Message-ID: <000000000000022a3f06061d7e02@google.com>
Date:   Sun, 24 Sep 2023 09:39:58 -0700
From:   syzbot <syzbot+2751da923b5eb8307b0b@...kaller.appspotmail.com>
To:     anton@...era.com, linkinjeon@...nel.org,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-ntfs-dev@...ts.sourceforge.net, phil@...lpotter.co.uk,
        syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [ntfs?] KASAN: use-after-free Read in ntfs_test_inode

syzbot has found a reproducer for the following issue on:

HEAD commit:    3aba70aed91f Merge tag 'gpio-fixes-for-v6.6-rc3' of git://..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=10fa1c8e680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e4ca82a1bedd37e4
dashboard link: https://syzkaller.appspot.com/bug?extid=2751da923b5eb8307b0b
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=136b4412680000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11aec0dc680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5fa097a40129/disk-3aba70ae.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/13b28020a934/vmlinux-3aba70ae.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7f3b0a1bf798/bzImage-3aba70ae.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/215dc95e52e5/mount_0.gz
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/b88b05ac266b/mount_1.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2751da923b5eb8307b0b@...kaller.appspotmail.com

loop0: detected capacity change from 0 to 4096
==================================================================
BUG: KASAN: slab-out-of-bounds in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: slab-out-of-bounds in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: slab-out-of-bounds in NInoAttr fs/ntfs/inode.h:200 [inline]
BUG: KASAN: slab-out-of-bounds in ntfs_test_inode+0x7f/0x2e0 fs/ntfs/inode.c:55
Read of size 8 at addr ffff888077b1df60 by task syz-executor108/5863

CPU: 0 PID: 5863 Comm: syz-executor108 Not tainted 6.6.0-rc2-syzkaller-00386-g3aba70aed91f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x163/0x540 mm/kasan/report.c:475
 kasan_report+0x175/0x1b0 mm/kasan/report.c:588
 kasan_check_range+0x27e/0x290 mm/kasan/generic.c:187
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 NInoAttr fs/ntfs/inode.h:200 [inline]
 ntfs_test_inode+0x7f/0x2e0 fs/ntfs/inode.c:55
 find_inode+0x16f/0x430 fs/inode.c:901
 ilookup5_nowait fs/inode.c:1456 [inline]
 ilookup5+0xa1/0x200 fs/inode.c:1485
 iget5_locked+0x37/0x270 fs/inode.c:1266
 ntfs_attr_iget+0x1b5/0x2420 fs/ntfs/inode.c:229
 load_system_files+0x1333/0x4840 fs/ntfs/super.c:1808
 ntfs_fill_super+0x19b3/0x2bd0 fs/ntfs/super.c:2900
 mount_bdev+0x237/0x300 fs/super.c:1629
 legacy_get_tree+0xef/0x190 fs/fs_context.c:638
 vfs_get_tree+0x8c/0x280 fs/super.c:1750
 do_new_mount+0x28f/0xae0 fs/namespace.c:3335
 do_mount fs/namespace.c:3675 [inline]
 __do_sys_mount fs/namespace.c:3884 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f79473960aa
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f7947351028 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f79473960aa
RDX: 000000002001f6c0 RSI: 000000002001f640 RDI: 00007f7947351080
RBP: 000000002001f6c0 R08: 00007f79473510c0 R09: 000000000001f63f
R10: 0000000000008703 R11: 0000000000000286 R12: 00007f7947351080
R13: 000000002001f640 R14: 000000000001f646 R15: 00007f79473510c0
 </TASK>

