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BUG: KASAN: slab-out-of-bounds in ciCompare fs/jfs/jfs_dtree.c:3428 [inline]
BUG: KASAN: slab-out-of-bounds in dtSearch+0x16b4/0x21b0 fs/jfs/jfs_dtree.c:645
Read of size 1 at addr ffff88805fa403e4 by task syz.3.1016/13615

CPU: 0 UID: 0 PID: 13615 Comm: syz.3.1016 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 ciCompare fs/jfs/jfs_dtree.c:3428 [inline]
 dtSearch+0x16b4/0x21b0 fs/jfs/jfs_dtree.c:645
 jfs_lookup+0x1b0/0x420 fs/jfs/namei.c:1464
 __lookup_slow+0x2d2/0x440 fs/namei.c:1916
 lookup_slow+0x53/0x70 fs/namei.c:1933
 walk_component fs/namei.c:2279 [inline]
 lookup_last fs/namei.c:2786 [inline]
 path_lookupat+0x3f5/0x8c0 fs/namei.c:2810
 filename_lookup+0x256/0x5d0 fs/namei.c:2839
 filename_linkat+0x11a/0x600 fs/namei.c:5800
 __do_sys_link fs/namei.c:5853 [inline]
 __se_sys_link+0x55/0x2c0 fs/namei.c:5849
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb6b871c819
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:00007fb6b6976028 EFLAGS: 00000246 ORIG_RAX: 0000000000000056
RAX: ffffffffffffffda RBX: 00007fb6b8995fa0 RCX: 00007fb6b871c819
RDX: 0000000000000000 RSI: 00002000000000c0 RDI: 0000200000000080
RBP: 00007fb6b87b2c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb6b8996038 R14: 00007fb6b8995fa0 R15: 00007ffe22415268
 </TASK>

The buggy address belongs to the object at ffff88805fa40000
 which belongs to the cache romfs_i of size 1296
The buggy address is located 996 bytes inside of
 allocated 1296-byte region [ffff88805fa40000, ffff88805fa40510)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805fa45370 pfn:0x5fa40
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8880366f5a01
flags: 0x80000000000240(workingset|head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000240 ffff888140427b40 ffff88801d3f7188 ffff88801d3f7188
raw: ffff88805fa45370 000000080017000d 00000000f5000000 ffff8880366f5a01
head: 0080000000000240 ffff888140427b40 ffff88801d3f7188 ffff88801d3f7188
head: ffff88805fa45370 000000080017000d 00000000f5000000 ffff8880366f5a01
head: 0080000000000003 ffffea00017e9001 00000000ffffffff 00000000ffffffff
head: 0000000000000000 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 6188, tgid 6187 (syz.0.53), ts 123796302715, free_ts 112175601051
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3481
 new_slab mm/slub.c:3539 [inline]
 refill_objects+0x334/0x3c0 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 alloc_full_sheaf mm/slub.c:2834 [inline]
 __pcs_replace_empty_main+0x480/0x710 mm/slub.c:4626
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 kmem_cache_alloc_lru_noprof+0x433/0x680 mm/slub.c:4885
 alloc_inode+0x6a/0x1b0 fs/inode.c:347
 iget_locked+0x131/0x6a0 fs/inode.c:1480
 romfs_iget+0x175/0x750 fs/romfs/super.c:301
 romfs_fill_super+0x5c0/0x780 fs/romfs/super.c:526
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3763 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3839
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4338
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
page last free pid 5798 tgid 5798 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xfe3/0x1170 mm/page_alloc.c:2978
 __slab_free+0x24f/0x2a0 mm/slub.c:5573
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x100 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:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4873
 vm_area_dup+0x2b/0x670 mm/vma_init.c:123
 dup_mmap+0x8b7/0x1d50 mm/mmap.c:1787
 dup_mm kernel/fork.c:1531 [inline]
 copy_mm+0x13b/0x4a0 kernel/fork.c:1583
 copy_process+0x18be/0x3cd0 kernel/fork.c:2223
 kernel_clone+0x249/0x840 kernel/fork.c:2653
 __do_sys_clone kernel/fork.c:2794 [inline]
 __se_sys_clone kernel/fork.c:2778 [inline]
 __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2778
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88805fa40280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88805fa40300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88805fa40380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                       ^
 ffff88805fa40400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88805fa40480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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