From: Christoph Hellwig <hch@infradead.org>
To: Qu Wenruo <quwenruo.btrfs@gmx.com>
Cc: Christoph Hellwig <hch@infradead.org>, linux-btrfs@vger.kernel.org
Subject: Re: btrfs/071 is unhappy on 6.18-rc2
Date: Mon, 20 Oct 2025 07:19:39 -0700 [thread overview]
Message-ID: <aPZE--T-nj0dKB0A@infradead.org> (raw)
In-Reply-To: <cc22f604-25f2-407c-bbb8-887e18630819@gmx.com>
KASAN output:
[ 75.341543] ==================================================================
[ 75.341824] BUG: KASAN: slab-use-after-free in btrfs_kill_all_delayed_nodes+0x46f/0x4c0
[ 75.342082] Read of size 8 at addr ffff88812389f380 by task btrfs-cleaner/4493
[ 75.342310]
[ 75.342369] CPU: 1 UID: 0 PID: 4493 Comm: btrfs-cleaner Tainted: G N 6.18.0-rc2+ #4115 PREEMPT(f
[ 75.342372] Tainted: [N]=TEST
[ 75.342373] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 75.342374] Call Trace:
[ 75.342375] <TASK>
[ 75.342376] dump_stack_lvl+0x4b/0x70
[ 75.342379] print_report+0x174/0x4e7
[ 75.342382] ? __virt_addr_valid+0x1bb/0x2f0
[ 75.342384] ? btrfs_kill_all_delayed_nodes+0x46f/0x4c0
[ 75.342385] kasan_report+0xd2/0x100
[ 75.342387] ? btrfs_kill_all_delayed_nodes+0x46f/0x4c0
[ 75.342388] btrfs_kill_all_delayed_nodes+0x46f/0x4c0
[ 75.342389] ? _raw_spin_unlock+0x13/0x30
[ 75.342392] ? __pfx_btrfs_kill_all_delayed_nodes+0x10/0x10
[ 75.342393] ? do_raw_spin_lock+0x128/0x260
[ 75.342395] ? __pfx_do_raw_spin_lock+0x10/0x10
[ 75.342397] ? list_lru_add_obj+0xfb/0x1a0
[ 75.342399] ? do_raw_spin_lock+0x128/0x260
[ 75.342401] ? __pfx_do_raw_spin_lock+0x10/0x10
[ 75.342402] btrfs_clean_one_deleted_snapshot+0x143/0x370
[ 75.342405] cleaner_kthread+0x1ee/0x300
[ 75.342406] ? __pfx_cleaner_kthread+0x10/0x10
[ 75.342407] kthread+0x37f/0x6f0
[ 75.342409] ? __pfx_kthread+0x10/0x10
[ 75.342411] ? __pfx_kthread+0x10/0x10
[ 75.342412] ? __pfx_kthread+0x10/0x10
[ 75.342413] ret_from_fork+0x17d/0x240
[ 75.342415] ? __pfx_kthread+0x10/0x10
[ 75.342416] ret_from_fork_asm+0x1a/0x30
[ 75.342419] </TASK>
[ 75.342419]
[ 75.345517] Allocated by task 4527:
[ 75.345517] kasan_save_stack+0x22/0x40
[ 75.345517] kasan_save_track+0x14/0x30
[ 75.345517] __kasan_slab_alloc+0x6e/0x70
[ 75.345517] kmem_cache_alloc_noprof+0x14c/0x400
[ 75.345517] btrfs_get_or_create_delayed_node+0x9e/0x9e0
[ 75.345517] btrfs_insert_delayed_dir_index+0xe4/0x8a0
[ 75.345517] btrfs_insert_dir_item+0x4c1/0x720
[ 75.345517] btrfs_add_link+0x173/0xa30
[ 75.345517] btrfs_create_new_inode+0x1551/0x2650
[ 75.345517] btrfs_create_common+0x17b/0x200
[ 75.345517] vfs_mknod+0x3a7/0x600
[ 75.345517] do_mknodat+0x34e/0x520
[ 75.345517] __x64_sys_mknodat+0xaa/0xe0
[ 75.345517] do_syscall_64+0x50/0xfa0
[ 75.345517] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 75.345517]
[ 75.345517] Freed by task 4493:
[ 75.345517] kasan_save_stack+0x22/0x40
[ 75.345517] kasan_save_track+0x14/0x30
[ 75.345517] __kasan_save_free_info+0x3b/0x70
[ 75.345517] __kasan_slab_free+0x43/0x70
[ 75.345517] kmem_cache_free+0x172/0x610
[ 75.345517] btrfs_kill_all_delayed_nodes+0x2db/0x4c0
