From 80d0f9304484897e4307c9701ddbfaacb925715d Mon Sep 17 00:00:00 2001 From: Nicolas Lacasse Date: Fri, 17 Jan 2020 11:20:29 -0800 Subject: Fix data race in tty.queue.readableSize. We were setting queue.readable without holding the lock. PiperOrigin-RevId: 290306922 --- pkg/sentry/fs/tty/line_discipline.go | 4 +++- pkg/sentry/fs/tty/queue.go | 11 ++--------- 2 files changed, 5 insertions(+), 10 deletions(-) (limited to 'pkg/sentry') diff --git a/pkg/sentry/fs/tty/line_discipline.go b/pkg/sentry/fs/tty/line_discipline.go index 894964260..9fe02657e 100644 --- a/pkg/sentry/fs/tty/line_discipline.go +++ b/pkg/sentry/fs/tty/line_discipline.go @@ -140,8 +140,10 @@ func (l *lineDiscipline) setTermios(ctx context.Context, io usermem.IO, args arc // buffer to its read buffer. Anything already in the read buffer is // now readable. if oldCanonEnabled && !l.termios.LEnabled(linux.ICANON) { - l.inQueue.pushWaitBuf(l) + l.inQueue.mu.Lock() + l.inQueue.pushWaitBufLocked(l) l.inQueue.readable = true + l.inQueue.mu.Unlock() l.slaveWaiter.Notify(waiter.EventIn) } diff --git a/pkg/sentry/fs/tty/queue.go b/pkg/sentry/fs/tty/queue.go index 8b5d4699a..21ccc6f32 100644 --- a/pkg/sentry/fs/tty/queue.go +++ b/pkg/sentry/fs/tty/queue.go @@ -197,16 +197,9 @@ func (q *queue) writeBytes(b []byte, l *lineDiscipline) { q.pushWaitBufLocked(l) } -// pushWaitBuf fills the queue's read buffer with data from the wait buffer. +// pushWaitBufLocked fills the queue's read buffer with data from the wait +// buffer. // -// Preconditions: -// * l.termiosMu must be held for reading. -func (q *queue) pushWaitBuf(l *lineDiscipline) int { - q.mu.Lock() - defer q.mu.Unlock() - return q.pushWaitBufLocked(l) -} - // Preconditions: // * l.termiosMu must be held for reading. // * q.mu must be locked. -- cgit v1.2.3