slab_alloc_node mm/slub.c:5265 [inline]
 kmem_cache_alloc_node_noprof+0x28a/0x770 mm/slub.c:5317
 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:660
 alloc_skb_fclone include/linux/skbuff.h:1433 [inline]
 tcp_stream_alloc_skb+0x34/0x560 net/ipv4/tcp.c:912
 tcp_sendmsg_locked+0x12d9/0x42e0 net/ipv4/tcp.c:1218
 tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1413
 inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:853
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 sock_write_iter+0x509/0x610 net/socket.c:1195
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x7d3/0x11d0 fs/read_write.c:686
 ksys_write+0x1f8/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88802b011300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802b011380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802b011400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88802b011480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802b011500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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