On 06/01/2018 01:27 PM, Marc-André Lureau wrote:
> A socket chardev may not have associated address (when adding client
> fd manually for example). But on disconnect, updating socket filename
> expects an address and may lead to this crash:
>
> Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
> 0x0000555555d8c70c in SocketAddress_to_str (prefix=0x555556043062
> "disconnected:", addr=0x0, is_listen=false, is_telnet=false) at
> /home/elmarco/src/qq/chardev/char-socket.c:388
> 388 switch (addr->type) {
> (gdb) bt
> #0 0x0000555555d8c70c in SocketAddress_to_str (prefix=0x555556043062
> "disconnected:", addr=0x0, is_listen=false, is_telnet=false) at
> /home/elmarco/src/qq/chardev/char-socket.c:388
> #1 0x0000555555d8c8aa in update_disconnected_filename (s=0x555556b1ed00)
> at /home/elmarco/src/qq/chardev/char-socket.c:419
> #2 0x0000555555d8c959 in tcp_chr_disconnect (chr=0x555556b1ed00) at
> /home/elmarco/src/qq/chardev/char-socket.c:438
> #3 0x0000555555d8cba1 in tcp_chr_hup (channel=0x555556b75690,
> cond=G_IO_HUP, opaque=0x555556b1ed00) at
> /home/elmarco/src/qq/chardev/char-socket.c:482
> #4 0x0000555555da596e in qio_channel_fd_source_dispatch
> (source=0x555556bb68b0, callback=0x555555d8cb58 <tcp_chr_hup>,
> user_data=0x555556b1ed00) at /home/elmarco/src/qq/io/channel-watch.c:84
>
> Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> ---
> chardev/char-socket.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/chardev/char-socket.c b/chardev/char-socket.c
> index 159e69c3b1..f1b7907798 100644
> --- a/chardev/char-socket.c
> +++ b/chardev/char-socket.c
> @@ -416,8 +416,11 @@ static void update_disconnected_filename(SocketChardev
> *s)
> Chardev *chr = CHARDEV(s);
>
> g_free(chr->filename);
> - chr->filename = SocketAddress_to_str("disconnected:", s->addr,
> - s->is_listen, s->is_telnet);
> + chr->filename = NULL;
> + if (s->addr) {
Isn't it more robust to add this check in SocketAddress_to_str()?
static char *SocketAddress_to_str(const char *prefix, SocketAddress
*addr,
bool is_listen, bool is_telnet)
{
if (!addr) {
return NULL;
}
switch (addr->type) {
...
> + chr->filename = SocketAddress_to_str("disconnected:", s->addr,
> + s->is_listen, s->is_telnet);
> + }
> }
>
> /* NB may be called even if tcp_chr_connect has not been
>
