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BUG: KASAN: slab-out-of-bounds in dtSplitPage+0x10d4/0x31d0 fs/jfs/jfs_dtree.c:-1
Read of size 1 at addr ffff8880547840b5 by task syz.6.721/7613

CPU: 1 PID: 7613 Comm: syz.6.721 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:420
 kasan_report+0x10b/0x140 mm/kasan/report.c:524
 dtSplitPage+0x10d4/0x31d0 fs/jfs/jfs_dtree.c:-1
 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
 dtInsert+0xfbd/0x58a0 fs/jfs/jfs_dtree.c:871
 jfs_mkdir+0x6e5/0xa70 fs/jfs/namei.c:270
 vfs_mkdir+0x387/0x570 fs/namei.c:4106
 do_mkdirat+0x1d0/0x430 fs/namei.c:4131
 __do_sys_mkdirat fs/namei.c:4146 [inline]
 __se_sys_mkdirat fs/namei.c:4144 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4144
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6bb0d8d457
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 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:00007f6bb1c7ee68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f6bb1c7eef0 RCX: 00007f6bb0d8d457
RDX: 00000000000001ff RSI: 00002000000000c0 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000000c0
R13: 00007f6bb1c7eeb0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 7581:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737
 slab_alloc_node mm/slub.c:3398 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc_lru+0x11a/0x2e0 mm/slub.c:3429
 alloc_inode_sb include/linux/fs.h:3245 [inline]
 jfs_alloc_inode+0x24/0x60 fs/jfs/super.c:105
 alloc_inode fs/inode.c:261 [inline]
 iget_locked+0x1a9/0x830 fs/inode.c:1373
 jfs_iget+0x20/0x3c0 fs/jfs/inode.c:29
 jfs_lookup+0x1c2/0x380 fs/jfs/namei.c:1467
 __lookup_slow+0x27d/0x3a0 fs/namei.c:1690
 lookup_slow+0x53/0x70 fs/namei.c:1707
 walk_component+0x2be/0x3f0 fs/namei.c:1998
 lookup_last fs/namei.c:2455 [inline]
 path_lookupat+0x169/0x440 fs/namei.c:2479
 filename_lookup+0x1f0/0x500 fs/namei.c:2508
 user_path_at_empty+0x3e/0x60 fs/namei.c:2905
 user_path_at include/linux/namei.h:57 [inline]
 __do_sys_chdir fs/open.c:514 [inline]
 __se_sys_chdir+0x91/0x280 fs/open.c:508
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff888054783780
 which belongs to the cache jfs_ip of size 2240
The buggy address is located 117 bytes to the right of
 2240-byte region [ffff888054783780, ffff888054784040)

The buggy address belongs to the physical page:
page:ffffea000151e000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x54780
head:ffffea000151e000 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff888062419401
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888146ed8dc0
raw: 0000000000000000 00000000800d000d 00000001ffffffff ffff888062419401
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0x1d2050(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 5596, tgid 5595 (syz.4.246), ts 179154709220, free_ts 12187106453
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328
 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
 alloc_slab_page+0x5d/0x160 mm/slub.c:1794
 allocate_slab mm/slub.c:1939 [inline]
 new_slab+0x87/0x2c0 mm/slub.c:1992
 ___slab_alloc+0xbc6/0x1220 mm/slub.c:3180
 __slab_alloc mm/slub.c:3279 [inline]
 slab_alloc_node mm/slub.c:3364 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc_lru+0x1ae/0x2e0 mm/slub.c:3429
 alloc_inode_sb include/linux/fs.h:3245 [inline]
 jfs_alloc_inode+0x24/0x60 fs/jfs/super.c:105
 alloc_inode fs/inode.c:261 [inline]
 new_inode_pseudo+0x5f/0x1c0 fs/inode.c:1063
 new_inode+0x25/0x1c0 fs/inode.c:1091
 jfs_fill_super+0x392/0xac0 fs/jfs/super.c:544
 mount_bdev+0x287/0x3c0 fs/super.c:1443
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:632
 vfs_get_tree+0x88/0x270 fs/super.c:1573
 do_new_mount+0x24a/0xa40 fs/namespace.c:3069
 do_mount fs/namespace.c:3412 [inline]
 __do_sys_mount fs/namespace.c:3620 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3597
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1459 [inline]
 free_pcp_prepare mm/page_alloc.c:1509 [inline]
 free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479
 free_contig_range+0x9d/0x150 mm/page_alloc.c:9574
 destroy_args+0x100/0xa31 mm/debug_vm_pgtable.c:1031
 debug_vm_pgtable+0x32a/0x37e mm/debug_vm_pgtable.c:1359
 do_one_initcall+0x214/0x7a0 init/main.c:1298
 do_initcall_level+0x137/0x1e4 init/main.c:1371
 do_initcalls+0x4b/0x8a init/main.c:1387
 kernel_init_freeable+0x3fa/0x5ac init/main.c:1626
 kernel_init+0x19/0x1b0 init/main.c:1514
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Memory state around the buggy address:
 ffff888054783f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888054784000: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff888054784080: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
                                     ^
 ffff888054784100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888054784180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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