lkml.org 
[lkml]   [2012]   [Mar]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[34-longterm 189/196] inet_diag: fix inet_diag_bc_audit()
Date
From: Eric Dumazet <eric.dumazet@gmail.com>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.
-------------------

commit eeb1497277d6b1a0a34ed36b97e18f2bd7d6de0d upstream.

A malicious user or buggy application can inject code and trigger an
infinite loop in inet_diag_bc_audit()

Also make sure each instruction is aligned on 4 bytes boundary, to avoid
unaligned accesses.

Reported-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
net/ipv4/inet_diag.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 7403b9b..99366cb 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -437,7 +437,7 @@ static int valid_cc(const void *bc, int len, int cc)
return 0;
if (cc == len)
return 1;
- if (op->yes < 4)
+ if (op->yes < 4 || op->yes & 3)
return 0;
len -= op->yes;
bc += op->yes;
@@ -447,11 +447,11 @@ static int valid_cc(const void *bc, int len, int cc)

static int inet_diag_bc_audit(const void *bytecode, int bytecode_len)
{
- const unsigned char *bc = bytecode;
+ const void *bc = bytecode;
int len = bytecode_len;

while (len > 0) {
- struct inet_diag_bc_op *op = (struct inet_diag_bc_op *)bc;
+ const struct inet_diag_bc_op *op = bc;

//printk("BC: %d %d %d {%d} / %d\n", op->code, op->yes, op->no, op[1].no, len);
switch (op->code) {
@@ -462,22 +462,20 @@ static int inet_diag_bc_audit(const void *bytecode, int bytecode_len)
case INET_DIAG_BC_S_LE:
case INET_DIAG_BC_D_GE:
case INET_DIAG_BC_D_LE:
- if (op->yes < 4 || op->yes > len + 4)
- return -EINVAL;
case INET_DIAG_BC_JMP:
- if (op->no < 4 || op->no > len + 4)
+ if (op->no < 4 || op->no > len + 4 || op->no & 3)
return -EINVAL;
if (op->no < len &&
!valid_cc(bytecode, bytecode_len, len - op->no))
return -EINVAL;
break;
case INET_DIAG_BC_NOP:
- if (op->yes < 4 || op->yes > len + 4)
- return -EINVAL;
break;
default:
return -EINVAL;
}
+ if (op->yes < 4 || op->yes > len + 4 || op->yes & 3)
+ return -EINVAL;
bc += op->yes;
len -= op->yes;
}
--
1.7.9.3


\
 
 \ /
  Last update: 2012-03-13 01:31    [W:0.518 / U:0.864 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site