On Fri, Jul 09, 2021 at 15:43:06 +0200, Tim Wiederhake wrote:
`virThreadPoolNewFull` may call `virThreadPoolExpand` with `prioWorkers` = 0.
Could you elaborate in which situations this happens?
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:
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@redhat.com> --- src/util/virthreadpool.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/src/util/virthreadpool.c b/src/util/virthreadpool.c index 9ddd86a679..c9d2a17ff4 100644 --- a/src/util/virthreadpool.c +++ b/src/util/virthreadpool.c @@ -179,6 +179,9 @@ virThreadPoolExpand(virThreadPool *pool, size_t gain, bool priority) size_t i = 0; struct virThreadPoolWorkerData *data = NULL;
+ if (gain == 0) + return 0;
IMO this is fixing a symptom rather than a root cause unless you justify it.
+ VIR_EXPAND_N(*workers, *curWorkers, gain);
for (i = 0; i < gain; i++) { -- 2.31.1