| Message ID | 20200331090400.18379-1-michal.lowas-rzechonek@silvair.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Brian Gix |
| Headers | show |
| Series | [BlueZ,v2] mesh: Fix FPE in overcommit logic. | expand |
Brian, On 03/31, Michał Lowas-Rzechonek wrote: > During overcommit, mesh_config_save is called in asynchronous mode to > avoid blocking Send() calls. This means that update of cfg->write_time > is scheduled via l_idle_oneshot, so if the next Send() gets scheduled > first, the code may see elapsed time of zero. > > If this happens, then the overcommit logic was already executed and the > overcommit is pending, so we can just return. Ping?
Applied with style guide fixes On Tue, 2020-03-31 at 11:04 +0200, Michał Lowas-Rzechonek wrote: > During overcommit, mesh_config_save is called in asynchronous mode to > avoid blocking Send() calls. This means that update of cfg->write_time > is scheduled via l_idle_oneshot, so if the next Send() gets scheduled > first, the code may see elapsed time of zero. > > If this happens, then the overcommit logic was already executed and the > overcommit is pending, so we can just return. > --- > Fixed the commit log, sorry. > > mesh/mesh-config-json.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/mesh/mesh-config-json.c b/mesh/mesh-config-json.c > index ad2d4d0f8..21f2cfc37 100644 > --- a/mesh/mesh-config-json.c > +++ b/mesh/mesh-config-json.c > @@ -2014,6 +2014,12 @@ bool mesh_config_write_seq_number(struct mesh_config *cfg, uint32_t seq, > timersub(&now, &cfg->write_time, &elapsed); > elapsed_ms = elapsed.tv_sec * 1000 + elapsed.tv_usec / 1000; > > + /* If time since last write is zero, this means that > + * idle_save_config is already pending, so we don't need to do > + * anything. */ > + if (!elapsed_ms) > + return true; > + > cached = seq + (seq - cfg->write_seq) * > 1000 * MIN_SEQ_CACHE_TIME / elapsed_ms; >
diff --git a/mesh/mesh-config-json.c b/mesh/mesh-config-json.c index ad2d4d0f8..21f2cfc37 100644 --- a/mesh/mesh-config-json.c +++ b/mesh/mesh-config-json.c @@ -2014,6 +2014,12 @@ bool mesh_config_write_seq_number(struct mesh_config *cfg, uint32_t seq, timersub(&now, &cfg->write_time, &elapsed); elapsed_ms = elapsed.tv_sec * 1000 + elapsed.tv_usec / 1000; + /* If time since last write is zero, this means that + * idle_save_config is already pending, so we don't need to do + * anything. */ + if (!elapsed_ms) + return true; + cached = seq + (seq - cfg->write_seq) * 1000 * MIN_SEQ_CACHE_TIME / elapsed_ms;