1828713 - Intermittent [ FAILED ] GreaseTests/GreasePresenceAbsenceTestAllVersions.ClientGreaseKeyShare/7, where GetParam() = (1, 772, false)

Status: RESOLVED FIXED

(NSS :: Libraries, defect, P3)

Description

[John Schanck [:jschanck]]

Failing job: https://treeherder.mozilla.org/jobs?repo=nss&selectedTaskRun=C8OSLKAYQQO0Zst1a4hK8w.0

Relevant log output:

Version: DTLS 1.3
server: Changing state from INIT to CONNECTING
client: Changing state from INIT to CONNECTING
client: Handshake success
client: Changing state from CONNECTING to CONNECTED
server: Handshake success
server: Changing state from CONNECTING to CONNECTED
Connected with version 772 cipher suite TLS_AES_128_GCM_SHA256
../../gtests/ssl_gtest/tls_grease_unittest.cc:63: Failure
Expected equality of these values:
  expected
    Which is: 1
  countGreaseInBuffer(buffer)
    Which is: 2
client: Warning alert sent: 0
[  FAILED  ] GreaseTests/GreasePresenceAbsenceTestAllVersions.ClientGreaseKeyShare/6, where GetParam() = (1, 772, true) (6 ms)

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:beurdouche, could you have a look please?

For more information, please visit BugBot documentation.

Comment 2

[Benjamin Beurdouche [:beurdouche]]

Anna, can you please check priority and severity ? : ) Thanks !

Comment 3

[Anna Weine]

I observed this. It fails randomly, that really surprises me.

Comment 4

[Dennis Jackson]

Still failing today (example)

Comment 5

[Intermittent Failures Robot]

1 failures were associated with this bug in the last 7 days.

Repository breakdown:

• nss-try: 1

Table

	no_variant
macosx64--/opt-static	1

For more details, see:

https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=1828713&startday=2025-04-28&endday=2025-05-04&tree=all

Comment 6

[John Schanck [:jschanck]]

Attachment: Bug 1828713 - Fix intermittent ClientGreaseKeyShare test failure. r=#nss-reviewers

countGreaseInBuffer scanned the entire raw key_share extension buffer, including
the random key_exchange bytes of real key shares (e.g., 32 bytes for x25519).
Any aligned 2-byte window in that random data matching a GREASE pattern caused a
spurious count of 2 instead of 1. Fix by parsing the extension structurally and
only checking the group ID fields.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/projects/nss/rev/a5c520d5b666
Fix intermittent ClientGreaseKeyShare test failure. r=nss-reviewers,djackson