[syzbot] [ntfs3?] KASAN: slab-use-after-free Read in attr_set_size_ex

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0131b508c0e2 Merge tag 'ntfs-for-7.2-rc6' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=141394c6580000
kernel config: https://syzkaller.appspot.com/x/.config?x=cb17729fb04b1e3a
dashboard link: https://syzkaller.appspot.com/bug?extid=2e386579af3ad9319a5b
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0c726c97610c/disk-0131b508.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/054495aca287/vmlinux-0131b508.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a11b49533ef4/bzImage-0131b508.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2e3865...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in attr_set_size_ex+0x2e14/0x2e70 fs/ntfs3/attrib.c:451
Read of size 2 at addr ffff88802a872bdc by task syz.1.298/8028

CPU: 1 UID: 0 PID: 8028 Comm: syz.1.298 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description+0x55/0x1e0 mm/kasan/report.c:378
print_report+0x58/0x70 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
attr_set_size_ex+0x2e14/0x2e70 fs/ntfs3/attrib.c:451
attr_set_size fs/ntfs3/ntfs_fs.h:466 [inline]
ntfs_set_size+0x1e1/0x270 fs/ntfs3/inode.c:701
ntfs_file_write_iter+0x4e3/0xab0 fs/ntfs3/file.c:1268
iter_file_splice_write+0xa36/0x1240 fs/splice.c:736
do_splice_from fs/splice.c:936 [inline]
direct_splice_actor+0x104/0x160 fs/splice.c:1159
splice_direct_to_actor+0x586/0xcc0 fs/splice.c:1103
do_splice_direct_actor fs/splice.c:1202 [inline]
do_splice_direct+0x19b/0x2a0 fs/splice.c:1228
do_sendfile+0x540/0x7e0 fs/read_write.c:1371
__do_sys_sendfile64 fs/read_write.c:1432 [inline]
__se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1418
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd797f5e019
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd7961b6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fd7981e5fa0 RCX: 00007fd797f5e019
RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000006
RBP: 00007fd797ff500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020fffe82 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd7981e6038 R14: 00007fd7981e5fa0 R15: 00007ffeb63a81a8
</TASK>

Allocated by task 8028:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5334 [inline]
__kmalloc_node_track_caller_noprof+0x57f/0x7c0 mm/slub.c:5471
kmemdup_noprof+0x2b/0x70 mm/util.c:138
kmemdup_noprof include/linux/fortify-string.h:715 [inline]
ntfs_fill_super+0x1e2/0x45d0 fs/ntfs3/super.c:1273
get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1640
vfs_get_tree+0x92/0x2a0 fs/super.c:1700
fc_mount fs/namespace.c:1198 [inline]
do_new_mount_fc fs/namespace.c:3765 [inline]
do_new_mount+0x319/0xdc0 fs/namespace.c:3841
do_mount fs/namespace.c:4174 [inline]
__do_sys_mount fs/namespace.c:4390 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4367
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 8040:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2677 [inline]
slab_free mm/slub.c:6377 [inline]
kfree+0x1c5/0x6c0 mm/slub.c:6692
put_fs_context+0x123/0xb00 fs/fs_context.c:498
do_remount fs/namespace.c:3419 [inline]
path_mount+0xef9/0x1040 fs/namespace.c:4153
do_mount fs/namespace.c:4174 [inline]
__do_sys_mount fs/namespace.c:4390 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4367
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802a872bc0
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 28 bytes inside of
freed 32-byte region [ffff88802a872bc0, ffff88802a872be0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2a872
flags: 0x80000000000000(node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000000 ffff88813ffb2780 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800400040 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4949, tgid 4949 (S01syslogd), ts 31763015621, free_ts 31761933864
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859
prep_new_page mm/page_alloc.c:1867 [inline]
get_page_from_freelist+0x262a/0x26a0 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304
alloc_slab_page mm/slub.c:3266 [inline]
allocate_slab+0x79/0x5e0 mm/slub.c:3380
new_slab mm/slub.c:3426 [inline]
refill_objects+0x2d8/0x350 mm/slub.c:7310
refill_sheaf mm/slub.c:2804 [inline]
__pcs_replace_empty_main+0x330/0x690 mm/slub.c:4675
alloc_from_pcs mm/slub.c:4773 [inline]
slab_alloc_node mm/slub.c:4905 [inline]
__kmalloc_cache_noprof+0x468/0x6b0 mm/slub.c:5485
_kmalloc_noprof include/linux/slab.h:988 [inline]
slab_free_hook mm/slub.c:2629 [inline]
slab_free mm/slub.c:6377 [inline]
kmem_cache_free+0x156/0x6c0 mm/slub.c:6504
tear_down_vmas+0x312/0x520 mm/mmap.c:1262
exit_mmap+0x4ca/0x9f0 mm/mmap.c:1320
__mmput+0xcb/0x3d0 kernel/fork.c:1187
exec_mm_put_old fs/exec.c:916 [inline]
setup_new_exec+0x30d/0x360 fs/exec.c:1353
load_elf_binary+0xbd6/0x2970 fs/binfmt_elf.c:1024
search_binary_handler fs/exec.c:1694 [inline]
exec_binprm fs/exec.c:1726 [inline]
bprm_execve+0x926/0x14b0 fs/exec.c:1778
do_execveat_common+0x4f4/0x670 fs/exec.c:1876
__do_sys_execve fs/exec.c:1949 [inline]
__se_sys_execve fs/exec.c:1943 [inline]
__x64_sys_execve+0x97/0xc0 fs/exec.c:1943
page last free pid 4949 tgid 4949 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0x10e7/0x11c0 mm/page_alloc.c:2950
tlb_batch_list_free mm/mmu_gather.c:161 [inline]
tlb_finish_mmu+0x13e/0x220 mm/mmu_gather.c:552
exit_mmap+0x4b2/0x9f0 mm/mmap.c:1313
__mmput+0xcb/0x3d0 kernel/fork.c:1187
exec_mm_put_old fs/exec.c:916 [inline]
setup_new_exec+0x30d/0x360 fs/exec.c:1353
load_elf_binary+0xbd6/0x2970 fs/binfmt_elf.c:1024
search_binary_handler fs/exec.c:1694 [inline]
exec_binprm fs/exec.c:1726 [inline]
bprm_execve+0x926/0x14b0 fs/exec.c:1778
do_execveat_common+0x4f4/0x670 fs/exec.c:1876
__do_sys_execve fs/exec.c:1949 [inline]
__se_sys_execve fs/exec.c:1943 [inline]
__x64_sys_execve+0x97/0xc0 fs/exec.c:1943
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
ffff88802a872a80: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc
ffff88802a872b00: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc
>ffff88802a872b80: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc
^
ffff88802a872c00: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
ffff88802a872c80: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
==================================================================


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