2.6.25-stable review patch. If anyone has any objections, please let us know. ------------------ From: Tom Quetchenbach [ Upstream commit: 8d390efd903485923419584275fd0c2aa4c94183 ] tcp_probe has a bounds-checking bug that causes many programs (less, python) to crash reading /proc/net/tcp_probe. When it outputs a log line to the reader, it only checks if that line alone will fit in the reader's buffer, rather than that line and all the previous lines it has already written. tcpprobe_read also returns the wrong value if copy_to_user fails--it just passes on the return value of copy_to_user (number of bytes not copied), which makes a failure look like a success. This patch fixes the buffer overflow and sets the return value to -EFAULT if copy_to_user fails. Patch is against latest net-2.6; tested briefly and seems to fix the crashes in less and python. Signed-off-by: Tom Quetchenbach Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_probe.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- a/net/ipv4/tcp_probe.c +++ b/net/ipv4/tcp_probe.c @@ -190,19 +190,18 @@ static ssize_t tcpprobe_read(struct file width = tcpprobe_sprint(tbuf, sizeof(tbuf)); - if (width < len) + if (cnt + width < len) tcp_probe.tail = (tcp_probe.tail + 1) % bufsize; spin_unlock_bh(&tcp_probe.lock); /* if record greater than space available return partial buffer (so far) */ - if (width >= len) + if (cnt + width >= len) break; - error = copy_to_user(buf + cnt, tbuf, width); - if (error) - break; + if (copy_to_user(buf + cnt, tbuf, width)) + return -EFAULT; cnt += width; } -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/