Kernel bug: KASAN: slab-use-after-free Write in dtSplitPage
Subsystem: jfs
Status: open

Crash report:
==================================================================
BUG: KASAN: slab-use-after-free in dtMoveEntry fs/jfs/jfs_dtree.c:3922 [inline]
BUG: KASAN: slab-use-after-free in dtSplitPage+0x1e37/0x3b20 fs/jfs/jfs_dtree.c:1561
Write of size 1 at addr ffff888030d3a000 by task syz-executor423/5910

CPU: 0 UID: 0 PID: 5910 Comm: syz-executor423 Not tainted 6.15.0-rc6-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xb4/0x290 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 dtMoveEntry fs/jfs/jfs_dtree.c:3922 [inline]
 dtSplitPage+0x1e37/0x3b20 fs/jfs/jfs_dtree.c:1561
 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
 dtInsert+0x109b/0x5f40 fs/jfs/jfs_dtree.c:871
 jfs_create+0x6c8/0xa80 fs/jfs/namei.c:137
 lookup_open fs/namei.c:3701 [inline]
 open_last_lookups fs/namei.c:3800 [inline]
 path_openat+0x14f1/0x3830 fs/namei.c:4036
 do_filp_open+0x1fa/0x410 fs/namei.c:4066
 do_sys_openat2+0x121/0x1c0 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_creat fs/open.c:1522 [inline]
 __se_sys_creat fs/open.c:1516 [inline]
 __x64_sys_creat+0x8f/0xc0 fs/open.c:1516
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa01cd47769
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 1f 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa01c4cc168 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007fa01cdcf6f8 RCX: 00007fa01cd47769
RDX: ffffffffffffffb0 RSI: 0000000000000000 RDI: 00002000000006c0
RBP: 00007fa01cdcf6f0 R08: 00007fa01c4cc6c0 R09: 0000000000000000
R10: 00007fa01c4cc6c0 R11: 0000000000000246 R12: 00007fa01cdcf6fc
R13: 000000000000006e R14: 00007fffbd99d4c0 R15: 00007fffbd99d5a8
 </TASK>

Allocated by task 5843:
 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]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
 tomoyo_encode+0x28b/0x550 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x58d/0x5d0 security/tomoyo/realpath.c:283
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x1c1/0x3b0 security/tomoyo/file.c:771
 security_file_open+0xb1/0x270 security/security.c:3114
 do_dentry_open+0x35e/0x1970 fs/open.c:933
 vfs_open+0x3b/0x340 fs/open.c:1086
 do_open fs/namei.c:3880 [inline]
 path_openat+0x2ee5/0x3830 fs/namei.c:4039
 do_filp_open+0x1fa/0x410 fs/namei.c:4066
 do_sys_openat2+0x121/0x1c0 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_openat fs/open.c:1460 [inline]
 __se_sys_openat fs/open.c:1455 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1455
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5843:
 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+0x193/0x440 mm/slub.c:4841
 tomoyo_check_open_permission+0x2c2/0x3b0 security/tomoyo/file.c:786
 security_file_open+0xb1/0x270 security/security.c:3114
 do_dentry_open+0x35e/0x1970 fs/open.c:933
 vfs_open+0x3b/0x340 fs/open.c:1086
 do_open fs/namei.c:3880 [inline]
 path_openat+0x2ee5/0x3830 fs/namei.c:4039
 do_filp_open+0x1fa/0x410 fs/namei.c:4066
 do_sys_openat2+0x121/0x1c0 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_openat fs/open.c:1460 [inline]
 __se_sys_openat fs/open.c:1455 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1455
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888030d3a000
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 0 bytes inside of
 freed 64-byte region [ffff888030d3a000, ffff888030d3a040)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x30d3a
ksm flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801a0418c0 ffffea00006fb7c0 0000000000000003
raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5598, tgid 5598 (dhcpcd-run-hook), ts 57932261398, free_ts 45933889478
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1718
 prep_new_page mm/page_alloc.c:1726 [inline]
 get_page_from_freelist+0x21c7/0x22a0 mm/page_alloc.c:3688
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
 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]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_noprof+0x305/0x4f0 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 ext4_htree_store_dirent+0x83/0x620 fs/ext4/dir.c:482
 htree_dirblock_to_tree+0x824/0xdf0 fs/ext4/namei.c:1111
 ext4_htree_fill_tree+0x5d7/0x10f0 fs/ext4/namei.c:1190
 ext4_dx_readdir fs/ext4/dir.c:601 [inline]
 ext4_readdir+0x2dde/0x3b60 fs/ext4/dir.c:146
 iterate_dir+0x5ac/0x770 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:403 [inline]
 __se_sys_getdents64+0xe4/0x260 fs/readdir.c:389
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5194 tgid 5194 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1262 [inline]
 __free_frozen_pages+0xb05/0xcd0 mm/page_alloc.c:2725
 mm_free_pgd kernel/fork.c:793 [inline]
 __mmdrop+0xb5/0x460 kernel/fork.c:939
 mmdrop include/linux/sched/mm.h:55 [inline]
 mmdrop_sched include/linux/sched/mm.h:83 [inline]
 mmdrop_lazy_tlb_sched include/linux/sched/mm.h:110 [inline]
 finish_task_switch+0x3ee/0x950 kernel/sched/core.c:5275
 context_switch kernel/sched/core.c:5385 [inline]
 __schedule+0x1697/0x4c70 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 schedule_hrtimeout_range_clock+0x13c/0x2f0 kernel/time/sleep_timeout.c:216
 ep_poll fs/eventpoll.c:2115 [inline]
 do_epoll_wait+0xcac/0xf30 fs/eventpoll.c:2531
 __do_sys_epoll_wait fs/eventpoll.c:2539 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2534 [inline]
 __x64_sys_epoll_wait+0x1be/0x210 fs/eventpoll.c:2534
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888030d39f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888030d39f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888030d3a000: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff888030d3a080: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888030d3a100: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================