On libvirtd startup, the list of priority worker threads is uninitialized
(`pool->prioWorkers` is NULL), and then "expanded" to zero (`prioWorkers`)
entries.
This causes `virThreadPoolExpand` to call `VIR_EXPAND_N` on a null pointer
and an increment of zero. The zero increment triggers `virReallocN` to not
actually allocate any memory and leave the pointer NULL, which, eventually,
causes `memset(NULL, 0, 0)` to be called in `virExpandN`.
`memset` is declared `__attribute__ ((__nonnull__ 1))`, which triggers the
following warning when libvirt is compiled with address sanitizing enabled:
$ meson -Dbuildtype=debug -Db_lundef=false -Db_sanitize=address,undefined
build && ninja -C build
$ ./build/run build/src/libvirtd
src/util/viralloc.c:82:5: runtime error: null pointer passed as
argument 1, which is declared to never be null
Signed-off-by: Tim Wiederhake <twiederh@xxxxxxxxxx>
---
src/util/virthreadpool.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/src/util/virthreadpool.c b/src/util/virthreadpool.c
index 9ddd86a679..92b7cac286 100644
--- a/src/util/virthreadpool.c
+++ b/src/util/virthreadpool.c
@@ -247,10 +247,10 @@ virThreadPoolNewFull(size_t minWorkers,
pool->maxWorkers = maxWorkers;
pool->maxPrioWorkers = prioWorkers;
- if (virThreadPoolExpand(pool, minWorkers, false) < 0)
+ if ((minWorkers > 0) && virThreadPoolExpand(pool, minWorkers, false) < 0)
goto error;
- if (virThreadPoolExpand(pool, prioWorkers, true) < 0)
+ if ((prioWorkers > 0) && virThreadPoolExpand(pool, prioWorkers, true) < 0)
goto error;
return pool;
--
2.31.1