Allocated by task 5059:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4f/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x66/0x70 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x67/0x3d0 mm/slab.h:762
 slab_alloc_node mm/slub.c:3478 [inline]
 slab_alloc mm/slub.c:3486 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3493 [inline]
 kmem_cache_alloc_lru+0x122/0x300 mm/slub.c:3509
 alloc_inode_sb include/linux/fs.h:2868 [inline]
 ntfs_alloc_inode+0x28/0x80 fs/ntfs3/super.c:546
 alloc_inode fs/inode.c:259 [inline]
 iget5_locked+0xa0/0x270 fs/inode.c:1269
 ntfs_iget5+0xc6/0x38e0 fs/ntfs3/inode.c:525
 ntfs_fill_super+0x2dec/0x4c30 fs/ntfs3/super.c:1244
 get_tree_bdev+0x416/0x5b0 fs/super.c:1577
 vfs_get_tree+0x8c/0x280 fs/super.c:1750
 do_new_mount+0x28f/0xae0 fs/namespace.c:3335
 do_mount fs/namespace.c:3675 [inline]
 __do_sys_mount fs/namespace.c:3884 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff888077b1d880
 which belongs to the cache ntfs_inode_cache of size 1760
The buggy address is located 0 bytes to the right of
 allocated 1760-byte region [ffff888077b1d880, ffff888077b1df60)

The buggy address belongs to the physical page:
page:ffffea0001dec600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77b18
head:ffffea0001dec600 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888141666c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000110011 00000001ffffffff 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 0xd2050(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_RECLAIMABLE), pid 5056, tgid 5054 (syz-executor108), ts 62202039156, free_ts 18025050030
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1536
 prep_new_page mm/page_alloc.c:1543 [inline]
 get_page_from_freelist+0x31db/0x3360 mm/page_alloc.c:3170
 __alloc_pages+0x255/0x670 mm/page_alloc.c:4426
 alloc_slab_page+0x6a/0x160 mm/slub.c:1870
 allocate_slab mm/slub.c:2017 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2070
 ___slab_alloc+0xc85/0x1310 mm/slub.c:3223
 __slab_alloc mm/slub.c:3322 [inline]
 __slab_alloc_node mm/slub.c:3375 [inline]
 slab_alloc_node mm/slub.c:3468 [inline]
 slab_alloc mm/slub.c:3486 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3493 [inline]
 kmem_cache_alloc_lru+0x1bf/0x300 mm/slub.c:3509
 alloc_inode_sb include/linux/fs.h:2868 [inline]
 ntfs_alloc_inode+0x28/0x80 fs/ntfs3/super.c:546
 alloc_inode fs/inode.c:259 [inline]
 iget5_locked+0xa0/0x270 fs/inode.c:1269
 ntfs_iget5+0xc6/0x38e0 fs/ntfs3/inode.c:525
 ntfs_fill_super+0x2459/0x4c30 fs/ntfs3/super.c:1150
 get_tree_bdev+0x416/0x5b0 fs/super.c:1577
 vfs_get_tree+0x8c/0x280 fs/super.c:1750
 do_new_mount+0x28f/0xae0 fs/namespace.c:3335
 do_mount fs/namespace.c:3675 [inline]
 __do_sys_mount fs/namespace.c:3884 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1136 [inline]
 free_unref_page_prepare+0x8c3/0x9f0 mm/page_alloc.c:2312
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2405
 free_contig_range+0x9e/0x150 mm/page_alloc.c:6342
 destroy_args+0x95/0x7c0 mm/debug_vm_pgtable.c:1028
 debug_vm_pgtable+0x4ba/0x540 mm/debug_vm_pgtable.c:1408
 do_one_initcall+0x23d/0x7d0 init/main.c:1232
 do_initcall_level+0x157/0x210 init/main.c:1294
 do_initcalls+0x3f/0x80 init/main.c:1310
 kernel_init_freeable+0x429/0x5c0 init/main.c:1547
 kernel_init+0x1d/0x2a0 init/main.c:1437
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Memory state around the buggy address:
 ffff888077b1de00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888077b1de80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888077b1df00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
                                                       ^
 ffff888077b1df80: fc fc fc fc fc fc fc fc fc fc fc fc 00 00 00 00
 ffff888077b1e000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

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