Subject: [syzbot] [bpf?] linux-next test error: WARNING: kmalloc bug in bpf_prog_alloc_no_stats

From: syzbot <[email-masked]>
Date: Fri, 21 Nov 2025 20:50:21 -0800

Hello,

syzbot found the following issue on:

HEAD commit:    187dac290bfd Add linux-next specific files for 20251118
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13803212580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f3aa05e175a53177
dashboard link: https://syzkaller.appspot.com/bug?extid=48df175b68984f0d4198
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5c9f9e2c17d9/disk-187dac29.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/abf1aa794deb/vmlinux-187dac29.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3e5ce6fc9bfd/bzImage-187dac29.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

------------[ cut here ]------------
Unexpected gfp: 0x400000 (__GFP_ACCOUNT). Fixing up to gfp: 0xdc0 (GFP_KERNEL|__GFP_ZERO). Fix your code!
WARNING: mm/vmalloc.c:3938 at vmalloc_fix_flags+0x9c/0xe0 mm/vmalloc.c:3937, CPU#1: syz-executor/6175
Modules linked in:
CPU: 1 UID: 0 PID: 6175 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:vmalloc_fix_flags+0x9c/0xe0 mm/vmalloc.c:3937
Code: 81 e6 1f 52 ee ff 89 74 24 30 81 e3 e0 ad 11 00 89 5c 24 20 90 48 c7 c7 e0 db 96 8b 4c 89 fa 89 d9 4d 89 f0 e8 75 8d 6c ff 90 <0f> 0b 90 90 8b 44 24 20 48 c7 04 24 0e 36 e0 45 4b c7 04 2c 00 00
RSP: 0018:ffffc90005107b00 EFLAGS: 00010246
RAX: 9deb18dd39b86e00 RBX: 0000000000000dc0 RCX: ffff888079fadb80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc90005107b98 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1c3a708 R12: 1ffff92000a20f60
R13: dffffc0000000000 R14: ffffc90005107b20 R15: ffffc90005107b30
FS:  000055557fbce500(0000) GS:ffff888125b74000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f171365c470 CR3: 0000000076216000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __vmalloc_noprof+0xf2/0x120 mm/vmalloc.c:4124
 bpf_prog_alloc_no_stats+0x4a/0x4d0 kernel/bpf/core.c:106
 bpf_prog_alloc+0x3c/0x1a0 kernel/bpf/core.c:153
 bpf_prog_create_from_user+0xa7/0x440 net/core/filter.c:1443
 seccomp_prepare_filter kernel/seccomp.c:701 [inline]
 seccomp_prepare_user_filter kernel/seccomp.c:738 [inline]
 seccomp_set_mode_filter kernel/seccomp.c:1990 [inline]
 do_seccomp+0x7b1/0xd90 kernel/seccomp.c:2110
 __do_sys_prctl kernel/sys.c:2610 [inline]
 __se_sys_prctl+0xc3c/0x1830 kernel/sys.c:2518
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1713790b0d
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 18 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 9d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 1b 48 8b 54 24 18 64 48 2b 14 25 28 00 00 00
RSP: 002b:00007fffcecd72f0 EFLAGS: 00000246 ORIG_RAX: 000000000000009d
RAX: ffffffffffffffda RBX: 00007f171382cf80 RCX: 00007f1713790b0d
RDX: 00007fffcecd7350 RSI: 0000000000000002 RDI: 0000000000000016
RBP: 00007fffcecd7360 R08: 0000000000000006 R09: 0000000000000071
R10: 0000000000000071 R11: 0000000000000246 R12: 000000000000006d
R13: 00007fffcecd7788 R14: 00007fffcecd7a08 R15: 0000000000000000
 </TASK>

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