[Spice-devel] [spice-gtk v3] file-xfer: fix segfault on agent disconnection

[Victor Toso]

We are checking self->priv->error but accessing the argument GError *
which is NULL and leads to a segfault.

Program received signal SIGSEGV, Segmentation fault.
spice_file_transfer_task_completed (self=self at entry=0x7fffd0006f00, error=0x0) at channel-main.c:2963
2963            VDAgentFileXferStatusMessage msg = {
(gdb) bt
 #0  spice_file_transfer_task_completed (self=self at entry=0x7fffd0006f00, error=0x0) at channel-main.c:2963
 #1  in file_xfer_data_flushed_cb (source_object=0x7cc1d0, res=0x953390, user_data=user_data at entry=0x7fffd0006f00) at channel-main.c:1857
 #2  in g_task_return_now (task=0x953390) at gtask.c:1108
 #3  in g_task_return (task=0x953390, type=<optimized out>) at gtask.c:1166
 #4  in flush_foreach_remove (key=<optimized out>, value=<optimized out>, user_data=<optimized out>) at channel-main.c:928
 #5  in g_hash_table_foreach_remove_or_steal (hash_table=0x70cea0, func=func at entry=0x7ffff5616f10 <flush_foreach_remove>, user_data=user_data at entry=0x0, notify=notify at entry=1) at ghash.c:1492
 #6  in g_hash_table_foreach_remove (hash_table=<optimized out>, func=func at entry=0x7ffff5616f10 <flush_foreach_remove>, user_data=user_data at entry=0x0) at ghash.c:1538
 #7  in file_xfer_flushed (success=0, channel=0x7cc1d0) at channel-main.c:936
 #8  spice_main_channel_reset_agent (channel=0x7cc1d0) at channel-main.c:466
 #9  set_agent_connected (channel=0x7cc1d0, connected=connected at entry=0) at channel-main.c:1572
 #10 in spice_main_channel_reset (channel=0x7cc1d0, migrating=0) at channel-main.c:485
 #11 in spice_channel_coroutine (data=0x7cc1d0) at spice-channel.c:2564
 #12 in coroutine_trampoline (cc=0x7cb860) at coroutine_ucontext.c:63
 #13 in continuation_trampoline (i0=<optimized out>, i1=<optimized out>) at continuation.c:55
 #14 in ?? () from /lib64/libc.so.6
 #15 in ?? ()
 #16 in ?? ()
Backtrace stopped: Cannot access memory at address
---
 src/channel-main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/channel-main.c b/src/channel-main.c
index 2905d7b..dec5d73 100644
--- a/src/channel-main.c
+++ b/src/channel-main.c
@@ -2964,7 +2964,7 @@ static void spice_file_transfer_task_completed(SpiceFileTransferTask *self,
     if (self->priv->error) {
         VDAgentFileXferStatusMessage msg = {
             .id = self->priv->id,
-            .result = error->code == G_IO_ERROR_CANCELLED ?
+            .result = self->priv->error->code == G_IO_ERROR_CANCELLED ?
                     VD_AGENT_FILE_XFER_STATUS_CANCELLED : VD_AGENT_FILE_XFER_STATUS_ERROR,
         };
         agent_msg_queue_many(self->priv->channel, VD_AGENT_FILE_XFER_STATUS,
@@ -2986,7 +2986,7 @@ static void spice_file_transfer_task_completed(SpiceFileTransferTask *self,
                                self);
     self->priv->pending = TRUE;
 signal:
-    g_signal_emit(self, task_signals[SIGNAL_FINISHED], 0, error);
+    g_signal_emit(self, task_signals[SIGNAL_FINISHED], 0, self->priv->error);
 }
 
 
-- 
2.5.5