tree a088f8cb55791e92f3dd682a4cf1ac2897bcc26e
parent bf45b1351797c26f7d9ae2ea915bce4eae3814ce
author James Robinson <jamesr@google.com> 1629753537 +0000
committer releases-try-builder <releases-try-builder@fuchsia-infra.iam.gserviceaccount.com> 1631236272 +0000

[fdio] Avoid interpreting uninitialized items as wait results in ppoll

In ppoll, fdio iterates through a set of FDs and computes a wait_many
handle set. This function had a bug where it would not keep track of the
amount of entries in this set correctly and would interpret
uninitialized stack memory as observed kernel signals in the function's
postable. This could result in incorrect state transitions for fdio
objects that update their state based on observed kernel state, such as
stream sockets.

Based on tamird@'s change in
https://fuchsia-review.googlesource.com/c/fuchsia/+/570502/

Bug: b/194705562

Change-Id: I87e0af28663774e21ba0841ecd67786d245b1f3f
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/569981
Reviewed-by: Devon H. O'Dell <dhobsd@google.com>
Reviewed-by: Tamir Duberstein <tamird@google.com>
Commit-Queue: Auto-Submit <auto-submit@fuchsia-infra.iam.gserviceaccount.com>
Fuchsia-Auto-Submit: James Robinson <jamesr@google.com>