[syzbot] [target?] WARNING in rd_configure_device

[syzbot <syzbot+fa495e1497c48a6ed885@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    9d80aa4617b3 Add linux-next specific files for 20260903
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13c1dbf9580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b370c26fb58c72f0
dashboard link: https://syzkaller.appspot.com/bug?extid=fa495e1497c48a6ed885
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/84a12994f553/disk-9d80aa46.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2329deeb3b2b/vmlinux-9d80aa46.xz
kernel image: https://storage.googleapis.com/syzbot-assets/689910d8c695/bzImage-9d80aa46.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fa495e1497c48a6ed885@syzkaller.appspotmail.com

------------[ cut here ]------------
1
WARNING: mm/slub.c:5347 at ___kmalloc_large_node+0x10c/0x170 mm/slub.c:5347, CPU#1: syz.3.40/5899
Modules linked in:
CPU: 1 UID: 0 PID: 5899 Comm: syz.3.40 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:___kmalloc_large_node+0x10c/0x170 mm/slub.c:5347
Code: 41 c7 46 30 00 00 00 f8 eb 03 45 31 ff 4c 89 ff 48 89 de 89 ea 5b 41 5c 41 5e 41 5f 5d e9 8c a0 0b 00 c6 05 8e e4 58 0e 01 90 <0f> 0b 90 31 c0 5b 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 89 ef 89
RSP: 0018:ffffc90004b7fa88 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000008000000 RCX: ffff8880237eddc0
RDX: 00000000ffffffff RSI: 0000000000000dc0 RDI: 0000000008000000
RBP: 0000000000000dc0 R08: ffffc90004b7fb47 R09: 1ffff9200096ff68
R10: dffffc0000000000 R11: ffffffff869fe6a0 R12: dffffc0000000000
R13: ffffffff869fe7a9 R14: 0000000008000000 R15: 1ffff1100eff52c3
FS:  00007f0d2de8e6c0(0000) GS:ffff88812495b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c470003 CR3: 0000000036170000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __kmalloc_large_node_noprof+0x18/0x90 mm/slub.c:5390
 __do_kmalloc_node mm/slub.c:5407 [inline]
 __kmalloc_noprof+0x3f6/0x710 mm/slub.c:5444
 _kmalloc_noprof include/linux/slab.h:995 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 rd_build_device_space drivers/target/target_core_rd.c:194 [inline]
 rd_configure_device+0x109/0x730 drivers/target/target_core_rd.c:294
 target_configure_device+0x13c/0xa70 drivers/target/target_core_device.c:988
 target_dev_enable_store+0x3e/0x80 drivers/target/target_core_configfs.c:2484
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x337/0x430 fs/configfs/file.c:229
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0d2cf9e159
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:00007f0d2de8e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0d2d225fa0 RCX: 00007f0d2cf9e159
RDX: 0000000000000002 RSI: 0000200000000280 RDI: 0000000000000004
RBP: 00007f0d2d03506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0d2d226038 R14: 00007f0d2d225fa0 R15: 00007ffe861d7d28
 </TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup