From: Dan Carpenter Date: Mon, 14 Jun 2021 09:55:35 +0000 (+0300) Subject: staging: gdm724x: check for buffer overflow in gdm_lte_multi_sdu_pkt() X-Git-Tag: v5.15.73~11621^2~145 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4a36e160856db8a8ddd6a3d2e5db5a850ab87f82;p=platform%2Fkernel%2Flinux-rpi.git staging: gdm724x: check for buffer overflow in gdm_lte_multi_sdu_pkt() 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 Link: https://lore.kernel.org/r/YMcnl4zCwGWGDVMG@mwanda Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/gdm724x/gdm_lte.c b/drivers/staging/gdm724x/gdm_lte.c index ad9ed3df9fcf..d4dfaead25da 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; @@ -687,6 +688,12 @@ 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); @@ -697,7 +704,8 @@ 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; }