KMSAN: uninit-value in hci_recv

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-5.15	KASAN: use-after-free Read in hci_recv_frame	19				9	374d	509d	0/3	auto-obsoleted due to no activity on 2025/02/06 13:33
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BUG: KMSAN: uninit-value in hci_conn_lookup_type include/net/bluetooth/hci_core.h:1126 [inline]
BUG: KMSAN: uninit-value in hci_recv_frame+0x550/0x7d0 net/bluetooth/hci_core.c:2944
 hci_conn_lookup_type include/net/bluetooth/hci_core.h:1126 [inline]
 hci_recv_frame+0x550/0x7d0 net/bluetooth/hci_core.c:2944
 vhci_get_user drivers/bluetooth/hci_vhci.c:512 [inline]
 vhci_write+0x568/0x960 drivers/bluetooth/hci_vhci.c:608
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0xbe2/0x15d0 fs/read_write.c:686
 ksys_write fs/read_write.c:738 [inline]
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __x64_sys_write+0x1fb/0x4d0 fs/read_write.c:746
 x64_sys_call+0x3014/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4186 [inline]
 slab_alloc_node mm/slub.c:4229 [inline]
 kmem_cache_alloc_node_noprof+0x818/0xf00 mm/slub.c:4281
 kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:578
 __alloc_skb+0x347/0x7d0 net/core/skbuff.c:669
 alloc_skb include/linux/skbuff.h:1336 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:509 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:488 [inline]
 vhci_write+0x125/0x960 drivers/bluetooth/hci_vhci.c:608
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0xbe2/0x15d0 fs/read_write.c:686
 ksys_write fs/read_write.c:738 [inline]
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __x64_sys_write+0x1fb/0x4d0 fs/read_write.c:746
 x64_sys_call+0x3014/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 13051 Comm: syz.6.1984 Not tainted syzkaller #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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