==================================================================
BUG: KASAN: use-after-free in diRead+0x94f/0xb90 fs/jfs/jfs_imap.c:329
Read of size 4 at addr ffff888051a08010 by task syz.3.367/11664

CPU: 0 UID: 0 PID: 11664 Comm: syz.3.367 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 diRead+0x94f/0xb90 fs/jfs/jfs_imap.c:329
 jfs_iget+0x89/0x470 fs/jfs/inode.c:35
 jfs_lookup+0x1c5/0x380 fs/jfs/namei.c:1469
 lookup_open fs/namei.c:4413 [inline]
 open_last_lookups fs/namei.c:4540 [inline]
 path_openat+0x13aa/0x3df0 fs/namei.c:4784
 do_filp_open+0x1fa/0x410 fs/namei.c:4814
 do_sys_openat2+0x121/0x200 fs/open.c:1430
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_openat fs/open.c:1452 [inline]
 __se_sys_openat fs/open.c:1447 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1447
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0d8786f749
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:00007f0d85aad038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f0d87ac6090 RCX: 00007f0d8786f749
RDX: 0000000000000002 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f0d878f3f91 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000001d9 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0d87ac6128 R14: 00007f0d87ac6090 R15: 00007fff67ce3d18
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888051a08000 pfn:0x51a08
flags: 0x80000000000000(node=0|zone=1)
raw: 0080000000000000 0000000000000000 dead000000000122 0000000000000000
raw: ffff888051a08000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x40dc0(GFP_KERNEL|__GFP_ZERO|__GFP_COMP), pid 11665, tgid 11656 (syz.3.367), ts 1045044805075, free_ts 1045352009769
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x234/0x290 mm/page_alloc.c:1857
 prep_new_page mm/page_alloc.c:1865 [inline]
 get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2486
 ___kmalloc_large_node+0x4e/0x150 mm/slub.c:5598
 __kmalloc_large_noprof+0x1a/0x90 mm/slub.c:5619
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 diMount+0x29/0xd80 fs/jfs/jfs_imap.c:105
 jfs_mount+0x426/0x870 fs/jfs/jfs_mount.c:176
 jfs_fill_super+0x6bc/0xd80 fs/jfs/super.c:523
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
 vfs_get_tree+0x92/0x2a0 fs/super.c:1751
 fc_mount fs/namespace.c:1199 [inline]
 do_new_mount_fc fs/namespace.c:3636 [inline]
 do_new_mount+0x302/0xa10 fs/namespace.c:3712
 do_mount fs/namespace.c:4035 [inline]
 __do_sys_mount fs/namespace.c:4224 [inline]
 __se_sys_mount+0x313/0x410 fs/namespace.c:4201
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 11658 tgid 11656 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0xfe1/0x1170 mm/page_alloc.c:2943
 diUnmount+0xff/0x130 fs/jfs/jfs_imap.c:195
 jfs_mount_rw+0x2dd/0x670 fs/jfs/jfs_mount.c:239
 jfs_reconfigure+0x5f9/0xa00 fs/jfs/super.c:409
 reconfigure_super+0x227/0x880 fs/super.c:1077
 do_remount fs/namespace.c:3264 [inline]
 path_mount+0xd29/0xff0 fs/namespace.c:4014
 do_mount fs/namespace.c:4035 [inline]
 __do_sys_mount fs/namespace.c:4224 [inline]
 __se_sys_mount+0x313/0x410 fs/namespace.c:4201
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888051a07f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888051a07f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888051a08000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                         ^
 ffff888051a08080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888051a08100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================