==================================================================
BUG: KASAN: slab-out-of-bounds in dtInsertEntry+0xd74/0x1270 fs/jfs/jfs_dtree.c:3753
Read of size 4 at addr ffff8880702d6e8c by task syz.6.1244/7959

CPU: 1 PID: 7959 Comm: syz.6.1244 Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0xa8/0x200 mm/kasan/report.c:418
 kasan_report+0x10b/0x140 mm/kasan/report.c:522
 dtInsertEntry+0xd74/0x1270 fs/jfs/jfs_dtree.c:3753
 dtSplitPage+0x24f2/0x31d0 fs/jfs/jfs_dtree.c:1596
 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
 dtInsert+0xfbd/0x58a0 fs/jfs/jfs_dtree.c:871
 jfs_mknod+0x622/0x930 fs/jfs/namei.c:1408
 vfs_mknod+0x424/0x4c0 fs/namei.c:3985
 do_mknodat+0x34e/0x4c0 fs/namei.c:-1
 __do_sys_mknod fs/namei.c:4068 [inline]
 __se_sys_mknod fs/namei.c:4066 [inline]
 __x64_sys_mknod+0x8a/0xa0 fs/namei.c:4066
 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: 0033:0x7f6c30b8e9a9
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:00007f6c319da038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007f6c30db6080 RCX: 00007f6c30b8e9a9
RDX: 000000000000070d RSI: 0000000000002000 RDI: 0000200000000780
RBP: 00007f6c30c10d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f6c30db6080 R15: 00007ffccd35b978
 </TASK>

Allocated by task 7939:
 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 ffff8880702d65c0
 which belongs to the cache jfs_ip of size 2240
The buggy address is located 12 bytes to the right of
 2240-byte region [ffff8880702d65c0, ffff8880702d6e80)

The buggy address belongs to the physical page:
page:ffffea0001c0b400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x702d0
head:ffffea0001c0b400 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff88807ac2a501
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888146aaa640
raw: 0000000000000000 00000000000d000d 00000001ffffffff ffff88807ac2a501
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 7916, tgid 7915 (syz.8.1233), ts 257989026644, free_ts 254202505803
 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
 diReadSpecial+0x4e/0x6f0 fs/jfs/jfs_imap.c:426
 jfs_mount+0x3cd/0x860 fs/jfs/jfs_mount.c:166
 jfs_fill_super+0x4de/0xac0 fs/jfs/super.c:556
 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
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
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:305
 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+0x123/0x2f0 mm/slub.c:3422
 getname_kernel+0x56/0x2f0 fs/namei.c:227
 kern_path_locked+0x7f/0x290 fs/namei.c:2596
 handle_remove drivers/base/devtmpfs.c:323 [inline]
 handle drivers/base/devtmpfs.c:393 [inline]
 devtmpfs_work_loop+0x240/0xd00 drivers/base/devtmpfs.c:406
 devtmpfsd+0x44/0x50 drivers/base/devtmpfs.c:448
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Memory state around the buggy address:
 ffff8880702d6d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880702d6e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880702d6e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff8880702d6f00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880702d6f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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