From 715230a44310a8cf66fbfb5a46f9a62a9b2de424 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 27 Mar 2013 06:40:50 +0000 Subject: [PATCH] tg3: fix length overflow in VPD firmware parsing Commit 184b89044fb6e2a74611dafa69b1dce0d98612c6 ("tg3: Use VPD fw version when present") introduced VPD parsing that contained a potential length overflow. Limit the hardware's reported firmware string length (max 255 bytes) to stay inside the driver's firmware string length (32 bytes). On overflow, truncate the formatted firmware string instead of potentially overwriting portions of the tg3 struct. http://cansecwest.com/slides/2013/PrivateCore%20CSW%202013.pdf Signed-off-by: Kees Cook Reported-by: Oded Horovitz Reported-by: Brad Spengler Cc: stable@vger.kernel.org Cc: Matt Carlson Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/tg3.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index 67d2663b3974..17a972734ba7 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -14604,8 +14604,11 @@ static void tg3_read_vpd(struct tg3 *tp) if (j + len > block_end) goto partno; - memcpy(tp->fw_ver, &vpd_data[j], len); - strncat(tp->fw_ver, " bc ", vpdlen - len - 1); + if (len >= sizeof(tp->fw_ver)) + len = sizeof(tp->fw_ver) - 1; + memset(tp->fw_ver, 0, sizeof(tp->fw_ver)); + snprintf(tp->fw_ver, sizeof(tp->fw_ver), "%.*s bc ", len, + &vpd_data[j]); } partno: -- 2.20.1