KASAN: slab-use-after-free Read in security_inode_follow

ID	Workflow	Result	Correct	Bug	Created	Started	Finished	Revision	Error
ef1aed57-2f3a-44bb-98c9-fb2e6e02ecdb	assessment-security	DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌	❓	KASAN: slab-use-after-free Read in security_inode_follow_link	2026/05/29 23:40	2026/05/29 23:40	2026/05/30 00:35	6b4a844333e83556da95d61d7f207e7ef5cd4bc6

Title	Replies (including bot)	Last reply
[syzbot] [lsm?] KASAN: slab-use-after-free Read in security_inode_follow_link	2 (6)	2026/05/30 10:47
[PATCH] bpf: defer bpffs symlink inode freeing until RCU grace period	1 (1)	2026/05/30 01:30

Title

Replies (including bot)

Last reply

[syzbot] [lsm?] KASAN: slab-use-after-free Read in security_inode_follow_link

2 (6)

2026/05/30 10:47

[PATCH] bpf: defer bpffs symlink inode freeing until RCU grace period

1 (1)

2026/05/30 01:30

Created	Duration	User	Patch	Repo	Result
2026/05/30 09:52	44m	hdanton@sina.com	patch	upstream	log
2026/05/30 06:13	18m	hdanton@sina.com	patch	upstream	report log
2026/05/30 00:40	26m	hongao@uniontech.com	patch	upstream	OK log

Created

Duration

User

Patch

Repo

Result

2026/05/30 09:52

44m

hdanton@sina.com

patch

upstream

log

2026/05/30 06:13

18m

hdanton@sina.com

patch

upstream

report log

2026/05/30 00:40

26m

hongao@uniontech.com

patch

upstream

OK log

================================================================== BUG: KASAN: slab-use-after-free in security_inode_follow_link+0x277/0x280 security/security.c:1819 Read of size 4 at addr ffff8880393e0004 by task syz.0.594/8610 CPU: 3 UID: 0 PID: 8610 Comm: syz.0.594 Not tainted syzkaller #0 PREEMPT(full) 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+0xdf/0x1d0 mm/kasan/report.c:595 security_inode_follow_link+0x277/0x280 security/security.c:1819 pick_link+0x433/0x13c0 fs/namei.c:2049 step_into_slowpath+0x9ba/0xf90 fs/namei.c:2123 step_into fs/namei.c:2148 [inline] walk_component fs/namei.c:2284 [inline] link_path_walk+0xf28/0x1cc0 fs/namei.c:2652 path_parentat fs/namei.c:2856 [inline] __filename_parentat+0x213/0x740 fs/namei.c:2880 filename_parentat fs/namei.c:2898 [inline] filename_unlinkat+0xf7/0x730 fs/namei.c:5537 __do_sys_unlinkat fs/namei.c:5597 [inline] __se_sys_unlinkat fs/namei.c:5589 [inline] __x64_sys_unlinkat+0xc0/0x130 fs/namei.c:5589 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f60b0f9ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f60b1dc9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 00007f60b1215fa0 RCX: 00007f60b0f9ce59 RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000000000000006 RBP: 00007f60b1032d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f60b1216038 R14: 00007f60b1215fa0 R15: 00007ffddfc81a28 </TASK> Allocated by task 8610: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4570 [inline] slab_alloc_node mm/slub.c:4899 [inline] kmem_cache_alloc_lru_noprof+0x246/0x6e0 mm/slub.c:4918 alloc_inode+0x183/0x250 fs/inode.c:347 new_inode+0x22/0x1c0 fs/inode.c:1179 bpf_get_inode kernel/bpf/inode.c:117 [inline] bpf_get_inode kernel/bpf/inode.c:102 [inline] bpf_symlink+0x69/0x240 kernel/bpf/inode.c:391 vfs_symlink fs/namei.c:5643 [inline] vfs_symlink+0x178/0x4d0 fs/namei.c:5622 filename_symlinkat+0x2a6/0x560 fs/namei.c:5668 __do_sys_symlinkat fs/namei.c:5688 [inline] __se_sys_symlinkat fs/namei.c:5683 [inline] __x64_sys_symlinkat+0x9c/0xe0 fs/namei.c:5683 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8611: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6251 [inline] kmem_cache_free+0x127/0x6c0 mm/slub.c:6378 destroy_inode+0xcb/0x1c0 fs/inode.c:394 evict+0x599/0xad0 fs/inode.c:865 iput_final fs/inode.c:1960 [inline] iput.part.0+0x605/0xf50 fs/inode.c:2009 iput+0x35/0x40 fs/inode.c:1975 filename_unlinkat+0x466/0x730 fs/namei.c:5572 __do_sys_unlinkat fs/namei.c:5597 [inline] __se_sys_unlinkat fs/namei.c:5589 [inline] __x64_sys_unlinkat+0xc0/0x130 fs/namei.c:5589 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880393e0000 which belongs to the cache inode_cache of size 1088 The buggy address is located 4 bytes inside of freed 1088-byte region [ffff8880393e0000, ffff8880393e0440) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x393e0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88803ce9f201 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff888100090000 dead000000000100 dead000000000122 raw: 0000000000000000 00000008001a001a 00000000f5000000 ffff88803ce9f201 head: 00fff00000000040 ffff888100090000 dead000000000100 dead000000000122 head: 0000000000000000 00000008001a001a 00000000f5000000 ffff88803ce9f201 head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd20d0(__GFP_RECLAIMABLE|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5753, tgid 5753 (syz-execprog), ts 103858448509, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1853 prep_new_page mm/page_alloc.c:1861 [inline] get_page_from_freelist+0x11a6/0x3410 mm/page_alloc.c:3941 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5221 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab mm/slub.c:3467 [inline] new_slab+0xa6/0x6c0 mm/slub.c:3525 refill_objects+0x277/0x420 mm/slub.c:7272 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4652 alloc_from_pcs mm/slub.c:4750 [inline] slab_alloc_node mm/slub.c:4884 [inline] kmem_cache_alloc_lru_noprof+0x485/0x6e0 mm/slub.c:4918 alloc_inode+0x183/0x250 fs/inode.c:347 iget_locked+0x1d9/0x6d0 fs/inode.c:1474 kernfs_get_inode+0x46/0x470 fs/kernfs/inode.c:252 kernfs_iop_lookup+0x1a7/0x2d0 fs/kernfs/dir.c:1274 lookup_open.isra.0+0x631/0x11b0 fs/namei.c:4484 open_last_lookups fs/namei.c:4611 [inline] path_openat+0xa98/0x31a0 fs/namei.c:4855 do_file_open+0x20e/0x430 fs/namei.c:4887 do_sys_openat2+0x10d/0x1e0 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1381 page_owner free stack trace missing Memory state around the buggy address: ffff8880393dff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880393dff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880393e0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880393e0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880393e0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================

Crashes (1):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2026/05/28 21:22	upstream	eb3f4b7426cf	9a5a7e5e	.config	console log	report	syz / log	C		[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	KASAN: slab-use-after-free Read in security_inode_follow_link

Crashes (1):

Assets (help?)