From 2a9331ced5251a531bb73994d0596d9ff4b6ea1b Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 26 Mar 2019 01:12:07 -0400 Subject: [PATCH] media: wl128x: prevent two potential buffer overflows [ Upstream commit 9c2ccc324b3a6cbc865ab8b3e1a09e93d3c8ade9 ] Smatch marks skb->data as untrusted so it warns that "evt_hdr->dlen" can copy up to 255 bytes and we only have room for two bytes. Even if this comes from the firmware and we trust it, the new policy generally is just to fix it as kernel hardenning. I can't test this code so I tried to be very conservative. I considered not allowing "evt_hdr->dlen == 1" because it doesn't initialize the whole variable but in the end I decided to allow it and manually initialized "asic_id" and "asic_ver" to zero. Fixes: e8454ff7b9a4 ("[media] drivers:media:radio: wl128x: FM Driver Common sources") Signed-off-by: Dan Carpenter Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/radio/wl128x/fmdrv_common.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/media/radio/wl128x/fmdrv_common.c b/drivers/media/radio/wl128x/fmdrv_common.c index 800d69c..1cf4019 100644 --- a/drivers/media/radio/wl128x/fmdrv_common.c +++ b/drivers/media/radio/wl128x/fmdrv_common.c @@ -489,7 +489,8 @@ int fmc_send_cmd(struct fmdev *fmdev, u8 fm_op, u16 type, void *payload, return -EIO; } /* Send response data to caller */ - if (response != NULL && response_len != NULL && evt_hdr->dlen) { + if (response != NULL && response_len != NULL && evt_hdr->dlen && + evt_hdr->dlen <= payload_len) { /* Skip header info and copy only response data */ skb_pull(skb, sizeof(struct fm_event_msg_hdr)); memcpy(response, skb->data, evt_hdr->dlen); @@ -583,6 +584,8 @@ static void fm_irq_handle_flag_getcmd_resp(struct fmdev *fmdev) return; fm_evt_hdr = (void *)skb->data; + if (fm_evt_hdr->dlen > sizeof(fmdev->irq_info.flag)) + return; /* Skip header info and copy only response data */ skb_pull(skb, sizeof(struct fm_event_msg_hdr)); @@ -1308,7 +1311,7 @@ static int load_default_rx_configuration(struct fmdev *fmdev) static int fm_power_up(struct fmdev *fmdev, u8 mode) { u16 payload; - __be16 asic_id, asic_ver; + __be16 asic_id = 0, asic_ver = 0; int resp_len, ret; u8 fw_name[50]; -- 2.7.4