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authorKees Cook <keescook@chromium.org>2023-10-11 18:31:44 +0200
committerLuiz Augusto von Dentz <luiz.von.dentz@intel.com>2023-10-14 05:06:33 +0200
commitcb3871b1cd135a6662b732fbc6b3db4afcdb4a64 (patch)
treef4e8dd8b980bc0db25584aa38626127c1ff20183 /net/bluetooth
parentBluetooth: avoid memcmp() out of bounds warning (diff)
downloadlinux-cb3871b1cd135a6662b732fbc6b3db4afcdb4a64.tar.xz
linux-cb3871b1cd135a6662b732fbc6b3db4afcdb4a64.zip
Bluetooth: hci_sock: Correctly bounds check and pad HCI_MON_NEW_INDEX name
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@intel.com> Cc: Edward AD <twuufnxlz@gmail.com> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: linux-bluetooth@vger.kernel.org Cc: netdev@vger.kernel.org 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@chromium.org> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Diffstat (limited to 'net/bluetooth')
-rw-r--r--net/bluetooth/hci_sock.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index 72abe54c45dd..3e7cd330d731 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -488,7 +488,8 @@ static struct sk_buff *create_monitor_event(struct hci_dev *hdev, int event)
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;