KASAN: slab-use-after-free Read in jfs_strfromUCS

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KASAN: slab-use-after-free Read in jfs_strfromUCS_le jfs	19				1	495d	490d	0/29	auto-obsoleted due to no activity on 2024/08/04 22:43
upstream	KASAN: slab-out-of-bounds Read in jfs_strfromUCS_le jfs	17				1	243d	237d	0/29	auto-obsoleted due to no activity on 2025/04/13 22:04
ERROR: (device loop3): jfs_readdir: JFS:Dtree error: ino = 2, bn=0, index = 3
non-latin1 character 0x3a73 found in JFS file name
mount with iocharset=utf8 to access
==================================================================
BUG: KASAN: slab-use-after-free in jfs_strfromUCS_le+0x234/0x330 fs/jfs/jfs_unicode.c:40
Read of size 2 at addr ffff0000de0ebeea by task syz-executor/6548

CPU: 1 UID: 0 PID: 6548 Comm: syz-executor Not tainted 6.17.0-rc1-syzkaller-g8f5ae30d69d7 #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 print_address_description+0xa8/0x238 mm/kasan/report.c:378
 print_report+0x68/0x84 mm/kasan/report.c:482
 kasan_report+0xb0/0x110 mm/kasan/report.c:595
 __asan_report_load2_noabort+0x20/0x2c mm/kasan/report_generic.c:379
 jfs_strfromUCS_le+0x234/0x330 fs/jfs/jfs_unicode.c:40
 jfs_readdir+0x1280/0x3018 fs/jfs/jfs_dtree.c:2987
 wrap_directory_iterator+0x90/0xf0 fs/readdir.c:65
 shared_jfs_readdir+0x30/0x40 fs/jfs/namei.c:1540
 iterate_dir+0x2dc/0x478 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:410 [inline]
 __se_sys_getdents64 fs/readdir.c:396 [inline]
 __arm64_sys_getdents64+0x110/0x2fc fs/readdir.c:396
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

Allocated by task 7318:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x40/0x78 mm/kasan/common.c:68
 kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:562
 unpoison_slab_object mm/kasan/common.c:330 [inline]
 __kasan_slab_alloc+0x70/0x88 mm/kasan/common.c:356
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4180 [inline]
 slab_alloc_node mm/slub.c:4229 [inline]
 kmem_cache_alloc_lru_noprof+0x23c/0x3ec mm/slub.c:4248
 jfs_alloc_inode+0x2c/0x68 fs/jfs/super.c:105
 alloc_inode+0x68/0x19c fs/inode.c:346
 iget_locked+0x168/0x7b0 fs/inode.c:1438
 jfs_iget+0x30/0x388 fs/jfs/inode.c:29
 jfs_lookup+0x198/0x32c fs/jfs/namei.c:1469
 __lookup_slow+0x254/0x378 fs/namei.c:1808
 lookup_slow+0x5c/0x80 fs/namei.c:1825
 walk_component fs/namei.c:2129 [inline]
 link_path_walk+0x790/0xc98 fs/namei.c:2497
 path_parentat fs/namei.c:2701 [inline]
 __filename_parentat+0x1c8/0x544 fs/namei.c:2725
 filename_parentat fs/namei.c:2743 [inline]
 filename_create+0xd0/0x32c fs/namei.c:4120
 do_mknodat+0x178/0x4a8 fs/namei.c:4272
 __do_sys_mknodat fs/namei.c:4313 [inline]
 __se_sys_mknodat fs/namei.c:4310 [inline]
 __arm64_sys_mknodat+0xac/0xc8 fs/namei.c:4310
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

Freed by task 7318:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x40/0x78 mm/kasan/common.c:68
 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:243 [inline]
 __kasan_slab_free+0x74/0x98 mm/kasan/common.c:275
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2417 [inline]
 slab_free mm/slub.c:4680 [inline]
 kmem_cache_free+0x184/0x550 mm/slub.c:4782
 jfs_free_inode+0x28/0x38 fs/jfs/super.c:116
 i_callback+0x50/0x78 fs/inode.c:325
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0x840/0x17d0 kernel/rcu/tree.c:2861
 rcu_core_si+0x10/0x1c kernel/rcu/tree.c:2878
 handle_softirqs+0x328/0xc88 kernel/softirq.c:579
 __do_softirq+0x14/0x20 kernel/softirq.c:613

Last potentially related work creation:
 kasan_save_stack+0x40/0x6c mm/kasan/common.c:47
 kasan_record_aux_stack+0xb0/0xc8 mm/kasan/generic.c:548
 __call_rcu_common kernel/rcu/tree.c:3123 [inline]
 call_rcu+0x100/0x978 kernel/rcu/tree.c:3243
 destroy_inode fs/inode.c:401 [inline]
 evict+0x754/0x928 fs/inode.c:834
 iput_final fs/inode.c:1897 [inline]
 iput+0x6e4/0x83c fs/inode.c:1923
 iget_failed+0xec/0x134 fs/bad_inode.c:248
 jfs_iget+0x150/0x388 fs/jfs/inode.c:37
 jfs_lookup+0x198/0x32c fs/jfs/namei.c:1469
 __lookup_slow+0x254/0x378 fs/namei.c:1808
 lookup_slow+0x5c/0x80 fs/namei.c:1825
 walk_component fs/namei.c:2129 [inline]
 link_path_walk+0x790/0xc98 fs/namei.c:2497
 path_parentat fs/namei.c:2701 [inline]
 __filename_parentat+0x1c8/0x544 fs/namei.c:2725
 filename_parentat fs/namei.c:2743 [inline]
 filename_create+0xd0/0x32c fs/namei.c:4120
 do_mknodat+0x178/0x4a8 fs/namei.c:4272
 __do_sys_mknodat fs/namei.c:4313 [inline]
 __se_sys_mknodat fs/namei.c:4310 [inline]
 __arm64_sys_mknodat+0xac/0xc8 fs/namei.c:4310
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

The buggy address belongs to the object at ffff0000de0eb750
 which belongs to the cache jfs_ip of size 2232
The buggy address is located 1946 bytes inside of
 freed 2232-byte region [ffff0000de0eb750, ffff0000de0ec008)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11e0e8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff0000fdaf2401
flags: 0x5ffc00000000040(head|node=0|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 05ffc00000000040 ffff0000c48dca00 dead000000000122 0000000000000000
raw: 0000000000000000 00000000800d000d 00000000f5000000 ffff0000fdaf2401
head: 05ffc00000000040 ffff0000c48dca00 dead000000000122 0000000000000000
head: 0000000000000000 00000000800d000d 00000000f5000000 ffff0000fdaf2401
head: 05ffc00000000003 fffffdffc3783a01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000de0ebd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000de0ebe00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000de0ebe80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff0000de0ebf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000de0ebf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
non-latin1 character 0xffff found in JFS file name
mount with iocharset=utf8 to access
ERROR: (device loop3): jfs_readdir: JFS:Dtree error: ino = 2, bn=0, index = 5

ERROR: (device loop3): jfs_readdir: JFS:Dtree error: ino = 2, bn=0, index = 6

ERROR: (device loop3): jfs_readdir: JFS:Dtree error: ino = 2, bn=0, index = 7

jfs_lookup: iget failed on inum 32
jfs_lookup: iget failed on inum 32
jfs_lookup: iget failed on inum 32
jfs_lookup: iget failed on inum 32