==================================================================
BUG: KASAN: slab-out-of-bounds in dtInsertEntry+0xe9a/0x1430 fs/jfs/jfs_dtree.c:3765
Read of size 4 at addr ffff88804796ad4c by task syz.0.0/5325

CPU: 0 UID: 0 PID: 5325 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
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
 dtInsertEntry+0xe9a/0x1430 fs/jfs/jfs_dtree.c:3765
 dtSplitPage+0x290b/0x37c0 fs/jfs/jfs_dtree.c:1596
 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
 dtInsert+0x10a4/0x5f10 fs/jfs/jfs_dtree.c:871
 jfs_create+0x75b/0xb10 fs/jfs/namei.c:138
 lookup_open fs/namei.c:4483 [inline]
 open_last_lookups fs/namei.c:4583 [inline]
 path_openat+0x1395/0x3860 fs/namei.c:4827
 do_file_open+0x23e/0x4a0 fs/namei.c:4859
 file_open_name fs/open.c:1324 [inline]
 filp_open+0x16d/0x1d0 fs/open.c:1341
 coredump_file fs/coredump.c:932 [inline]
 do_coredump fs/coredump.c:1100 [inline]
 vfs_coredump+0x2248/0x4280 fs/coredump.c:1201
 get_signal+0x1107/0x1330 kernel/signal.c:3019
 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 ret_from_fork+0x59d/0xb90 arch/x86/kernel/process.c:167
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 5317:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4501 [inline]
 slab_alloc_node mm/slub.c:4830 [inline]
 kmem_cache_alloc_lru_noprof+0x2b8/0x640 mm/slub.c:4849
 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105
 alloc_inode+0x6a/0x1b0 fs/inode.c:347
 iget_locked+0x131/0x6a0 fs/inode.c:1480
 jfs_iget+0x24/0x470 fs/jfs/inode.c:29
 jfs_lookup+0x220/0x420 fs/jfs/namei.c:1472
 __lookup_slow+0x2b7/0x410 fs/namei.c:1916
 lookup_slow+0x53/0x70 fs/namei.c:1933
 walk_component fs/namei.c:2279 [inline]
 link_path_walk+0xd1e/0x18d0 fs/namei.c:2647
 path_parentat fs/namei.c:2851 [inline]
 __filename_parentat+0x27f/0x6f0 fs/namei.c:2875
 filename_parentat fs/namei.c:2893 [inline]
 filename_renameat2+0x22d/0x9c0 fs/namei.c:6090
 __do_sys_renameat2 fs/namei.c:6173 [inline]
 __se_sys_renameat2+0x5a/0x2c0 fs/namei.c:6168
 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

The buggy address belongs to the object at ffff88804796a4a0
 which belongs to the cache jfs_ip of size 2216
The buggy address is located 4 bytes to the right of
 allocated 2216-byte region [ffff88804796a4a0, ffff88804796ad48)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88804796ede0 pfn:0x47968
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88804796f709
flags: 0x4fff00000000240(workingset|head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000240 ffff888000de3b40 ffff8880316dc048 ffff8880316dc048
raw: ffff88804796ede0 00000008000d000c 00000000f5000000 ffff88804796f709
head: 04fff00000000240 ffff888000de3b40 ffff8880316dc048 ffff8880316dc048
head: ffff88804796ede0 00000008000d000c 00000000f5000000 ffff88804796f709
head: 04fff00000000003 ffffea00011e5a01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 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 0xd2050(__GFP_RECLAIMABLE|__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5317, tgid 5316 (syz.0.0), ts 84879798290, free_ts 0
 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+0x24dc/0x2580 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3255 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3444
 new_slab mm/slub.c:3502 [inline]
 refill_objects+0x331/0x3c0 mm/slub.c:7134
 refill_sheaf+0x29/0x50 mm/slub.c:2804
 alloc_full_sheaf mm/slub.c:2825 [inline]
 __pcs_replace_empty_main+0x3ef/0x620 mm/slub.c:4588
 alloc_from_pcs mm/slub.c:4681 [inline]
 slab_alloc_node mm/slub.c:4815 [inline]
 kmem_cache_alloc_lru_noprof+0x37c/0x640 mm/slub.c:4849
 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105
 alloc_inode+0x6a/0x1b0 fs/inode.c:347
 new_inode+0x22/0x170 fs/inode.c:1185
 jfs_fill_super+0x569/0xd80 fs/jfs/super.c:511
 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:3760 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3836
 do_mount fs/namespace.c:4159 [inline]
 __do_sys_mount fs/namespace.c:4348 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4325
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88804796ac00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88804796ac80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88804796ad00: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
                                              ^
 ffff88804796ad80: fc fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00
 ffff88804796ae00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================