From 2b79fa8fddde2d070ca28a2d94394c39bfd8d741 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 715230a44310a8cf66fbfb5a46f9a62a9b2de424 upstream. 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: Matt Carlson Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- 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 c86fa50fec32..c6b990367461 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -13433,8 +13433,11 @@ static void __devinit 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: -- 2.39.2