[ 75.345517] btrfs_clean_one_deleted_snapshot+0x143/0x370
[ 75.345517] cleaner_kthread+0x1ee/0x300
[ 75.345517] kthread+0x37f/0x6f0
[ 75.345517] ret_from_fork+0x17d/0x240
[ 75.345517] ret_from_fork_asm+0x1a/0x30
[ 75.345517]
[ 75.345517] The buggy address belongs to the object at ffff88812389f370
[ 75.345517] which belongs to the cache btrfs_delayed_node of size 440
[ 75.345517] The buggy address is located 16 bytes inside of
[ 75.345517] freed 440-byte region [ffff88812389f370, ffff88812389f528)
[ 75.345517]
[ 75.345517] The buggy address belongs to the physical page:
[ 75.345517] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12389e
[ 75.345517] head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[ 75.345517] flags: 0x4000000000000040(head|zone=2)
[ 75.345517] page_type: f5(slab)
[ 75.345517] raw: 4000000000000040 ffff88810bcaadc0 ffffea0004487a10 ffff88810c6e6d80
[ 75.345517] raw: 0000000000000000 00000000000e000e 00000000f5000000 0000000000000000
[ 75.345517] head: 4000000000000040 ffff88810bcaadc0 ffffea0004487a10 ffff88810c6e6d80
[ 75.345517] head: 0000000000000000 00000000000e000e 00000000f5000000 0000000000000000
[ 75.345517] head: 4000000000000001 ffffea00048e2781 00000000ffffffff 00000000ffffffff
[ 75.345517] head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
[ 75.345517] page dumped because: kasan: bad access detected
[ 75.345517]
[ 75.345517] Memory state around the buggy address:
[ 75.345517] ffff88812389f280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 75.345517] ffff88812389f300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fa fb
[ 75.345517] >ffff88812389f380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 75.345517] ^
[ 75.345517] ffff88812389f400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 75.345517] ffff88812389f480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 75.345517] ==================================================================
[ 75.501545] Disabling lock debugging due to kernel taint
gdb) l *(btrfs_kill_all_delayed_nodes+0x46f)
0xffffffff82f2422f is in btrfs_kill_all_delayed_nodes (fs/btrfs/delayed-inode.h:219).
214 ref_tracker_dir_exit(&node->ref_dir.dir);
215 }
216
217 static inline void btrfs_delayed_node_ref_tracker_dir_print(struct btrfs_delayed_node *node)
218 {
219 if (!btrfs_test_opt(node->root->fs_info, REF_TRACKER))
220 return;
221
222 ref_tracker_dir_print(&node->ref_dir.dir,
223 BTRFS_DELAYED_NODE_REF_TRACKER_DISPLAY_LIMIT);
next prev parent reply other threads:[~2025-10-20 14:19 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-20 7:22 btrfs/071 is unhappy on 6.18-rc2 Christoph Hellwig
2025-10-20 9:11 ` Qu Wenruo
2025-10-20 9:46 ` Christoph Hellwig
2025-10-20 10:26 ` Qu Wenruo
2025-10-20 14:19 ` Christoph Hellwig [this message]
2025-10-20 16:55 ` Leo Martins
2025-10-20 23:25 ` Leo Martins
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=aPZE--T-nj0dKB0A@infradead.org \
--to=hch@infradead.org \
--cc=linux-btrfs@vger.kernel.org \
--cc=quwenruo.btrfs@gmx.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox