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BUG: KASAN: use-after-free in dtMoveEntry fs/jfs/jfs_dtree.c:4218 [inline]
BUG: KASAN: use-after-free in dtSplitPage+0x1ac1/0x31d0 fs/jfs/jfs_dtree.c:1559
Write of size 1 at addr ffff88805db41000 by task syz.4.369/6707

CPU: 0 PID: 6707 Comm: syz.4.369 Not tainted 5.15.182-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 dtMoveEntry fs/jfs/jfs_dtree.c:4218 [inline]
 dtSplitPage+0x1ac1/0x31d0 fs/jfs/jfs_dtree.c:1559
 dtSplitUp fs/jfs/jfs_dtree.c:1090 [inline]
 dtInsert+0xf2a/0x5730 fs/jfs/jfs_dtree.c:869
 jfs_create+0x69d/0xa50 fs/jfs/namei.c:137
 lookup_open fs/namei.c:3462 [inline]
 open_last_lookups fs/namei.c:3532 [inline]
 path_openat+0x11e1/0x2f30 fs/namei.c:3739
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
 do_sys_openat2+0x142/0x4a0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_creat fs/open.c:1345 [inline]
 __se_sys_creat fs/open.c:1339 [inline]
 __x64_sys_creat+0x8c/0xb0 fs/open.c:1339
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f93c264b969
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:00007f93c0492038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f93c2873080 RCX: 00007f93c264b969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000006c0
RBP: 00007f93c26cdab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f93c2873080 R15: 00007ffc6951f468
 </TASK>

The buggy address belongs to the page:
page:ffffea000176d040 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5db41
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea000176d088 ffff8880b9040950 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x500dc0(GFP_USER|__GFP_ZERO|__GFP_ACCOUNT), pid 6700, ts 204427813198, free_ts 204464894148
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5466
 __get_free_pages+0x8/0x30 mm/page_alloc.c:5503
 mmu_memory_cache_alloc_obj virt/kvm/kvm_main.c:395 [inline]
 kvm_mmu_topup_memory_cache+0xee/0x200 virt/kvm/kvm_main.c:405
 mmu_topup_memory_caches arch/x86/kvm/mmu/mmu.c:738 [inline]
 kvm_mmu_load+0xb4/0x1b90 arch/x86/kvm/mmu/mmu.c:5067
 kvm_mmu_reload arch/x86/kvm/mmu.h:90 [inline]
 vcpu_enter_guest+0x61b3/0x70e0 arch/x86/kvm/x86.c:9899
 vcpu_run arch/x86/kvm/x86.c:10160 [inline]
 kvm_arch_vcpu_ioctl_run+0xdea/0x1f40 arch/x86/kvm/x86.c:10397
 kvm_vcpu_ioctl+0x887/0xb80 virt/kvm/kvm_main.c:3894
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x94/0x280 mm/page_alloc.c:3396
 kvm_mmu_free_memory_cache+0xd3/0x150 virt/kvm/kvm_main.c:424
 mmu_free_memory_caches arch/x86/kvm/mmu/mmu.c:755 [inline]
 kvm_mmu_destroy+0x273/0x2a0 arch/x86/kvm/mmu/mmu.c:6190
 kvm_arch_vcpu_destroy+0x19f/0x2b0 arch/x86/kvm/x86.c:11188
 kvm_vcpu_destroy+0x1d/0x90 virt/kvm/kvm_main.c:464
 kvm_free_vcpus arch/x86/kvm/x86.c:11623 [inline]
 kvm_arch_destroy_vm+0x44a/0x760 arch/x86/kvm/x86.c:11742
 kvm_destroy_vm virt/kvm/kvm_main.c:1251 [inline]
 kvm_put_kvm+0xdd7/0x17d0 virt/kvm/kvm_main.c:1283
 kvm_vm_release+0x42/0x50 virt/kvm/kvm_main.c:1306
 __fput+0x234/0x930 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff88805db40f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805db40f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805db41000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88805db41080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805db41100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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