Re: [syzbot] [target?] WARNING in rd_configure_device

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

syzbot has found a reproducer for the following issue on:

HEAD commit:    eea3fef32a9c Add linux-next specific files for 20261006
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1717fff5580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=36aaffb2bd6a0a93
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
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1097fff5580000

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:5459 at ___kmalloc_large_node+0x10c/0x170 mm/slub.c:5459, CPU#0: syz-executor320/5981
Modules linked in:
CPU: 0 UID: 0 PID: 5981 Comm: syz-executor320 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:___kmalloc_large_node+0x10c/0x170 mm/slub.c:5459
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 5c ca 0b 00 c6 05 b8 ae 76 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:ffffc90003287a88 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000004000000 RCX: 0000000000000000
RDX: 00000000ffffffff RSI: 0000000000000dc0 RDI: 0000000004000000
RBP: 0000000000000dc0 R08: ffffc90003287b47 R09: 1ffff92000650f68
R10: dffffc0000000000 R11: ffffffff86a6d4d0 R12: dffffc0000000000
R13: ffffffff86a6d5d9 R14: 0000000004000000 R15: 1ffff11006d1a2c3
FS:  000055558e991400(0000) GS:ffff888124633000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005560dd7ca000 CR3: 000000002755e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __kmalloc_large_node_noprof+0x18/0x90 mm/slub.c:5502
 __do_kmalloc_node mm/slub.c:5519 [inline]
 __kmalloc_noprof+0x3f6/0x710 mm/slub.c:5556
 _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: 0033:0x7f3f2d0cd537
Code: 48 89 fa 4c 89 df e8 98 1d 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffe88432110 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055558e991400 RCX: 00007f3f2d0cd537
RDX: 0000000000000002 RSI: 00007f3f2d1060c3 RDI: 0000000000000003
RBP: 00007f3f2d108320 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007f3f2d1060c3
R13: 0000000000000002 R14: 00007f3f2d130cc0 R15: 0000000000000002
 </TASK>


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.