This is a note to let you know that I've just added the patch titled staging: gdm724x: check for buffer overflow in gdm_lte_multi_sdu_pkt() to the 5.13-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: staging-gdm724x-check-for-buffer-overflow-in-gdm_lte.patch and it can be found in the queue-5.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit bf44a6b0c3b38e9bdf2f5fba7bf595e3c3f38255 Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Date: Mon Jun 14 12:55:35 2021 +0300 staging: gdm724x: check for buffer overflow in gdm_lte_multi_sdu_pkt() [ Upstream commit 4a36e160856db8a8ddd6a3d2e5db5a850ab87f82 ] There needs to be a check to verify that we don't read beyond the end of "buf". This function is called from do_rx(). The "buf" is the USB transfer_buffer and "len" is "urb->actual_length". Fixes: 61e121047645 ("staging: gdm7240: adding LTE USB driver") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Link: https://lore.kernel.org/r/YMcnl4zCwGWGDVMG@mwanda Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/staging/gdm724x/gdm_lte.c b/drivers/staging/gdm724x/gdm_lte.c index 571f47d39484..a41af7aa74ec 100644 --- a/drivers/staging/gdm724x/gdm_lte.c +++ b/drivers/staging/gdm724x/gdm_lte.c @@ -677,6 +677,7 @@ static void gdm_lte_multi_sdu_pkt(struct phy_dev *phy_dev, char *buf, int len) struct sdu *sdu = NULL; u8 endian = phy_dev->get_endian(phy_dev->priv_dev); u8 *data = (u8 *)multi_sdu->data; + int copied; u16 i = 0; u16 num_packet; u16 hci_len; @@ -688,6 +689,12 @@ static void gdm_lte_multi_sdu_pkt(struct phy_dev *phy_dev, char *buf, int len) num_packet = gdm_dev16_to_cpu(endian, multi_sdu->num_packet); for (i = 0; i < num_packet; i++) { + copied = data - multi_sdu->data; + if (len < copied + sizeof(*sdu)) { + pr_err("rx prevent buffer overflow"); + return; + } + sdu = (struct sdu *)data; cmd_evt = gdm_dev16_to_cpu(endian, sdu->cmd_evt); @@ -698,7 +705,8 @@ static void gdm_lte_multi_sdu_pkt(struct phy_dev *phy_dev, char *buf, int len) pr_err("rx sdu wrong hci %04x\n", cmd_evt); return; } - if (hci_len < 12) { + if (hci_len < 12 || + len < copied + sizeof(*sdu) + (hci_len - 12)) { pr_err("rx sdu invalid len %d\n", hci_len); return; }