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

Status: upstream: reported on 2024/05/02 08:39
Subsystems: jfs
[Documentation on labels]
Reported-by: syzbot+c7019fac44a50a2ab16f@syzkaller.appspotmail.com
First crash: 52d, last: 52d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [jfs?] KASAN: slab-use-after-free Read in jfs_strfromUCS_le 0 (1) 2024/05/02 08:39

Sample crash report:
ERROR: (device loop3): remounting filesystem as read-only
non-latin1 character 0x706d found in JFS file name
mount with iocharset=utf8 to access
==================================================================
BUG: KASAN: slab-use-after-free in jfs_strfromUCS_le+0x28d/0x3b0 fs/jfs/jfs_unicode.c:40
Read of size 2 at addr ffff8880641f2d32 by task syz-executor.3/6266

CPU: 1 PID: 6266 Comm: syz-executor.3 Not tainted 6.9.0-rc5-syzkaller-00159-gc942a0cd3603 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 jfs_strfromUCS_le+0x28d/0x3b0 fs/jfs/jfs_unicode.c:40
 jfs_readdir+0x19b6/0x4660 fs/jfs/jfs_dtree.c:2965
 wrap_directory_iterator+0x94/0xe0 fs/readdir.c:67
 iterate_dir+0x539/0x6f0 fs/readdir.c:110
 __do_sys_getdents64 fs/readdir.c:409 [inline]
 __se_sys_getdents64+0x20d/0x4f0 fs/readdir.c:394
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f35f267dea9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f35f33a90c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007f35f27abf80 RCX: 00007f35f267dea9
RDX: 0000000000001000 RSI: 0000000020000f80 RDI: 0000000000000009
RBP: 00007f35f26ca4a4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f35f27abf80 R15: 00007fff3bf15438
 </TASK>

Allocated by task 6266:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3798 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 kmem_cache_alloc_lru+0x178/0x350 mm/slub.c:3864
 alloc_inode_sb include/linux/fs.h:3091 [inline]
 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105
 alloc_inode fs/inode.c:261 [inline]
 iget_locked+0x1ad/0x850 fs/inode.c:1280
 jfs_iget+0x22/0x3b0 fs/jfs/inode.c:29
 jfs_lookup+0x226/0x410 fs/jfs/namei.c:1469
 __lookup_slow+0x28c/0x3f0 fs/namei.c:1692
 lookup_slow+0x53/0x70 fs/namei.c:1709
 walk_component+0x2e1/0x410 fs/namei.c:2004
 lookup_last fs/namei.c:2461 [inline]
 path_lookupat+0x16f/0x450 fs/namei.c:2485
 filename_lookup+0x256/0x610 fs/namei.c:2514
 user_path_at_empty+0x42/0x60 fs/namei.c:2921
 user_path_at include/linux/namei.h:57 [inline]
 do_mount fs/namespace.c:3689 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x29a/0x3c0 fs/namespace.c:3875
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1563:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2106 [inline]
 slab_free mm/slub.c:4280 [inline]
 kmem_cache_free+0x10b/0x2c0 mm/slub.c:4344
 rcu_do_batch kernel/rcu/tree.c:2196 [inline]
 rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2471
 __do_softirq+0x2c6/0x980 kernel/softirq.c:554

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
 __call_rcu_common kernel/rcu/tree.c:2734 [inline]
 call_rcu+0x167/0xa70 kernel/rcu/tree.c:2838
 jfs_iget+0x18d/0x3b0 fs/jfs/inode.c:37
 jfs_lookup+0x226/0x410 fs/jfs/namei.c:1469
 __lookup_slow+0x28c/0x3f0 fs/namei.c:1692
 lookup_slow+0x53/0x70 fs/namei.c:1709
 walk_component+0x2e1/0x410 fs/namei.c:2004
 lookup_last fs/namei.c:2461 [inline]
 path_lookupat+0x16f/0x450 fs/namei.c:2485
 filename_lookup+0x256/0x610 fs/namei.c:2514
 user_path_at_empty+0x42/0x60 fs/namei.c:2921
 user_path_at include/linux/namei.h:57 [inline]
 do_mount fs/namespace.c:3689 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x29a/0x3c0 fs/namespace.c:3875
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880641f2500
 which belongs to the cache jfs_ip of size 2240
The buggy address is located 2098 bytes inside of
 freed 2240-byte region [ffff8880641f2500, ffff8880641f2dc0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880641f0940 pfn:0x641f0
head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888028d26e01
flags: 0xfff80000000840(slab|head|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000840 ffff8880197d13c0 dead000000000122 0000000000000000
raw: ffff8880641f0940 00000000800d000b 00000001ffffffff ffff888028d26e01
head: 00fff80000000840 ffff8880197d13c0 dead000000000122 0000000000000000
head: ffff8880641f0940 00000000800d000b 00000001ffffffff ffff888028d26e01
head: 00fff80000000003 ffffea0001907c01 dead000000000122 00000000ffffffff
head: 0000000800000000 0000000000000000 00000000ffffffff 0000000000000000
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 5433, tgid -1337237977 (syz-executor.3), ts 5435, free_ts 62450070106
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0x3410/0x35b0 mm/page_alloc.c:3317
 __alloc_pages+0x256/0x6c0 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page+0x5f/0x160 mm/slub.c:2175
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2391
 ___slab_alloc+0xc73/0x1260 mm/slub.c:3525
 __slab_alloc mm/slub.c:3610 [inline]
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 kmem_cache_alloc_lru+0x253/0x350 mm/slub.c:3864
 alloc_inode_sb include/linux/fs.h:3091 [inline]
 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105
 alloc_inode fs/inode.c:261 [inline]
 iget_locked+0x1ad/0x850 fs/inode.c:1280
 jfs_iget+0x22/0x3b0 fs/jfs/inode.c:29
 jfs_lookup+0x226/0x410 fs/jfs/namei.c:1469
 lookup_one_qstr_excl+0x11f/0x260 fs/namei.c:1607
 do_unlinkat+0x297/0x830 fs/namei.c:4387
 __do_sys_unlink fs/namei.c:4447 [inline]
 __se_sys_unlink fs/namei.c:4445 [inline]
 __x64_sys_unlink+0x49/0x60 fs/namei.c:4445
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 50 tgid 50 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x97b/0xaa0 mm/page_alloc.c:2347
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487
 __folio_put_large+0x13f/0x190 mm/swap.c:132
 __folio_put+0x299/0x390 mm/swap.c:140
 io_rings_free+0x76/0x370 io_uring/io_uring.c:2801
 io_ring_ctx_free+0x798/0x9a0 io_uring/io_uring.c:2923
 io_ring_exit_work+0x7c7/0x850 io_uring/io_uring.c:3136
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff8880641f2c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880641f2c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880641f2d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8880641f2d80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8880641f2e00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/26 22:42 upstream c942a0cd3603 059e9963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in jfs_strfromUCS_le
* Struck through repros no longer work on HEAD.