lkml.org 
[lkml]   [2014]   [Jun]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/1 v2] media: dib9000: avoid out of bound access
Date
This updated patch also fixes out of bound access to b[].

In dib9000_risc_apb_access_write() an out of bound access to mb[].

The current test to avoid out of bound access to mb[] is insufficient.
For len = 19 non-existent mb[10] will be accessed.

For odd values of len b[] is accessed out of bounds.

For large values of len an of bound access to mb[] may occur in
dib9000_mbx_send_attr.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
drivers/media/dvb-frontends/dib9000.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/media/dvb-frontends/dib9000.c b/drivers/media/dvb-frontends/dib9000.c
index e540cfb..f75dec4 100644
--- a/drivers/media/dvb-frontends/dib9000.c
+++ b/drivers/media/dvb-frontends/dib9000.c
@@ -1040,13 +1040,18 @@ static int dib9000_risc_apb_access_write(struct dib9000_state *state, u32 addres
if (address >= 1024 || !state->platform.risc.fw_is_running)
return -EINVAL;

+ if (len > 18)
+ return -EINVAL;
+
/* dprintk( "APB access thru wr fw %d %x", address, attribute); */

- mb[0] = (unsigned short)address;
- for (i = 0; i < len && i < 20; i += 2)
- mb[1 + (i / 2)] = (b[i] << 8 | b[i + 1]);
+ mb[0] = (u16)address;
+ for (i = 0; i + 1 < len; i += 2)
+ mb[1 + i / 2] = b[i] << 8 | b[i + 1];
+ if (len & 1)
+ mb[1 + len / 2] = b[len - 1] << 8;

- dib9000_mbx_send_attr(state, OUT_MSG_BRIDGE_APB_W, mb, 1 + len / 2, attribute);
+ dib9000_mbx_send_attr(state, OUT_MSG_BRIDGE_APB_W, mb, (3 + len) / 2, attribute);
return dib9000_mbx_get_message_attr(state, IN_MSG_END_BRIDGE_APB_RW, mb, &s, attribute) == 1 ? 0 : -EINVAL;
}

--
2.0.0


\
 
 \ /
  Last update: 2014-06-19 17:41    [W:0.229 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site