[syzbot] [pci?] upstream test error: BUG: unable to handle kernel NULL pointer dereference in msix_prepare_msi_desc

[syzbot <syzbot+9c23146ed23f4a1be6d1@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    f6e0150b2003 Merge tag 'mtd/for-6.15' of git://git.kernel...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=161dd43f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5484680e4cf4b356
dashboard link: https://syzkaller.appspot.com/bug?extid=9c23146ed23f4a1be6d1
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b6dd1dc395cb/disk-f6e0150b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d374849a451e/vmlinux-f6e0150b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1cae448b43cd/bzImage-f6e0150b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9c23146ed23f4a1be6d1@syzkaller.appspotmail.com

ntfs3: Enabled Linux POSIX ACLs support
ntfs3: Read-only LZX/Xpress compression included
efs: 1.0a - http://aeschi.ch.eu.org/efs/
jffs2: version 2.2. (NAND) (SUMMARY)  © 2001-2006 Red Hat, Inc.
romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
QNX4 filesystem 0.2.3 registered.
qnx6: QNX6 filesystem 1.0.0 registered.
fuse: init (API version 7.42)
orangefs_debugfs_init: called with debug mask: :none: :0:
orangefs_init: module version upstream loaded
JFS: nTxBlock = 8192, nTxLock = 65536
SGI XFS with ACLs, security attributes, realtime, quota, no debug enabled
9p: Installing v9fs 9p2000 file system support
NILFS version 2 loaded
befs: version: 0.9.3
ocfs2: Registered cluster interface o2cb
ocfs2: Registered cluster interface user
OCFS2 User DLM kernel interface loaded
gfs2: GFS2 installed
ceph: loaded (mds proto 32)
NET: Registered PF_ALG protocol family
xor: automatically using best checksumming function   avx       
async_tx: api initialized (async)
Key type asymmetric registered
Asymmetric key parser 'x509' registered
Asymmetric key parser 'pkcs8' registered
Key type pkcs7_test registered
Block layer SCSI generic (bsg) driver version 0.4 loaded (major 238)
io scheduler mq-deadline registered
io scheduler kyber registered
io scheduler bfq registered
input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input0
ACPI: button: Power Button [PWRF]
input: Sleep Button as /devices/LNXSYSTM:00/LNXSLPBN:00/input/input1
ACPI: button: Sleep Button [SLPF]
ioatdma: Intel(R) QuickData Technology Driver 5.00
ACPI: \_SB_.LNKC: Enabled at IRQ 11
virtio-pci 0000:00:03.0: virtio_pci: leaving for legacy driver
ACPI: \_SB_.LNKD: Enabled at IRQ 10
virtio-pci 0000:00:04.0: virtio_pci: leaving for legacy driver
ACPI: \_SB_.LNKB: Enabled at IRQ 10
virtio-pci 0000:00:06.0: virtio_pci: leaving for legacy driver
virtio-pci 0000:00:07.0: virtio_pci: leaving for legacy driver
N_HDLC line discipline registered with maxframe=4096
Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
00:03: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
00:04: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A
00:05: ttyS2 at I/O 0x3e8 (irq = 6, base_baud = 115200) is a 16550A
00:06: ttyS3 at I/O 0x2e8 (irq = 7, base_baud = 115200) is a 16550A
Non-volatile memory driver v1.3
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0 
Oops: Oops: 0000 [#1] SMP PTI
CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.14.0-syzkaller-03565-gf6e0150b2003 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:msix_prepare_msi_desc+0x46/0xc0 drivers/pci/msi/msi.c:615
Code: 02 00 00 31 ff 48 8b 40 20 66 81 4b 54 01 01 c7 43 04 01 00 00 00 8b 95 ac 03 00 00 89 53 58 4c 8b a5 a0 09 00 00 4c 89 63 60 <8b> 28 81 e5 00 00 40 00 89 ee e8 1b 62 9f fe 85 ed 75 1c e8 c2 69
RSP: 0000:ffffc9000005b988 EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffffc9000005b9d0 RCX: ffffffff82c27691
RDX: 000000000000000b RSI: ffffffff82c27508 RDI: 0000000000000000
