loop0: detected capacity change from 0 to 32768
UFO tlock:0xffffc900028620d8
==================================================================
BUG: KASAN: use-after-free in lmWriteRecord+0x4c8/0x1aa0 fs/jfs/jfs_logmgr.c:433
Read of size 32 at addr ffff88805985fe00 by task syz.0.18/5058

CPU: 0 PID: 5058 Comm: syz.0.18 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x235/0x290 mm/kasan/generic.c:189
 memcpy+0x25/0x60 mm/kasan/shadow.c:65
 lmWriteRecord+0x4c8/0x1aa0 fs/jfs/jfs_logmgr.c:433
 lmLog+0x6f6/0xa30 fs/jfs/jfs_logmgr.c:314
 dtLog fs/jfs/jfs_txnmgr.c:1653 [inline]
 txLog fs/jfs/jfs_txnmgr.c:1401 [inline]
 txCommit+0x1c49/0x5200 fs/jfs/jfs_txnmgr.c:1265
 jfs_mkdir+0x8d5/0xad0 fs/jfs/namei.c:290
 vfs_mkdir+0x387/0x570 fs/namei.c:4073
 do_mkdirat+0x1df/0x5b0 fs/namei.c:4098
 __do_sys_mkdirat fs/namei.c:4113 [inline]
 __se_sys_mkdirat fs/namei.c:4111 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f8317574dd7
Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 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:00007f8316bd8e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f8316bd8ee0 RCX: 00007f8317574dd7
RDX: 00000000000001ff RSI: 0000200000000000 RDI: 00000000ffffff9c
RBP: 00002000000002c0 R08: 0000200000000080 R09: 0000000000000000
R10: 00002000000002c0 R11: 0000000000000246 R12: 0000200000000000
R13: 00007f8316bd8ea0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

The buggy address belongs to the page:
page:ffffea00016617c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5985f
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001660cc8 ffffea00016618c8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 4637, ts 124294946917, free_ts 124412297829
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 __page_cache_alloc+0xce/0x440 mm/filemap.c:1022
 page_cache_ra_unbounded+0x25d/0x940 mm/readahead.c:216
 do_page_cache_ra mm/readahead.c:269 [inline]
 force_page_cache_ra+0x3e5/0x440 mm/readahead.c:301
 page_cache_sync_readahead include/linux/pagemap.h:833 [inline]
 filemap_get_pages mm/filemap.c:2551 [inline]
 filemap_read+0x5de/0x2540 mm/filemap.c:2634
 blkdev_read_iter+0x11d/0x150 block/fops.c:563
 call_read_iter include/linux/fs.h:2167 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0x759/0xd60 fs/read_write.c:485
 ksys_read+0x152/0x260 fs/read_write.c:623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page_list+0x119/0x820 mm/page_alloc.c:3433
 release_pages+0x186c/0x1be0 mm/swap.c:963
 __pagevec_release+0x6d/0xe0 mm/swap.c:983
 pagevec_release include/linux/pagevec.h:81 [inline]
 truncate_inode_pages_range+0x362/0xfe0 mm/truncate.c:329
 kill_bdev block/bdev.c:77 [inline]
 blkdev_flush_mapping+0x188/0x360 block/bdev.c:659
 blkdev_put_whole block/bdev.c:690 [inline]
 blkdev_put+0x4d1/0x7d0 block/bdev.c:957
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x42d/0x4e0 fs/namespace.c:1148
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff88805985fd00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805985fd80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88805985fe00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88805985fe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805985ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================