Re: [syzbot] [media?] [dri?] WARNING in udmabuf_create
From: syzbot
Date: Wed Aug 26 2026 - 06:15:26 EST
syzbot has found a reproducer for the following issue on:
HEAD commit: 73ae59e97596 Merge tag 'erofs-for-7.3-rc1-2' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12dff979580000
kernel config: https://syzkaller.appspot.com/x/.config?x=8d423d3e91ba4f47
dashboard link: https://syzkaller.appspot.com/bug?extid=bfeed181d1ce9ec87a8f
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
userspace arch: i386
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16d50d49580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11296979580000
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-73ae59e9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2edc303b5fba/vmlinux-73ae59e9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2624d8e0a8af/bzImage-73ae59e9.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bfeed181d1ce9ec87a8f@xxxxxxxxxxxxxxxxxxxxxxxxx
------------[ cut here ]------------
!(flags & __GFP_NOWARN)
WARNING: mm/slub.c:7013 at __kvmalloc_node_noprof+0x646/0x9b0 mm/slub.c:7013, CPU#2: syz.0.17/5920
Modules linked in:
CPU: 2 UID: 0 PID: 5920 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__kvmalloc_node_noprof+0x646/0x9b0 mm/slub.c:7013
Code: c1 e8 2e 07 ff ff 4d 85 f6 0f 85 b6 fd ff ff 48 81 fb ff ff ff 7f 0f 86 4d fd ff ff 41 81 e4 00 20 00 00 0f 85 9c fd ff ff 90 <0f> 0b 90 e9 93 fd ff ff 41 be 10 00 00 00 e9 88 fd ff ff be 42 01
RSP: 0018:ffffc90003d8fb50 EFLAGS: 00010246
RAX: 0000000000000001 RBX: 0000008000800018 RCX: 0000010000000000
RDX: 0000000000000000 RSI: ffffffff8c61e200 RDI: ffffffff8e6ad930
RBP: 0000000008000800 R08: 00000000000028c0 R09: 00000000ffffffff
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 00000000000028c0 R14: 0000000000000000 R15: 00000000ffffffff
FS: 0000000000000000(0000) GS:ffff888096b76000(0063) knlGS:00000000579e1480
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f7113140 CR3: 00000000542cb000 CR4: 0000000000352ef0
Call Trace:
<TASK>
init_udmabuf drivers/dma-buf/udmabuf.c:193 [inline]
udmabuf_create+0x2e8/0x12a0 drivers/dma-buf/udmabuf.c:386
udmabuf_ioctl_create_list drivers/dma-buf/udmabuf.c:484 [inline]
udmabuf_ioctl+0x2b2/0x300 drivers/dma-buf/udmabuf.c:499
__do_compat_sys_ioctl fs/ioctl.c:695 [inline]
__se_compat_sys_ioctl fs/ioctl.c:638 [inline]
__ia32_compat_sys_ioctl+0x2cf/0x360 fs/ioctl.c:638
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
__do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291
do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f03fec
Code: Unable to access opcode bytes at 0xf7f03fc2.
RSP: 002b:00000000ffe2d40c EFLAGS: 00000292 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000040087543
RDX: 0000000080000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</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.