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net.openssl: fix double-free on shutdown() #27482

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net.openssl: fix double-free on shutdown() #27482

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51 changes: 31 additions & 20 deletions vlib/net/openssl/ssl_connection.c.v
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Original file line number Diff line number Diff line change
Expand Up @@ -98,37 +98,48 @@ pub fn (mut s SSLConn) shutdown() ! {
eprintln(@METHOD)
}

if s.ssl != 0 {
if s.ssl != unsafe { nil } {
deadline := ssl_timeout_deadline(s.duration)
for {
mut res := C.SSL_shutdown(voidptr(s.ssl))
mut shutdown_done := false

for !shutdown_done {
res := C.SSL_shutdown(voidptr(s.ssl))
if res == 1 {
shutdown_done = true
break
}

err_res := ssl_error(res, s.ssl) or {
break // We break to free rest of resources
}
if err_res == .ssl_error_want_read {
s.wait_for_read(ssl_remaining_timeout(deadline))!
continue
} else if err_res == .ssl_error_want_write {
s.wait_for_write(ssl_remaining_timeout(deadline))!
if res == 0 {
// Second SSL_shutdown() needed for full bidirectional shutdown.
continue
Comment on lines +111 to 113

@chatgpt-codex-connector chatgpt-codex-connector Bot Jun 18, 2026

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P2 Badge Wait on retryable SSL_shutdown(0) results

When the underlying socket is non-blocking, such as builds using -d net_nonblocking_sockets or callers that set the TCP fd non-blocking, OpenSSL can return 0 from SSL_shutdown() because the shutdown is still in progress and SSL_get_error() would report SSL_ERROR_WANT_READ/SSL_ERROR_WANT_WRITE. This unconditional continue skips the existing wait logic below, so shutdown can busy-spin until the fd happens to become ready or forever if it never does; handle res == 0 through ssl_error() and wait/retry instead of immediately looping.

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}
if s.ssl != 0 {
unsafe { C.SSL_free(voidptr(s.ssl)) }
}
if s.sslctx != 0 {
C.SSL_CTX_free(s.sslctx)

err_res := ssl_error(res, s.ssl) or { break }

match err_res {
.ssl_error_want_read {
s.wait_for_read(ssl_remaining_timeout(deadline)) or { break }
}
.ssl_error_want_write {
s.wait_for_write(ssl_remaining_timeout(deadline)) or { break }
}
else {
break
}
}
return error('net.openssl Could not connect using SSL. (${err_res}),err')
}
C.SSL_free(voidptr(s.ssl))

// Always free SSL object first.
if s.ssl != unsafe { nil } {
unsafe { C.SSL_free(voidptr(s.ssl)) }
s.ssl = unsafe { nil }
}
}
if s.sslctx != 0 {

if s.sslctx != unsafe { nil } {
C.SSL_CTX_free(s.sslctx)
s.sslctx = unsafe { nil }
}

if s.owns_socket {
net.shutdown(s.handle)
net.close(s.handle)!
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