diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-06-17 16:25:39 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-06-17 16:25:39 -0400 |
| commit | eeb1497277d6b1a0a34ed36b97e18f2bd7d6de0d (patch) | |
| tree | 6bf39e1931999e49ef29b2bdcacc530044dcb1df /net/ipv4/inet_diag.c | |
| parent | 2f9381e98471837b631743270de988e78aad1f96 (diff) | |
| download | lwn-eeb1497277d6b1a0a34ed36b97e18f2bd7d6de0d.tar.gz lwn-eeb1497277d6b1a0a34ed36b97e18f2bd7d6de0d.zip | |
inet_diag: fix inet_diag_bc_audit()
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>
Diffstat (limited to 'net/ipv4/inet_diag.c')
| -rw-r--r-- | net/ipv4/inet_diag.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 6ffe94ca5bc9..3267d3898437 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; } |