From 7b3c1a8576716d825c73ac1739b2b3f0d7226dcf Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 27 Mar 2013 06:40:50 +0000 Subject: 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 -js: This fixes CVE-2013-1929. 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 Acked-by: Jeff Mahoney Signed-off-by: Jiri Slaby Signed-off-by: Greg Kroah-Hartman --- drivers/net/tg3.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c index eaa24fa8c19..173687575c2 100644 --- a/drivers/net/tg3.c +++ b/drivers/net/tg3.c @@ -13067,8 +13067,11 @@ 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 ", TG3_NVM_VPD_LEN - 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: -- cgit v1.2.3