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

[syzbot <syzbot+5d34cc6474499a5ff516@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in chrdev_open

loop0: detected capacity change from 0 to 4096
==================================================================
BUG: KASAN: slab-use-after-free in __list_add_valid_or_report+0x4c/0xf0 lib/list_debug.c:29
Read of size 8 at addr ffff8880433aba48 by task syz-executor.0/5464

CPU: 1 PID: 5464 Comm: syz-executor.0 Not tainted 6.10.0-rc3-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
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
 __list_add_valid_or_report+0x4c/0xf0 lib/list_debug.c:29
 __list_add_valid include/linux/list.h:88 [inline]
 __list_add include/linux/list.h:150 [inline]
 list_add include/linux/list.h:169 [inline]
 chrdev_open+0x2a9/0x630 fs/char_dev.c:396
 do_dentry_open+0x98f/0x1750 fs/open.c:958
 do_open fs/namei.c:3650 [inline]
 path_openat+0x289f/0x3280 fs/namei.c:3807
 do_filp_open+0x235/0x490 fs/namei.c:3834
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1408
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1434
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6f9567dea9
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:00007f6f963b60c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f6f957abf80 RCX: 00007f6f9567dea9
RDX: 0000000000000000 RSI: 0000000020002140 RDI: ffffffffffffff9c
RBP: 00007f6f956ca4a4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f6f957abf80 R15: 00007fffeeba0e38
 </TASK>

Allocated by task 5451:
 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:3941 [inline]
 slab_alloc_node mm/slub.c:4001 [inline]
 kmem_cache_alloc_lru_noprof+0x139/0x2b0 mm/slub.c:4020
 ntfs_alloc_inode+0x28/0x80 fs/ntfs3/super.c:563
 alloc_inode fs/inode.c:261 [inline]
 new_inode_pseudo+0x69/0x1e0 fs/inode.c:1007
 new_inode+0x22/0x1d0 fs/inode.c:1033
 ntfs_new_inode+0x45/0x100 fs/ntfs3/fsntfs.c:1688
 ntfs_create_inode+0x5f1/0x3680 fs/ntfs3/inode.c:1347
 ntfs_mknod+0x3c/0x50 fs/ntfs3/namei.c:122
 vfs_mknod+0x36d/0x3b0 fs/namei.c:4009
 do_mknodat+0x3ec/0x5b0
 __do_sys_mknodat fs/namei.c:4087 [inline]
 __se_sys_mknodat fs/namei.c:4084 [inline]
 __x64_sys_mknodat+0xa9/0xc0 fs/namei.c:4084
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 16:
 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+0xe0/0x150 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:2196 [inline]
 slab_free mm/slub.c:4437 [inline]
 kmem_cache_free+0x145/0x350 mm/slub.c:4512
 rcu_do_batch kernel/rcu/tree.c:2535 [inline]
 rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2809
 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
 run_ksoftirqd+0xca/0x130 kernel/softirq.c:928
 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

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:3072 [inline]
 call_rcu+0x167/0xa70 kernel/rcu/tree.c:3176
 __dentry_kill+0x20d/0x630 fs/dcache.c:603
 shrink_kill+0xa9/0x2c0 fs/dcache.c:1048
 shrink_dentry_list+0x2c0/0x5b0 fs/dcache.c:1075
 shrink_dcache_parent+0xcb/0x3b0
 do_one_tree+0x23/0xe0 fs/dcache.c:1538
 shrink_dcache_for_umount+0x7d/0x130 fs/dcache.c:1555
 generic_shutdown_super+0x6a/0x2d0 fs/super.c:620
 kill_block_super+0x44/0x90 fs/super.c:1676
 ntfs3_kill_sb+0x44/0x1b0 fs/ntfs3/super.c:1798
 deactivate_locked_super+0xc4/0x130 fs/super.c:473
 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1275
 task_work_run+0x24f/0x310 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880433ab3a0
 which belongs to the cache ntfs_inode_cache of size 1760
The buggy address is located 1704 bytes inside of
 freed 1760-byte region [ffff8880433ab3a0, ffff8880433aba80)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x433a8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88802367d401
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffefff(slab)
raw: 00fff00000000040 ffff88801a37bc80 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080110011 00000001ffffefff ffff88802367d401
head: 00fff00000000040 ffff88801a37bc80 dead000000000122 0000000000000000
head: 0000000000000000 0000000080110011 00000001ffffefff ffff88802367d401
head: 00fff00000000003 ffffea00010cea01 ffffffffffffffff 0000000000000000
head: 0000000000000008 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 5451, tgid 5450 (syz-executor.0), ts 85231803751, free_ts 15194610819
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1468
 prep_new_page mm/page_alloc.c:1476 [inline]
 get_page_from_freelist+0x2e43/0x2f00 mm/page_alloc.c:3420
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4678
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x5f/0x120 mm/slub.c:2265
 allocate_slab+0x5a/0x2f0 mm/slub.c:2428
 new_slab mm/slub.c:2481 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3667
 __slab_alloc+0x58/0xa0 mm/slub.c:3757
 __slab_alloc_node mm/slub.c:3810 [inline]
 slab_alloc_node mm/slub.c:3989 [inline]
 kmem_cache_alloc_lru_noprof+0x1c5/0x2b0 mm/slub.c:4020
 ntfs_alloc_inode+0x28/0x80 fs/ntfs3/super.c:563
 alloc_inode fs/inode.c:261 [inline]
 iget5_locked+0xa4/0x280 fs/inode.c:1235
 ntfs_iget5+0xd5/0x3b10 fs/ntfs3/inode.c:532
 ntfs_security_init+0x110/0xcc0 fs/ntfs3/fsntfs.c:1882
 ntfs_fill_super+0x4329/0x4a20 fs/ntfs3/super.c:1530
 get_tree_bdev+0x3f7/0x570 fs/super.c:1615
 vfs_get_tree+0x90/0x2a0 fs/super.c:1780
 do_new_mount+0x2be/0xb40 fs/namespace.c:3360
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1088 [inline]
 free_unref_page+0xd19/0xea0 mm/page_alloc.c:2583
 free_contig_range+0x9e/0x160 mm/page_alloc.c:6637
 destroy_args+0x8a/0x890 mm/debug_vm_pgtable.c:1038
 debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1418
 do_one_initcall+0x248/0x880 init/main.c:1267
 do_initcall_level+0x157/0x210 init/main.c:1329
 do_initcalls+0x3f/0x80 init/main.c:1345
 kernel_init_freeable+0x435/0x5d0 init/main.c:1578
 kernel_init+0x1d/0x2b0 init/main.c:1467
 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:
 ffff8880433ab900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880433ab980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880433aba00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff8880433aba80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880433abb00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         83a7eefe Linux 6.10-rc3
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=14c92012980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c79815c08cc14227
dashboard link: https://syzkaller.appspot.com/bug?extid=5d34cc6474499a5ff516
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=17df5446980000