================================================================== 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 ffff88802bb90808 by task syz-executor/6026 CPU: 1 UID: 0 PID: 6026 Comm: syz-executor Not tainted 6.13.0-rc7-next-20250115-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 hlist_add_head include/linux/list.h:1026 [inline] binder_add_device+0x5f/0xa0 drivers/android/binder.c:6932 binderfs_binder_device_create+0x7bf/0x9c0 drivers/android/binderfs.c:210 binderfs_fill_super+0x944/0xd90 drivers/android/binderfs.c:729 vfs_get_super fs/super.c:1280 [inline] get_tree_nodev+0xb7/0x140 fs/super.c:1299 vfs_get_tree+0x90/0x2b0 fs/super.c:1814 do_new_mount+0x2be/0xb40 fs/namespace.c:3560 do_mount fs/namespace.c:3900 [inline] __do_sys_mount fs/namespace.c:4111 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe60f7874ca Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ffe539a5438 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fe60f801ecb RCX: 00007fe60f7874ca RDX: 00007fe60f80ec27 RSI: 00007fe60f801ecb RDI: 00007fe60f80ec27 RBP: 00007fe60f8020c3 R08: 0000000000000000 R09: 00007ffe539a54e0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe60f7e41c8 R13: 00007fe60f7e41a8 R14: 0000000000000009 R15: 0000000000000000 Allocated by task 5837: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4325 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] binderfs_binder_device_create+0x16c/0x9c0 drivers/android/binderfs.c:147 binderfs_fill_super+0x944/0xd90 drivers/android/binderfs.c:729 vfs_get_super fs/super.c:1280 [inline] get_tree_nodev+0xb7/0x140 fs/super.c:1299 vfs_get_tree+0x90/0x2b0 fs/super.c:1814 do_new_mount+0x2be/0xb40 fs/namespace.c:3560 do_mount fs/namespace.c:3900 [inline] __do_sys_mount fs/namespace.c:4111 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5837: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 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+0x196/0x430 mm/slub.c:4757 evict+0x4e8/0x9a0 fs/inode.c:796 __dentry_kill+0x20d/0x630 fs/dcache.c:625 shrink_kill+0xa9/0x2c0 fs/dcache.c:1070 shrink_dentry_list+0x2c0/0x5b0 fs/dcache.c:1097 shrink_dcache_parent+0xcb/0x3b0 do_one_tree+0x23/0xe0 fs/dcache.c:1560 shrink_dcache_for_umount+0xb4/0x180 fs/dcache.c:1577 generic_shutdown_super+0x6a/0x2d0 fs/super.c:620 kill_anon_super fs/super.c:1237 [inline] kill_litter_super+0x76/0xb0 fs/super.c:1247 binderfs_kill_super+0x44/0x90 drivers/android/binderfs.c:791 deactivate_locked_super+0xc4/0x130 fs/super.c:473 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1413 task_work_run+0x24f/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2a/0x28e0 kernel/exit.c:938 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x16b2/0x1750 kernel/signal.c:3017 arch_do_signal_or_restart+0x96/0x860 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+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802bb90800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 8 bytes inside of freed 512-byte region [ffff88802bb90800, ffff88802bb90a00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88802bb91000 pfn:0x2bb90 head: order:2 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 ffff88801ac41c80 ffffea0000d06800 dead000000000002 raw: ffff88802bb91000 000000000010000f 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801ac41c80 ffffea0000d06800 dead000000000002 head: ffff88802bb91000 000000000010000f 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0000aee401 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 5226, tgid 5226 (udevadm), ts 21185795300, free_ts 21172921902 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab+0x8f/0x3a0 mm/slub.c:2587 new_slab mm/slub.c:2640 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826 __slab_alloc+0x58/0xa0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] __kmalloc_cache_noprof+0x27b/0x390 mm/slub.c:4320 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] kernfs_fop_open+0x3e0/0xd10 fs/kernfs/file.c:623 do_dentry_open+0xdec/0x1960 fs/open.c:955 vfs_open+0x3b/0x370 fs/open.c:1085 do_open fs/namei.c:3828 [inline] path_openat+0x2c74/0x3580 fs/namei.c:3987 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1427 do_sys_open fs/open.c:1442 [inline] __do_sys_openat fs/open.c:1458 [inline] __se_sys_openat fs/open.c:1453 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1453 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 page last free pid 5223 tgid 5223 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660 discard_slab mm/slub.c:2684 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3153 put_cpu_partial+0x17c/0x250 mm/slub.c:3228 __slab_free+0x290/0x380 mm/slub.c:4479 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4171 getname_flags+0xb7/0x540 fs/namei.c:139 do_readlinkat+0xd8/0x3a0 fs/stat.c:561 __do_sys_readlink fs/stat.c:599 [inline] __se_sys_readlink fs/stat.c:596 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:596 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88802bb90700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802bb90780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802bb90800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802bb90880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802bb90900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================