This is a note to let you know that I've just added the patch titled
inet_diag: validate byte code to prevent oops in inet_diag_bc_run()
to the 3.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
inet_diag-validate-byte-code-to-prevent-oops-in-inet_diag_bc_run.patch
and it can be found in the queue-3.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From eb1545daf210041bf3bc8ec683a43a11f1361fe6 Mon Sep 17 00:00:00 2001
From: Neal Cardwell <[email protected]>
Date: Sat, 8 Dec 2012 19:43:22 +0000
Subject: inet_diag: validate byte code to prevent oops in inet_diag_bc_run()
From: Neal Cardwell <[email protected]>
[ Upstream commit 405c005949e47b6e91359159c24753519ded0c67 ]
Add logic to validate INET_DIAG_BC_S_COND and INET_DIAG_BC_D_COND
operations.
Previously we did not validate the inet_diag_hostcond, address family,
address length, and prefix length. So a malicious user could make the
kernel read beyond the end of the bytecode array by claiming to have a
whole inet_diag_hostcond when the bytecode was not long enough to
contain a whole inet_diag_hostcond of the given address family. Or
they could make the kernel read up to about 27 bytes beyond the end of
a connection address by passing a prefix length that exceeded the
length of addresses of the given family.
Signed-off-by: Neal Cardwell <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
net/ipv4/inet_diag.c | 48 +++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 45 insertions(+), 3 deletions(-)
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -508,6 +508,44 @@ static int valid_cc(const void *bc, int
return 0;
}
+/* Validate an inet_diag_hostcond. */
+static bool valid_hostcond(const struct inet_diag_bc_op *op, int len,
+ int *min_len)
+{
+ int addr_len;
+ struct inet_diag_hostcond *cond;
+
+ /* Check hostcond space. */
+ *min_len += sizeof(struct inet_diag_hostcond);
+ if (len < *min_len)
+ return false;
+ cond = (struct inet_diag_hostcond *)(op + 1);
+
+ /* Check address family and address length. */
+ switch (cond->family) {
+ case AF_UNSPEC:
+ addr_len = 0;
+ break;
+ case AF_INET:
+ addr_len = sizeof(struct in_addr);
+ break;
+ case AF_INET6:
+ addr_len = sizeof(struct in6_addr);
+ break;
+ default:
+ return false;
+ }
+ *min_len += addr_len;
+ if (len < *min_len)
+ return false;
+
+ /* Check prefix length (in bits) vs address length (in bytes). */
+ if (cond->prefix_len > 8 * addr_len)
+ return false;
+
+ return true;
+}
+
static int inet_diag_bc_audit(const void *bytecode, int bytecode_len)
{
const void *bc = bytecode;
@@ -515,18 +553,22 @@ static int inet_diag_bc_audit(const void
while (len > 0) {
const struct inet_diag_bc_op *op = bc;
+ int min_len = sizeof(struct inet_diag_bc_op);
//printk("BC: %d %d %d {%d} / %d\n", op->code, op->yes, op->no, op[1].no, len);
switch (op->code) {
- case INET_DIAG_BC_AUTO:
case INET_DIAG_BC_S_COND:
case INET_DIAG_BC_D_COND:
+ if (!valid_hostcond(bc, len, &min_len))
+ return -EINVAL;
+ /* fall through */
+ case INET_DIAG_BC_AUTO:
case INET_DIAG_BC_S_GE:
case INET_DIAG_BC_S_LE:
case INET_DIAG_BC_D_GE:
case INET_DIAG_BC_D_LE:
case INET_DIAG_BC_JMP:
- if (op->no < 4 || op->no > len + 4 || op->no & 3)
+ if (op->no < min_len || op->no > len + 4 || op->no & 3)
return -EINVAL;
if (op->no < len &&
!valid_cc(bytecode, bytecode_len, len - op->no))
@@ -537,7 +579,7 @@ static int inet_diag_bc_audit(const void
default:
return -EINVAL;
}
- if (op->yes < 4 || op->yes > len + 4 || op->yes & 3)
+ if (op->yes < min_len || op->yes > len + 4 || op->yes & 3)
return -EINVAL;
bc += op->yes;
len -= op->yes;
Patches currently in stable-queue which might be from [email protected] are
queue-3.6/inet_diag-validate-byte-code-to-prevent-oops-in-inet_diag_bc_run.patch
queue-3.6/ipv4-avoid-passing-null-to-inet_putpeer-in-icmpv4_xrlim_allow.patch
queue-3.6/inet_diag-validate-port-comparison-byte-code-to-prevent-unsafe-reads.patch
queue-3.6/inet_diag-avoid-unsafe-and-nonsensical-prefix-matches-in-inet_diag_bc_run.patch
queue-3.6/inet_diag-fix-oops-for-ipv4-af_inet6-tcp-syn-recv-state.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
