This is a note to let you know that I've just added the patch titled
Bluetooth: hci_sock: Correctly bounds check and pad HCI_MON_NEW_INDEX name
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bluetooth-hci_sock-correctly-bounds-check-and-pad-hci_mon_new_index-name.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cb3871b1cd135a6662b732fbc6b3db4afcdb4a64 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@xxxxxxxxxxxx>
Date: Wed, 11 Oct 2023 09:31:44 -0700
Subject: Bluetooth: hci_sock: Correctly bounds check and pad HCI_MON_NEW_INDEX name
From: Kees Cook <keescook@xxxxxxxxxxxx>
commit cb3871b1cd135a6662b732fbc6b3db4afcdb4a64 upstream.
The code pattern of memcpy(dst, src, strlen(src)) is almost always
wrong. In this case it is wrong because it leaves memory uninitialized
if it is less than sizeof(ni->name), and overflows ni->name when longer.
Normally strtomem_pad() could be used here, but since ni->name is a
trailing array in struct hci_mon_new_index, compilers that don't support
-fstrict-flex-arrays=3 can't tell how large this array is via
__builtin_object_size(). Instead, open-code the helper and use sizeof()
since it will work correctly.
Additionally mark ni->name as __nonstring since it appears to not be a
%NUL terminated C string.
Cc: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Cc: Edward AD <twuufnxlz@xxxxxxxxx>
Cc: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Cc: Johan Hedberg <johan.hedberg@xxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: linux-bluetooth@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Fixes: 18f547f3fc07 ("Bluetooth: hci_sock: fix slab oob read in create_monitor_event")
Link: https://lore.kernel.org/lkml/202310110908.F2639D3276@keescook/
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/net/bluetooth/hci_mon.h | 2 +-
net/bluetooth/hci_sock.c | 3 ++-
2 files changed, 3 insertions(+), 2 deletions(-)
--- a/include/net/bluetooth/hci_mon.h
+++ b/include/net/bluetooth/hci_mon.h
@@ -54,7 +54,7 @@ struct hci_mon_new_index {
__u8 type;
__u8 bus;
bdaddr_t bdaddr;
- char name[8];
+ char name[8] __nonstring;
} __packed;
#define HCI_MON_NEW_INDEX_SIZE 16
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -430,7 +430,8 @@ static struct sk_buff *create_monitor_ev
ni->type = hdev->dev_type;
ni->bus = hdev->bus;
bacpy(&ni->bdaddr, &hdev->bdaddr);
- memcpy(ni->name, hdev->name, strlen(hdev->name));
+ memcpy_and_pad(ni->name, sizeof(ni->name), hdev->name,
+ strnlen(hdev->name, sizeof(ni->name)), '\0');
opcode = cpu_to_le16(HCI_MON_NEW_INDEX);
break;
Patches currently in stable-queue which might be from keescook@xxxxxxxxxxxx are
queue-5.4/bluetooth-hci_sock-correctly-bounds-check-and-pad-hci_mon_new_index-name.patch
queue-5.4/bluetooth-avoid-memcmp-out-of-bounds-warning.patch
queue-5.4/sky2-make-sure-there-is-at-least-one-frag_addr-avail.patch
