================================================================== BUG: KASAN: slab-use-after-free in hlist_add_head include/linux/list.h:1026 [inline] BUG: KASAN: slab-use-after-free in binder_add_device+0x5f/0xa0 drivers/android/binder.c:6932 Write of size 8 at addr ffff88805728a408 by task syz.2.86/6353 CPU: 1 UID: 0 PID: 6353 Comm: syz.2.86 Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 hlist_add_head include/linux/list.h:1026 [inline] binder_add_device+0x5f/0xa0 drivers/android/binder.c:6932 binderfs_binder_device_create+0x9e7/0xc40 drivers/android/binderfs.c:210 binderfs_fill_super+0xa0e/0xe90 drivers/android/binderfs.c:730 vfs_get_super fs/super.c:1323 [inline] get_tree_nodev+0xb8/0x150 fs/super.c:1342 vfs_get_tree+0x92/0x2b0 fs/super.c:1802 vfs_cmd_create+0xa2/0x200 fs/fsopen.c:225 __do_sys_fsconfig fs/fsopen.c:467 [inline] __se_sys_fsconfig+0x78e/0x8d0 fs/fsopen.c:344 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6b4098e969 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:00007f6b417e3038 EFLAGS: 00000246 ORIG_RAX: 00000000000001af RAX: ffffffffffffffda RBX: 00007f6b40bb5fa0 RCX: 00007f6b4098e969 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000009 RBP: 00007f6b40a10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6b40bb5fa0 R15: 00007fff2cef94e8 Allocated by task 5823: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4358 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] binderfs_binder_device_create+0x1eb/0xc40 drivers/android/binderfs.c:147 binderfs_fill_super+0xa0e/0xe90 drivers/android/binderfs.c:730 vfs_get_super fs/super.c:1323 [inline] get_tree_nodev+0xb8/0x150 fs/super.c:1342 vfs_get_tree+0x92/0x2b0 fs/super.c:1802 do_new_mount+0x24a/0xa40 fs/namespace.c:3856 do_mount fs/namespace.c:4193 [inline] __do_sys_mount fs/namespace.c:4404 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5883: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x18e/0x440 mm/slub.c:4841 binder_free_proc drivers/android/binder.c:5248 [inline] binder_proc_dec_tmpref+0x228/0x4f0 drivers/android/binder.c:1565 binder_deferred_release drivers/android/binder.c:6292 [inline] binder_deferred_func+0x13a5/0x1520 drivers/android/binder.c:6319 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88805728a400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 8 bytes inside of freed 512-byte region [ffff88805728a400, ffff88805728a600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888057288800 pfn:0x57288 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801a441c80 ffffea00015ddf10 ffffea0000c79e10 raw: ffff888057288800 000000000010000d 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801a441c80 ffffea00015ddf10 ffffea0000c79e10 head: ffff888057288800 000000000010000d 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea00015ca201 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 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 5826, tgid 5826 (syz-executor), ts 107773051518, free_ts 30581217772 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21d5/0x22b0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2450 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2618 new_slab mm/slub.c:2672 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858 __slab_alloc mm/slub.c:3948 [inline] __slab_alloc_node mm/slub.c:4023 [inline] slab_alloc_node mm/slub.c:4184 [inline] __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4353 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] cpuacct_css_alloc+0x55/0x130 kernel/sched/cpuacct.c:62 css_create kernel/cgroup/cgroup.c:5664 [inline] cgroup_apply_control_enable+0x3d4/0xa80 kernel/cgroup/cgroup.c:3284 cgroup_mkdir+0xc40/0xe60 kernel/cgroup/cgroup.c:5888 kernfs_iop_mkdir+0x20e/0x350 fs/kernfs/dir.c:1268 vfs_mkdir+0x306/0x510 fs/namei.c:4366 do_mkdirat+0x247/0x590 fs/namei.c:4399 __do_sys_mkdirat fs/namei.c:4416 [inline] __se_sys_mkdirat fs/namei.c:4414 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4414 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc65/0xe60 mm/page_alloc.c:2706 __free_pages mm/page_alloc.c:5071 [inline] free_contig_range+0x1bd/0x4a0 mm/page_alloc.c:6927 destroy_args+0x7e/0x5d0 mm/debug_vm_pgtable.c:1009 debug_vm_pgtable+0x412/0x450 mm/debug_vm_pgtable.c:1389 do_one_initcall+0x233/0x820 init/main.c:1273 do_initcall_level+0x137/0x1f0 init/main.c:1335 do_initcalls+0x69/0xd0 init/main.c:1351 kernel_init_freeable+0x3d9/0x570 init/main.c:1583 kernel_init+0x1d/0x1d0 init/main.c:1473 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88805728a300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805728a380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805728a400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805728a480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805728a500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================