From edca14c8a50e940e8d3be470d136cafa406dd596 Mon Sep 17 00:00:00 2001 From: Richard Mudgett Date: Mon, 22 Aug 2016 12:31:24 -0500 Subject: res_fax.c: Fix deadlock in fax_gateway_indicate_t38(). fax_gateway_indicate_t38() calls ast_indicate_data() which cannot be called with any channel locks already held. A deadlock can happen if the function is operating on a local channel. * Made fax_gateway_indicate_t38() unlock the channel before calling ast_indicate_data() since fax_gateway_indicate_t38() is always called with the channel locked. * Made fax_gateway_indicate_t38() return void since nothing cared about its return value. ASTERISK-26203 Reported by: Etienne Lessard ASTERISK-24822 Reported by: David Brillert ASTERISK-22732 Reported by: Richard Mudgett Change-Id: I701ff2d26c5fc23e0d5a48a3fd98759a9fd09407 --- res/res_fax.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/res/res_fax.c b/res/res_fax.c index 94c512de3..5bbc896c8 100644 --- a/res/res_fax.c +++ b/res/res_fax.c @@ -3001,12 +3001,15 @@ static struct ast_frame *fax_gateway_detect_v21(struct fax_gateway *gateway, str return f; } -static int fax_gateway_indicate_t38(struct ast_channel *chan, struct ast_channel *active, struct ast_control_t38_parameters *control_params) +/*! \pre chan is locked on entry */ +static void fax_gateway_indicate_t38(struct ast_channel *chan, struct ast_channel *active, struct ast_control_t38_parameters *control_params) { if (active == chan) { - return ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, control_params, sizeof(*control_params)); + ast_channel_unlock(chan); + ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, control_params, sizeof(*control_params)); + ast_channel_lock(chan); } else { - return ast_queue_control_data(chan, AST_CONTROL_T38_PARAMETERS, control_params, sizeof(*control_params)); + ast_queue_control_data(chan, AST_CONTROL_T38_PARAMETERS, control_params, sizeof(*control_params)); } } -- cgit v1.2.3