[syzbot] [net?] WARNING in new_slab (3)

[syzbot] [net?] WARNING in new_slab (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    6f8319e3e9a4 Merge tag 'mm-hotfixes-stable-2026-09-27-19-1..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13af7df5580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2a820d8842c77560
dashboard link: https://syzkaller.appspot.com/bug?extid=f95c2f0a71a98cef50eb
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
userspace arch: i386

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-6f8319e3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/91b951779fc3/vmlinux-6f8319e3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/18319ae672c1/bzImage-6f8319e3.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f95c2f0a71a98cef50eb@syzkaller.appspotmail.com

------------[ cut here ]------------
current->flags & PF_MEMALLOC
WARNING: mm/page_alloc.c:4816 at __alloc_pages_slowpath mm/page_alloc.c:4816 [inline], CPU#0: cifsd/12032
WARNING: mm/page_alloc.c:4816 at __alloc_frozen_pages_noprof+0x1eac/0x3300 mm/page_alloc.c:5449, CPU#0: cifsd/12032
Modules linked in:
CPU: 0 UID: 0 PID: 12032 Comm: cifsd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__alloc_pages_slowpath mm/page_alloc.c:4816 [inline]
RIP: 0010:__alloc_frozen_pages_noprof+0x1eac/0x3300 mm/page_alloc.c:5449
Code: 38 d0 7c 08 84 d2 0f 85 de 12 00 00 65 48 8b 05 e2 a7 1c 12 c7 84 24 94 00 00 00 00 80 00 00 f6 40 2d 08 0f 84 ba e7 ff ff 90 <0f> 0b 90 e9 b1 e7 ff ff 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03
RSP: 0000:ffffc90002e172d0 EFLAGS: 00010202
RAX: ffff888029380000 RBX: 0000000000000000 RCX: 1ffff1100fffad29
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff88803fffd938
RBP: ffff88802938002c R08: 0000000000008000 R09: 0000000000000001
R10: 0000000000000002 R11: 0000000000000000 R12: 00000000000cac40
R13: ffff88803fffb900 R14: 0000000000000000 R15: 1ffff920005c2e74
FS:  0000000000000000(0000) GS:ffff888096955000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000008000a000 CR3: 00000000403b5000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab mm/slub.c:3470 [inline]
 new_slab+0x1f6/0x6e0 mm/slub.c:3513
 refill_objects+0xe3/0x410 mm/slub.c:7417
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 ref_tracker_alloc+0x190/0x590 lib/ref_tracker.c:270
 __netns_tracker_alloc include/net/net_namespace.h:370 [inline]
 sk_alloc+0xcfc/0xe80 net/core/sock.c:2329
 inet_create net/ipv4/af_inet.c:333 [inline]
 inet_create+0x3a0/0x1060 net/ipv4/af_inet.c:259
 __sock_create+0x339/0x860 net/socket.c:1676
 generic_ip_connect+0x826/0x1810 fs/smb/client/connect.c:3377
 __cifs_reconnect+0x348/0xa80 fs/smb/client/connect.c:420
 _cifs_reconnect fs/smb/client/connect.c:596 [inline]
 cifs_reconnect fs/smb/client/connect.c:610 [inline]
 cifs_readv_from_socket+0x7c1/0xa30 fs/smb/client/connect.c:749
 cifs_read_from_socket+0xb8/0x100 fs/smb/client/connect.c:804
 cifs_demultiplex_thread+0x2db/0x2ea0 fs/smb/client/connect.c:1295
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>


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