Message-ID: <67c7e22d.050a0220.38b91b.024e.GAE@google.com>
Date: Tue, 04 Mar 2025 21:33:33 -0800
From: syzbot <syzbot+20024c0fe2bf6dbc8c1e@...kaller.appspotmail.com>
To: akpm@...ux-foundation.org, linux-kernel@...r.kernel.org, 
	linux-mm@...ck.org, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [mm?] WARNING in depot_fetch_stack

Hello,

syzbot found the following issue on:

HEAD commit:    276f98efb64a Merge tag 'block-6.14-20250228' of git://git...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17a6c864580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5b4c41bdaeea1964
dashboard link: https://syzkaller.appspot.com/bug?extid=20024c0fe2bf6dbc8c1e
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-276f98ef.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5a036150d62e/vmlinux-276f98ef.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f0b6c8e5972f/bzImage-276f98ef.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+20024c0fe2bf6dbc8c1e@...kaller.appspotmail.com

loop0: detected capacity change from 0 to 32768
bcachefs (loop0): starting version 1.7: mi_btree_bitmap opts=metadata_checksum=none,data_checksum=none,compression=lz4,erasure_code,fsck,norecovery,nojournal_transaction_names,reconstruct_alloc,nocow,no_data_io
bcachefs (loop0): recovering from clean shutdown, journal seq 10
bcachefs (loop0): Version upgrade required:
Version upgrade from 0.24: unwritten_extents to 1.7: mi_btree_bitmap incomplete
Doing incompatible version upgrade from 0.24: unwritten_extents to 1.20: directory_size
  running recovery passes: check_allocations,check_alloc_info,check_lrus,check_btree_backpointers,check_backpointers_to_extents,check_extents_to_backpointers,check_alloc_to_lru_refs,bucket_gens_init,check_snapshot_trees,check_snapshots,check_subvols,check_subvol_children,delete_dead_snapshots,check_inodes,check_extents,check_indirect_extents,check_dirents,check_xattrs,check_root,check_unreachable_inodes,check_subvolume_structure,check_directory_structure,check_nlinks,set_fs_needs_rebalance
bcachefs (loop0): dropping and reconstructing all alloc info
bcachefs (loop0): error validating btree node on loop0 at btree xattrs level 0/0
  u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 2285c34bed0abe32 written 16 min_key POS_MIN durability: 1 ptr: 0:31:0 gen 0  
  node offset 0/16 bset u64s 60928: bset past end of btree node (offset 0 len 960 but written 16), exiting
bcachefs (loop0): Unable to continue, halting
bcachefs (loop0): flagging btree xattrs lost data
bcachefs (loop0): running explicit recovery pass check_topology (2), currently at recovery_pass_empty (0)
bcachefs (loop0): running explicit recovery pass scan_for_btree_nodes (1), currently at recovery_pass_empty (0)
error reading btree root btree=xattrs level=0: btree_node_read_error, fixing
invalid bkey in btree_node btree=subvolumes level=0: u64s 7 type subvolume 0:1:0 len 0 ver 0: root 4096 snapshot id 0
  invalid snapshot: delete?, fixing
bcachefs (loop0): scan_for_btree_nodes...
bcachefs (loop0): btree node scan found 7 nodes after overwrites
 done
bcachefs (loop0): check_topology...
bcachefs (loop0): btree root xattrs unreadable, must recover from scan
bcachefs (loop0): bch2_get_scanned_nodes(): recovery btree=xattrs level=0 POS_MIN - SPOS_MAX
bcachefs (loop0): bch2_get_scanned_nodes(): recovering u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 2285c34bed0abe32 written 960 min_key POS_MIN durability: 1 ptr: 0:31:0 gen 0
empty interior btree node at btree=xattrs level=1
u64s 5 type btree_ptr SPOS_MAX len 0 ver 0, fixing
bcachefs (loop0): empty btree root xattrs
 done
bcachefs (loop0): accounting_read... done
bcachefs (loop0): alloc_read... done
bcachefs (loop0): stripes_read... done
bcachefs (loop0): snapshots_read... done
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5318 at lib/stackdepot.c:461 depot_fetch_stack+0x9c/0xc0 lib/stackdepot.c:461
Modules linked in:
CPU: 0 UID: 0 PID: 5318 Comm: syz.0.0 Not tainted 6.14.0-rc4-syzkaller-00212-g276f98efb64a #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:depot_fetch_stack+0x9c/0xc0 lib/stackdepot.c:461
Code: 48 c7 c7 de fa 3a 8e 89 ee 44 89 f2 89 d9 e8 ab eb 53 fc 90 0f 0b 90 90 31 c0 5b 41 5e 5d c3 cc cc cc cc 90 0f 0b 90 eb ef 90 <0f> 0b 90 eb e9 48 c7 c7 30 af 2b 8f 4c 89 f6 e8 50 67 00 00 eb 94
RSP: 0018:ffffc900019a71e0 EFLAGS: 00010246
RAX: ffff888044008000 RBX: 00000000000036b0 RCX: 0000000000100000
RDX: ffffc9000e64a000 RSI: ffffffff8c2ab700 RDI: ffffffff8c80f060
RBP: 000000000000025f R08: ffffffff82329a83 R09: 1ffffffff2079dee
R10: dffffc0000000000 R11: fffffbfff2079def R12: 0000000000000001
R13: dffffc0000000000 R14: 000000000000025f R15: 0000000006d60260
FS:  00007f3e5c1916c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555f8aa8e098 CR3: 000000003843c000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 dec_stack_record_count mm/page_owner.c:222 [inline]
 __reset_page_owner+0x320/0x430 mm/page_owner.c:310
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660
 discard_slab mm/slub.c:2684 [inline]
 __put_partials+0x160/0x1c0 mm/slub.c:3153
 put_cpu_partial+0x17c/0x250 mm/slub.c:3228
 __slab_free+0x290/0x380 mm/slub.c:4479
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4115 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 __do_kmalloc_node mm/slub.c:4293 [inline]
 __kmalloc_node_noprof+0x23c/0x4d0 mm/slub.c:4300
 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:662
 __bch2_darray_resize_noprof+0xd2/0x290 fs/bcachefs/darray.c:24
 bch2_write_super+0x48a/0x3cd0 fs/bcachefs/super-io.c:997
 __bch2_check_set_feature+0xe6/0x150 fs/bcachefs/super-io.c:1180
 bch2_check_set_feature fs/bcachefs/super-io.h:106 [inline]
 bch2_opt_check_may_set fs/bcachefs/opts.c:489 [inline]
 bch2_opts_check_may_set+0xf2/0x150 fs/bcachefs/opts.c:502
 bch2_fs_start+0x3be/0x610 fs/bcachefs/super.c:1048
 bch2_fs_get_tree+0xdb7/0x17a0 fs/bcachefs/fs.c:2203
 vfs_get_tree+0x90/0x2b0 fs/super.c:1814
 do_new_mount+0x2be/0xb40 fs/namespace.c:3560
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
 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: 0033:0x7f3e5b38e90a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3e5c190e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f3e5c190ef0 RCX: 00007f3e5b38e90a
RDX: 00004000000058c0 RSI: 0000400000005900 RDI: 00007f3e5c190eb0
RBP: 00004000000058c0 R08: 00007f3e5c190ef0 R09: 0000000000010000
R10: 0000000000010000 R11: 0000000000000246 R12: 0000400000005900
R13: 00007f3e5c190eb0 R14: 0000000000005912 R15: 00004000000001c0
 </TASK>


---
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