From 1de405699c62c3a9544bcdcfb9eff8a01cfc7582 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 26 May 2026 08:35:29 -0700 Subject: [PATCH] ethtool: tsinfo: fix uninitialized stats on the by-PHC path tsinfo_prepare_data() has two code paths: a "by-PHC" path for user-specified hardware timestamping providers, and the old path. Commit 89e281ebff72 ("ethtool: init tsinfo stats if requested") added ethtool_stats_init() to mark stat slots as ETHTOOL_STAT_NOT_SET before the driver callback populates them, but placed the call inside the old-path block. When commit b9e3f7dc9ed9 ("net: ethtool: tsinfo: Enhance tsinfo to support several hwtstamp by net topology") added the by-PHC early return, it landed above the stats initialization. On that path the stats array retains the zero-fill from ethnl_init_reply_data()'s zalloc. This leads to the reply including a stats nest with four zero-valued attributes that should have been absent. Reject GET requests for stats with HWTSTAMP_PROVIDER or dump. Fixes: b9e3f7dc9ed9 ("net: ethtool: tsinfo: Enhance tsinfo to support several hwtstamp by net topology") Reviewed-by: Maxime Chevallier Link: https://patch.msgid.link/20260526153533.2779187-7-kuba@kernel.org Signed-off-by: Jakub Kicinski --- net/ethtool/tsinfo.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/net/ethtool/tsinfo.c b/net/ethtool/tsinfo.c index a865f0fdd26b..f54fe6b662b2 100644 --- a/net/ethtool/tsinfo.c +++ b/net/ethtool/tsinfo.c @@ -83,6 +83,11 @@ tsinfo_parse_request(struct ethnl_req_info *req_base, if (!tb[ETHTOOL_A_TSINFO_HWTSTAMP_PROVIDER]) return 0; + if (req_base->flags & ETHTOOL_FLAG_STATS) { + NL_SET_ERR_MSG(extack, "can't query statistics for a provider"); + return -EOPNOTSUPP; + } + return ts_parse_hwtst_provider(tb[ETHTOOL_A_TSINFO_HWTSTAMP_PROVIDER], &req->hwprov_desc, extack, &mod); } @@ -523,6 +528,12 @@ int ethnl_tsinfo_start(struct netlink_callback *cb) if (ret < 0) goto free_reply_data; + if (req_info->base.flags & ETHTOOL_FLAG_STATS) { + NL_SET_ERR_MSG(cb->extack, "stats not supported in dump"); + ret = -EOPNOTSUPP; + goto err_dev_put; + } + ctx->req_info = req_info; ctx->reply_data = reply_data; ctx->pos_ifindex = 0; @@ -532,6 +543,8 @@ int ethnl_tsinfo_start(struct netlink_callback *cb) return 0; +err_dev_put: + ethnl_parse_header_dev_put(&req_info->base); free_reply_data: kfree(reply_data); free_req_info: