From d6f67b83b81bf49b5c62e77143ed39c020e51830 Mon Sep 17 00:00:00 2001 From: Daniel Xu Date: Sun, 1 Oct 2023 12:38:25 -0600 Subject: [PATCH] qga: Fix memory leak when output stream is unused If capture-output is requested but one of the channels goes unused (eg. we attempt to capture stderr but the command never writes to stderr), we can leak memory. guest_exec_output_watch() is (from what I understand) unconditionally called for both streams if output capture is requested. The first call will always pass the `p->size == p->length` check b/c both values are 0. Then GUEST_EXEC_IO_SIZE bytes will be allocated for the stream. But when we reap the exited process there's a `gei->err.length > 0` check to actually free the buffer. Which does not get run if the command doesn't write to the stream. Fix by making free() unconditional. Reviewed-by: Konstantin Kostiuk Signed-off-by: Daniel Xu Signed-off-by: Konstantin Kostiuk --- qga/commands.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/qga/commands.c b/qga/commands.c index 09c683e263..ce172edd2d 100644 --- a/qga/commands.c +++ b/qga/commands.c @@ -206,15 +206,15 @@ GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **errp) #endif if (gei->out.length > 0) { ges->out_data = g_base64_encode(gei->out.data, gei->out.length); - g_free(gei->out.data); ges->has_out_truncated = gei->out.truncated; } + g_free(gei->out.data); if (gei->err.length > 0) { ges->err_data = g_base64_encode(gei->err.data, gei->err.length); - g_free(gei->err.data); ges->has_err_truncated = gei->err.truncated; } + g_free(gei->err.data); QTAILQ_REMOVE(&guest_exec_state.processes, gei, next); g_free(gei); -- 2.11.0