RBP: ffff88814047a000 R08: 0000000000000004 R09: 0000000000000000
R10: 0000000000000002 R11: ffffffff83293622 R12: ffffc90000085008
R13: 0000000000000000 R14: ffffc9000005b9d0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881b26e8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000006c62000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 msix_setup_msi_descs+0xf3/0x190 drivers/pci/msi/msi.c:639
 __msix_setup_interrupts drivers/pci/msi/msi.c:672 [inline]
 msix_setup_interrupts drivers/pci/msi/msi.c:701 [inline]
 msix_capability_init drivers/pci/msi/msi.c:743 [inline]
 __pci_enable_msix_range+0x55a/0x9b0 drivers/pci/msi/msi.c:851
 pci_alloc_irq_vectors_affinity+0x18b/0x1f0 drivers/pci/msi/api.c:268
 vp_request_msix_vectors drivers/virtio/virtio_pci_common.c:160 [inline]
 vp_find_vqs_msix+0x28e/0x710 drivers/virtio/virtio_pci_common.c:417
 vp_find_vqs+0x4a/0x3c0 drivers/virtio/virtio_pci_common.c:525
 virtio_find_vqs include/linux/virtio_config.h:226 [inline]
 virtio_find_single_vq include/linux/virtio_config.h:237 [inline]
 probe_common+0x12e/0x2b0 drivers/char/hw_random/virtio-rng.c:155
 virtio_dev_probe+0x305/0x430 drivers/virtio/virtio.c:341
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x12c/0x430 drivers/base/dd.c:658
 __driver_probe_device+0xc3/0x1a0 drivers/base/dd.c:800
 driver_probe_device+0x2a/0x120 drivers/base/dd.c:830
 __driver_attach drivers/base/dd.c:1216 [inline]
 __driver_attach+0x10e/0x200 drivers/base/dd.c:1156
 bus_for_each_dev+0xb2/0x110 drivers/base/bus.c:370
 bus_add_driver+0x122/0x2e0 drivers/base/bus.c:678
 driver_register+0x85/0x180 drivers/base/driver.c:249
 do_one_initcall+0x74/0x480 init/main.c:1257
 do_initcall_level init/main.c:1319 [inline]
 do_initcalls init/main.c:1335 [inline]
 do_basic_setup init/main.c:1354 [inline]
 kernel_init_freeable+0x251/0x450 init/main.c:1567
 kernel_init+0x1b/0x2a0 init/main.c:1457
 ret_from_fork+0x45/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:msix_prepare_msi_desc+0x46/0xc0 drivers/pci/msi/msi.c:615
Code: 02 00 00 31 ff 48 8b 40 20 66 81 4b 54 01 01 c7 43 04 01 00 00 00 8b 95 ac 03 00 00 89 53 58 4c 8b a5 a0 09 00 00 4c 89 63 60 <8b> 28 81 e5 00 00 40 00 89 ee e8 1b 62 9f fe 85 ed 75 1c e8 c2 69
RSP: 0000:ffffc9000005b988 EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffffc9000005b9d0 RCX: ffffffff82c27691
RDX: 000000000000000b RSI: ffffffff82c27508 RDI: 0000000000000000
RBP: ffff88814047a000 R08: 0000000000000004 R09: 0000000000000000
R10: 0000000000000002 R11: ffffffff83293622 R12: ffffc90000085008
R13: 0000000000000000 R14: ffffc9000005b9d0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881b26e8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000006c62000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	02 00                	add    (%rax),%al
   2:	00 31                	add    %dh,(%rcx)
   4:	ff 48 8b             	decl   -0x75(%rax)
   7:	40 20 66 81          	and    %spl,-0x7f(%rsi)
   b:	4b 54                	rex.WXB push %r12
   d:	01 01                	add    %eax,(%rcx)
   f:	c7 43 04 01 00 00 00 	movl   $0x1,0x4(%rbx)
  16:	8b 95 ac 03 00 00    	mov    0x3ac(%rbp),%edx
  1c:	89 53 58             	mov    %edx,0x58(%rbx)
  1f:	4c 8b a5 a0 09 00 00 	mov    0x9a0(%rbp),%r12
  26:	4c 89 63 60          	mov    %r12,0x60(%rbx)
* 2a:	8b 28                	mov    (%rax),%ebp <-- trapping instruction
  2c:	81 e5 00 00 40 00    	and    $0x400000,%ebp
  32:	89 ee                	mov    %ebp,%esi
  34:	e8 1b 62 9f fe       	call   0xfe9f6254
  39:	85 ed                	test   %ebp,%ebp
  3b:	75 1c                	jne    0x59
  3d:	e8                   	.byte 0xe8
  3e:	c2                   	.byte 0xc2
  3f:	69                   	.byte 0x69


---
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