[PATCH stable-3.0 2/4] tg3: fix length overflow in VPD firmware parsing

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Kees Cook <keescook@xxxxxxxxxxxx>

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 <keescook@xxxxxxxxxxxx>
Reported-by: Oded Horovitz <oded@xxxxxxxxxxxxxxx>
Reported-by: Brad Spengler <spender@xxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Cc: Matt Carlson <mcarlson@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Acked-by: Jeff Mahoney <jeffm@xxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 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 eaa24fa8..1736875 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:
-- 
1.8.4


--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]