Hello Anatoly, On Fri, 26 Jun 2026 at 12:34, Anatoly Burakov <[email protected]> wrote: > > Coverity has reported (issue ID 501503) a memory leak, but there > actually were a few more problems with IPC than that. This patchset > addresses said problems. > > 1. Using pointer as async request identity is unsafe > > Because asynchronous requests can fail at arbitrary points while > having arbitrary number of requests or alarms already in flight, > using pointer as request identity can create use-after-free risks. > Patchset replaces this with using numeric request ID instead. > > 2. Alarm cancel can deadlock > > Async request handler may attempt to cancel the alarm, but an alarm > might have already been in progress blocking on the same lock that > is held by async request, leading to a deadlock. Patchset removes > the alarm cancel call, and allows the alarm to fire. This is fine, > because due to fix #1 the worst that can happen from calling stale > alarm is a noop, as request ID would not be found. > > 3. Memory leaks > > There are a couple of memory leaks in failure paths. Patchset fixes > those. > > 4. Zero-peer async request does not trigger alarm > > When async requests are performed but no peers exist, we created > a dummy request and put it on the queue, but we never set the > dummy alarm that is supposed to handle that request. Patchset adds > the alarm set in dummy paths where none was present before. > > v7: > - Moved request ID reservation till after allocation > - Added build check for request ID size matching pointer size > - Moved comment about minimum delay alarm from patch 4 to patch 6 > > Note: AI review had a bunch of false positive "errors", all of them > looked at and verified as such. > > v6: > > Moved pieces around, namely: > > 1) apply request ID refactor first as a standalone patch > 2) fix the deadlock immediately after > 3) fix memory leaks next > 4) add missing callback as a final step > > Contents of the patchset remain the same. > > Anatoly Burakov (6): > eal: fix wrong log message in async IPC request > eal: use request ID instead of pointers > eal: avoid deadlock in async IPC alarm callback > eal: fix async IPC memory leaks on partial failure > eal: fix memory leak in async IPC secondary path > eal: fix async IPC callback not fired when no peers > > lib/eal/common/eal_common_proc.c | 137 +++++++++++++++++++++++-------- > 1 file changed, 103 insertions(+), 34 deletions(-)
Series applied with my suggestion on patch 4, thanks for the fixes. -- David Marchand
