syzbot

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BUG: KASAN: slab-use-after-free in __hlist_del include/linux/list.h:982 [inline]
BUG: KASAN: slab-use-after-free in hlist_del_init include/linux/list.h:1008 [inline]
BUG: KASAN: slab-use-after-free in binderfs_evict_inode+0x335/0x340 drivers/android/binderfs.c:277
Write of size 8 at addr ffff8880290d5c08 by task syz.1.52/5889

CPU: 0 UID: 0 PID: 5889 Comm: syz.1.52 Not tainted 6.14.0-rc6-syzkaller-00016-g0fed89a961ea #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xd9/0x110 mm/kasan/report.c:634
 __hlist_del include/linux/list.h:982 [inline]
 hlist_del_init include/linux/list.h:1008 [inline]
 binderfs_evict_inode+0x335/0x340 drivers/android/binderfs.c:277
 evict+0x409/0x960 fs/inode.c:796
 iput_final fs/inode.c:1946 [inline]
 iput fs/inode.c:1972 [inline]
 iput+0x52a/0x890 fs/inode.c:1958
 dentry_unlink_inode+0x29c/0x480 fs/dcache.c:440
 __dentry_kill+0x1d0/0x600 fs/dcache.c:643
 shrink_kill fs/dcache.c:1088 [inline]
 shrink_dentry_list+0x140/0x5d0 fs/dcache.c:1115
 shrink_dcache_parent+0xe2/0x530 fs/dcache.c:1549
 do_one_tree fs/dcache.c:1578 [inline]
 shrink_dcache_for_umount+0xa1/0x3e0 fs/dcache.c:1595
 generic_shutdown_super+0x6c/0x390 fs/super.c:620
 kill_anon_super fs/super.c:1237 [inline]
 kill_litter_super+0x70/0xa0 fs/super.c:1247
 binderfs_kill_super+0x3b/0xa0 drivers/android/binderfs.c:792
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
 deactivate_super+0xde/0x100 fs/super.c:506
 cleanup_mnt+0x222/0x450 fs/namespace.c:1413
 task_work_run+0x14e/0x250 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xad8/0x2d70 kernel/exit.c:938
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
 get_signal+0x24ed/0x26c0 kernel/signal.c:3036
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 002b:0000400000000008 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f566aba5fa0 RCX: 00007f566a98d169
RDX: 0000400000000000 RSI: 0000400000000000 RDI: 0000000000000000
RBP: 00007f566aa0e2a0 R08: 0000400000000000 R09: 0000000000000000
R10: 0000400000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f566aba5fa0 R14: 00007f566aba5fa0 R15: 0000000000000005
 </TASK>

Allocated by task 5829:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 binderfs_binder_device_create.isra.0+0x17a/0xb70 drivers/android/binderfs.c:147
 binderfs_fill_super+0x8d6/0x1360 drivers/android/binderfs.c:730
 vfs_get_super fs/super.c:1280 [inline]
 get_tree_nodev+0xda/0x190 fs/super.c:1299
 vfs_get_tree+0x8b/0x340 fs/super.c:1814
 do_new_mount fs/namespace.c:3560 [inline]
 path_mount+0x14e6/0x1f10 fs/namespace.c:3887
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount fs/namespace.c:4088 [inline]
 __x64_sys_mount+0x28f/0x310 fs/namespace.c:4088
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5829:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4609 [inline]
 kfree+0x2c4/0x4d0 mm/slub.c:4757
 binderfs_evict_inode+0x29f/0x340 drivers/android/binderfs.c:279
 evict+0x409/0x960 fs/inode.c:796
 iput_final fs/inode.c:1946 [inline]
 iput fs/inode.c:1972 [inline]
 iput+0x52a/0x890 fs/inode.c:1958
 dentry_unlink_inode+0x29c/0x480 fs/dcache.c:440
 __dentry_kill+0x1d0/0x600 fs/dcache.c:643
 shrink_kill fs/dcache.c:1088 [inline]
 shrink_dentry_list+0x140/0x5d0 fs/dcache.c:1115
 shrink_dcache_parent+0xe2/0x530 fs/dcache.c:1549
 do_one_tree fs/dcache.c:1578 [inline]
 shrink_dcache_for_umount+0xa1/0x3e0 fs/dcache.c:1595
 generic_shutdown_super+0x6c/0x390 fs/super.c:620
 kill_anon_super fs/super.c:1237 [inline]
 kill_litter_super+0x70/0xa0 fs/super.c:1247
 binderfs_kill_super+0x3b/0xa0 drivers/android/binderfs.c:792
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
 deactivate_super+0xde/0x100 fs/super.c:506
 cleanup_mnt+0x222/0x450 fs/namespace.c:1413
 task_work_run+0x14e/0x250 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xad8/0x2d70 kernel/exit.c:938
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
 get_signal+0x24ed/0x26c0 kernel/signal.c:3036
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880290d5c00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 8 bytes inside of
 freed 512-byte region [ffff8880290d5c00, ffff8880290d5e00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880290d5800 pfn:0x290d4
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b041c80 0000000000000000 dead000000000001
raw: ffff8880290d5800 000000000010000f 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b041c80 0000000000000000 dead000000000001
head: ffff8880290d5800 000000000010000f 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000a43501 ffffffffffffffff 0000000000000000
head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5222, tgid 5222 (udevadm), ts 30673243450, free_ts 30319293045
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4740
 alloc_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab mm/slub.c:2587 [inline]
 new_slab+0x23d/0x330 mm/slub.c:2640
 ___slab_alloc+0xc5d/0x1720 mm/slub.c:3826
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 __kmalloc_cache_noprof+0xfa/0x410 mm/slub.c:4320
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 kernfs_fop_open+0x28b/0xdb0 fs/kernfs/file.c:623
 do_dentry_open+0x735/0x1c40 fs/open.c:956
 vfs_open+0x82/0x3f0 fs/open.c:1086
 do_open fs/namei.c:3830 [inline]
 path_openat+0x1e88/0x2d80 fs/namei.c:3989
 do_filp_open+0x20c/0x470 fs/namei.c:4016
 do_sys_openat2+0x17a/0x1e0 fs/open.c:1428
 do_sys_open fs/open.c:1443 [inline]
 __do_sys_openat fs/open.c:1459 [inline]
 __se_sys_openat fs/open.c:1454 [inline]
 __x64_sys_openat+0x175/0x210 fs/open.c:1454
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
page last free pid 25 tgid 25 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660
 rcu_do_batch kernel/rcu/tree.c:2546 [inline]
 rcu_core+0x79d/0x14d0 kernel/rcu/tree.c:2802
 handle_softirqs+0x213/0x8f0 kernel/softirq.c:561
 run_ksoftirqd kernel/softirq.c:950 [inline]
 run_ksoftirqd+0x3a/0x60 kernel/softirq.c:942
 smpboot_thread_fn+0x661/0xa30 kernel/smpboot.c:164
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff8880290d5b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880290d5b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880290d5c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff8880290d5c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880290d5d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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