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: v4.4.276~104 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=38341d1a43a8810a093da0cb82e524c6fecf8a21;p=thirdparty%2Fkernel%2Fstable.git 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 Link: https://lore.kernel.org/r/YMcnl4zCwGWGDVMG@mwanda Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- diff --git a/drivers/staging/gdm724x/gdm_lte.c b/drivers/staging/gdm724x/gdm_lte.c index 79de678807ccb..1eacf82d1bd0f 100644 --- a/drivers/staging/gdm724x/gdm_lte.c +++ b/drivers/staging/gdm724x/gdm_lte.c @@ -689,6 +689,7 @@ static void gdm_lte_multi_sdu_pkt(struct phy_dev *phy_dev, char *buf, int len) struct multi_sdu *multi_sdu = (struct multi_sdu *)buf; struct sdu *sdu = NULL; u8 *data = (u8 *)multi_sdu->data; + int copied; u16 i = 0; u16 num_packet; u16 hci_len; @@ -702,6 +703,12 @@ static void gdm_lte_multi_sdu_pkt(struct phy_dev *phy_dev, char *buf, int len) 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(phy_dev-> @@ -715,7 +722,8 @@ 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; }