@@ -548,6 +548,17 @@ static bool valid_hostcond(const struct inet_diag_bc_op *op, int len,
return true;
}
+/* Validate a port comparison operator. */
+static inline bool valid_port_comparison(const struct inet_diag_bc_op *op,
+ int len, int *min_len)
+{
+ /* Port comparisons put the port in a follow-on inet_diag_bc_op. */
+ *min_len += sizeof(struct inet_diag_bc_op);
+ if (len < *min_len)
+ return false;
+ return true;
+}
+
static int inet_diag_bc_audit(const void *bytecode, int bytecode_len)
{
const void *bc = bytecode;
@@ -563,24 +574,30 @@ static int inet_diag_bc_audit(const void *bytecode, int bytecode_len)
case INET_DIAG_BC_D_COND:
if (!valid_hostcond(bc, len, &min_len))
return -EINVAL;
- /* fall through */
- case INET_DIAG_BC_AUTO:
+ break;
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 < min_len || op->no > len + 4 || op->no & 3)
- return -EINVAL;
- if (op->no < len &&
- !valid_cc(bytecode, bytecode_len, len - op->no))
+ if (!valid_port_comparison(bc, len, &min_len))
return -EINVAL;
break;
+ case INET_DIAG_BC_AUTO:
+ case INET_DIAG_BC_JMP:
case INET_DIAG_BC_NOP:
break;
default:
return -EINVAL;
}
+
+ if (op->code != INET_DIAG_BC_NOP) {
+ 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))
+ return -EINVAL;
+ }
+
if (op->yes < min_len || op->yes > len + 4 || op->yes & 3)
return -EINVAL;
bc += op->yes;
This is a note to let you know that I have just added a patch titled inet_diag: validate port comparison byte code to prevent to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ From ef5b7a2068d060686870d93b6826d02773cea9d3 Mon Sep 17 00:00:00 2001 From: Neal Cardwell <ncardwell@google.com> Date: Sun, 9 Dec 2012 11:09:54 +0000 Subject: [PATCH] inet_diag: validate port comparison byte code to prevent unsafe reads commit 5e1f54201cb481f40a04bc47e1bc8c093a189e23 upstream. Add logic to verify that a port comparison byte code operation actually has the second inet_diag_bc_op from which we read the port for such operations. Previously the code blindly referenced op[1] without first checking whether a second inet_diag_bc_op struct could fit there. So a malicious user could make the kernel read 4 bytes beyond the end of the bytecode array by claiming to have a whole port comparison byte code (2 inet_diag_bc_op structs) when in fact the bytecode was not long enough to hold both. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- net/ipv4/inet_diag.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) -- 1.7.9.5