From ed787682255cdecbb3ba8cefc87c20182b97ce7b Mon Sep 17 00:00:00 2001 From: Daniel Anselmi Date: Fri, 21 May 2021 14:30:17 +0200 Subject: [PATCH] scpi_vxi: fix memory leak for SCPI response data in VXI support code Routine scpi_vxi_read_data() invokes device_read_1(), which provides a static buffer where dynamically allocated memory for SCPI response data is kept. Release this memory after getting a copy of the response data, before the next device_read_1() call loses the reference. Valgrind stats without the fix: ==238825== LEAK SUMMARY: ==238825== definitely lost: 45,547,737 bytes in 18,331 blocks ==238825== indirectly lost: 0 bytes in 0 blocks ==238825== possibly lost: 48,154 bytes in 14 blocks ==238825== still reachable: 42,859 bytes in 288 blocks ==238825== suppressed: 0 bytes in 0 blocks Valgrind stats with the fix: ==239413== LEAK SUMMARY: ==239413== definitely lost: 40 bytes in 2 blocks ==239413== indirectly lost: 0 bytes in 0 blocks ==239413== possibly lost: 0 bytes in 0 blocks ==239413== still reachable: 38,613 bytes in 287 blocks ==239413== suppressed: 0 bytes in 0 blocks Remaining leaks in scpi_vxi_open() are of lesser severity because they don't accumulate during execution. [ gsi: rebase to recent master, reword commit message ] --- src/scpi/scpi_vxi.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/src/scpi/scpi_vxi.c b/src/scpi/scpi_vxi.c index 2b8e50de..9b38efda 100644 --- a/src/scpi/scpi_vxi.c +++ b/src/scpi/scpi_vxi.c @@ -195,10 +195,16 @@ static int scpi_vxi_read_data(void *priv, char *buf, int maxlen) if (!read_resp || read_resp->error) { sr_err("Device read failed for %s with error %ld", vxi->address, read_resp ? read_resp->error : 0); + if (read_resp) { + g_free(read_resp->data.data_val); + read_resp->data.data_val = NULL; + } return SR_ERR; } memcpy(buf, read_resp->data.data_val, read_resp->data.data_len); + g_free(read_resp->data.data_val); + read_resp->data.data_val = NULL; vxi->read_complete = read_resp->reason & (RRR_TERM | RRR_END); return read_resp->data.data_len; /* actual number of bytes received */ } -- 2.30.2