================================================================== BUG: KASAN: slab-use-after-free in dtMoveEntry fs/jfs/jfs_dtree.c:3931 [inline] BUG: KASAN: slab-use-after-free in dtSplitPage+0x1bce/0x36a0 fs/jfs/jfs_dtree.c:1558 Write of size 1 at addr ffff88807af44000 by task syz.2.1238/12213 CPU: 0 UID: 0 PID: 12213 Comm: syz.2.1238 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 dtMoveEntry fs/jfs/jfs_dtree.c:3931 [inline] dtSplitPage+0x1bce/0x36a0 fs/jfs/jfs_dtree.c:1558 dtSplitUp fs/jfs/jfs_dtree.c:1089 [inline] dtInsert+0x1080/0x5cb0 fs/jfs/jfs_dtree.c:868 jfs_mkdir+0x76b/0xb00 fs/jfs/namei.c:271 vfs_mkdir+0x406/0x620 fs/namei.c:5276 filename_mkdirat+0x285/0x510 fs/namei.c:5309 __do_sys_mkdirat fs/namei.c:5330 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5327 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f458b59cd07 Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 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:00007f458c40be58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f458c40bee0 RCX: 00007f458b59cd07 RDX: 00000000000001ff RSI: 0000200000000580 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000580 R13: 00007f458c40bea0 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 9078: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4612 [inline] slab_alloc_node mm/slub.c:4945 [inline] kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4959 alloc_posix_timer kernel/time/posix-timers.c:430 [inline] do_timer_create+0x247/0x1100 kernel/time/posix-timers.c:488 __do_sys_timer_create kernel/time/posix-timers.c:583 [inline] __se_sys_timer_create kernel/time/posix-timers.c:574 [inline] __x64_sys_timer_create+0x169/0x1c0 kernel/time/posix-timers.c:574 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 12046: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2705 [inline] __rcu_free_sheaf_prepare+0x12d/0x2a0 mm/slub.c:2956 rcu_free_sheaf+0x31/0x200 mm/slub.c:6004 rcu_do_batch kernel/rcu/tree.c:2645 [inline] rcu_core+0x78b/0x10a0 kernel/rcu/tree.c:2897 handle_softirqs+0x225/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 The buggy address belongs to the object at ffff88807af44000 which belongs to the cache posix_timers_cache of size 448 The buggy address is located 0 bytes inside of freed 448-byte region [ffff88807af44000, ffff88807af441c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807af45000 pfn:0x7af44 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888033235e01 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801dedf140 ffffea0001db2890 ffffea0001f08f90 raw: ffff88807af45000 0000000800100009 00000000f5000000 ffff888033235e01 head: 00fff00000000240 ffff88801dedf140 ffffea0001db2890 ffffea0001f08f90 head: ffff88807af45000 0000000800100009 00000000f5000000 ffff888033235e01 head: 00fff00000000001 ffffffffffffff81 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5885, tgid 5884 (syz.1.10), ts 103750024808, free_ts 103698959035 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x21fa/0x2270 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3294 [inline] allocate_slab+0x79/0x5e0 mm/slub.c:3408 new_slab mm/slub.c:3454 [inline] refill_objects+0x2d5/0x350 mm/slub.c:7338 refill_sheaf mm/slub.c:2832 [inline] __pcs_replace_empty_main+0x2bf/0x6b0 mm/slub.c:4703 alloc_from_pcs mm/slub.c:4801 [inline] slab_alloc_node mm/slub.c:4933 [inline] kmem_cache_alloc_noprof+0x382/0x5f0 mm/slub.c:4959 alloc_posix_timer kernel/time/posix-timers.c:430 [inline] do_timer_create+0x247/0x1100 kernel/time/posix-timers.c:488 __do_sys_timer_create kernel/time/posix-timers.c:583 [inline] __se_sys_timer_create kernel/time/posix-timers.c:574 [inline] __x64_sys_timer_create+0x169/0x1c0 kernel/time/posix-timers.c:574 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5755 tgid 5755 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950 __slab_free+0x274/0x2c0 mm/slub.c:5767 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4612 [inline] slab_alloc_node mm/slub.c:4945 [inline] kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4959 alloc_filename fs/namei.c:147 [inline] do_getname+0x2e/0x250 fs/namei.c:187 class_filename_flags_constructor include/linux/fs.h:2566 [inline] do_sys_openat2+0xcc/0x200 fs/open.c:1367 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807af43f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807af43f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88807af44000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807af44080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807af44100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================