[syzbot] [bluetooth?] KMSAN: uninit-value in hci_cmd_complete_evt

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    2d5404caa8c7 Linux 6.12-rc7
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1357fe30580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=dcca673786a14715
dashboard link: https://syzkaller.appspot.com/bug?extid=a9a4bedfca6aa9d7fa24
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a2910755fac8/disk-2d5404ca.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a135257837ee/vmlinux-2d5404ca.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3f8930906164/bzImage-2d5404ca.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a9a4bedfca6aa9d7fa24@xxxxxxxxxxxxxxxxxxxxxxxxx

=====================================================
BUG: KMSAN: uninit-value in hci_cmd_complete_evt+0xd7b/0xeb0 net/bluetooth/hci_event.c:4221
 hci_cmd_complete_evt+0xd7b/0xeb0 net/bluetooth/hci_event.c:4221
 hci_event_func net/bluetooth/hci_event.c:7440 [inline]
 hci_event_packet+0x11df/0x1c20 net/bluetooth/hci_event.c:7495
 hci_rx_work+0x9d1/0x11f0 net/bluetooth/hci_core.c:4031
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310
 worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391
 kthread+0x3e2/0x540 kernel/kthread.c:389
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was stored to memory at:
 hci_cmd_complete_evt+0xaf4/0xeb0
 hci_event_func net/bluetooth/hci_event.c:7440 [inline]
 hci_event_packet+0x11df/0x1c20 net/bluetooth/hci_event.c:7495
 hci_rx_work+0x9d1/0x11f0 net/bluetooth/hci_core.c:4031
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310
 worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391
 kthread+0x3e2/0x540 kernel/kthread.c:389
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4091 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4186
 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:587
 __alloc_skb+0x363/0x7b0 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1322 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:494 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:487 [inline]
 vhci_write+0x127/0x900 drivers/bluetooth/hci_vhci.c:607
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0xb2b/0x1540 fs/read_write.c:683
 ksys_write+0x24f/0x4c0 fs/read_write.c:736
 __do_sys_write fs/read_write.c:748 [inline]
 __se_sys_write fs/read_write.c:745 [inline]
 __x64_sys_write+0x93/0xe0 fs/read_write.c:745
 x64_sys_call+0x306a/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 5791 Comm: kworker/u9:2 Not tainted 6.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Workqueue: hci1 hci_rx_work
=====================================================


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