From 2899d58462ba868287d6ff3acad3675e7adf934f Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 10 Jul 2024 10:40:42 -0700 Subject: [PATCH 1/2] ethtool: fail closed if we can't get max channel used in indirection tables Commit 0d1b7d6c9274 ("bnxt: fix crashes when reducing ring count with active RSS contexts") proves that allowing indirection table to contain channels with out of bounds IDs may lead to crashes. Currently the max channel check in the core gets skipped if driver can't fetch the indirection table or when we can't allocate memory. Both of those conditions should be extremely rare but if they do happen we should try to be safe and fail the channel change. Reviewed-by: Jacob Keller Link: https://patch.msgid.link/20240710174043.754664-2-kuba@kernel.org Signed-off-by: Jakub Kicinski --- net/ethtool/channels.c | 6 ++---- net/ethtool/common.c | 26 +++++++++++++++----------- net/ethtool/common.h | 2 +- net/ethtool/ioctl.c | 4 +--- 4 files changed, 19 insertions(+), 19 deletions(-) diff --git a/net/ethtool/channels.c b/net/ethtool/channels.c index 7b4bbd674bae..cee188da54f8 100644 --- a/net/ethtool/channels.c +++ b/net/ethtool/channels.c @@ -171,11 +171,9 @@ ethnl_set_channels(struct ethnl_req_info *req_info, struct genl_info *info) */ if (ethtool_get_max_rxnfc_channel(dev, &max_rxnfc_in_use)) max_rxnfc_in_use = 0; - if (!netif_is_rxfh_configured(dev) || - ethtool_get_max_rxfh_channel(dev, &max_rxfh_in_use)) - max_rxfh_in_use = 0; + max_rxfh_in_use = ethtool_get_max_rxfh_channel(dev); if (channels.combined_count + channels.rx_count <= max_rxfh_in_use) { - GENL_SET_ERR_MSG(info, "requested channel counts are too low for existing indirection table settings"); + GENL_SET_ERR_MSG_FMT(info, "requested channel counts are too low for existing indirection table (%d)", max_rxfh_in_use); return -EINVAL; } if (channels.combined_count + channels.rx_count <= max_rxnfc_in_use) { diff --git a/net/ethtool/common.c b/net/ethtool/common.c index 6b2a360dcdf0..8a62375ebd1f 100644 --- a/net/ethtool/common.c +++ b/net/ethtool/common.c @@ -587,35 +587,39 @@ err_free_info: return err; } -int ethtool_get_max_rxfh_channel(struct net_device *dev, u32 *max) +u32 ethtool_get_max_rxfh_channel(struct net_device *dev) { struct ethtool_rxfh_param rxfh = {}; - u32 dev_size, current_max = 0; + u32 dev_size, current_max; int ret; + if (!netif_is_rxfh_configured(dev)) + return 0; + if (!dev->ethtool_ops->get_rxfh_indir_size || !dev->ethtool_ops->get_rxfh) - return -EOPNOTSUPP; + return 0; dev_size = dev->ethtool_ops->get_rxfh_indir_size(dev); if (dev_size == 0) - return -EOPNOTSUPP; + return 0; rxfh.indir = kcalloc(dev_size, sizeof(rxfh.indir[0]), GFP_USER); if (!rxfh.indir) - return -ENOMEM; + return U32_MAX; ret = dev->ethtool_ops->get_rxfh(dev, &rxfh); - if (ret) - goto out; + if (ret) { + current_max = U32_MAX; + goto out_free; + } + current_max = 0; while (dev_size--) current_max = max(current_max, rxfh.indir[dev_size]); - *max = current_max; - -out: +out_free: kfree(rxfh.indir); - return ret; + return current_max; } int ethtool_check_ops(const struct ethtool_ops *ops) diff --git a/net/ethtool/common.h b/net/ethtool/common.h index 28b8aaaf9bcb..b55705a9ad5a 100644 --- a/net/ethtool/common.h +++ b/net/ethtool/common.h @@ -42,7 +42,7 @@ int __ethtool_get_link(struct net_device *dev); bool convert_legacy_settings_to_link_ksettings( struct ethtool_link_ksettings *link_ksettings, const struct ethtool_cmd *legacy_settings); -int ethtool_get_max_rxfh_channel(struct net_device *dev, u32 *max); +u32 ethtool_get_max_rxfh_channel(struct net_device *dev); int ethtool_get_max_rxnfc_channel(struct net_device *dev, u64 *max); int __ethtool_get_ts_info(struct net_device *dev, struct ethtool_ts_info *info); diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c index d72b0fec89af..615812ff8974 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -2049,9 +2049,7 @@ static noinline_for_stack int ethtool_set_channels(struct net_device *dev, * indirection table/rxnfc settings */ if (ethtool_get_max_rxnfc_channel(dev, &max_rxnfc_in_use)) max_rxnfc_in_use = 0; - if (!netif_is_rxfh_configured(dev) || - ethtool_get_max_rxfh_channel(dev, &max_rxfh_in_use)) - max_rxfh_in_use = 0; + max_rxfh_in_use = ethtool_get_max_rxfh_channel(dev); if (channels.combined_count + channels.rx_count <= max_t(u64, max_rxnfc_in_use, max_rxfh_in_use)) return -EINVAL; From 24ac7e5440815bb03bdfa9bc7e43a412b050dbaa Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 10 Jul 2024 10:40:43 -0700 Subject: [PATCH 2/2] ethtool: use the rss context XArray in ring deactivation safety-check ethtool_get_max_rxfh_channel() gets called when user requests deactivating Rx channels. Check the additional RSS contexts, too. While we do track whether RSS context has an indirection table explicitly set by the user, no driver looks at that bit. Assume drivers won't auto-regenerate the additional tables, to be safe. Reviewed-by: Jacob Keller Link: https://patch.msgid.link/20240710174043.754664-3-kuba@kernel.org Signed-off-by: Jakub Kicinski --- net/ethtool/common.c | 33 +++++++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-) diff --git a/net/ethtool/common.c b/net/ethtool/common.c index 8a62375ebd1f..7bda9600efcf 100644 --- a/net/ethtool/common.c +++ b/net/ethtool/common.c @@ -587,21 +587,47 @@ err_free_info: return err; } +static u32 ethtool_get_max_rss_ctx_channel(struct net_device *dev) +{ + struct ethtool_rxfh_context *ctx; + unsigned long context; + u32 max_ring = 0; + + mutex_lock(&dev->ethtool->rss_lock); + xa_for_each(&dev->ethtool->rss_ctx, context, ctx) { + u32 i, *tbl; + + tbl = ethtool_rxfh_context_indir(ctx); + for (i = 0; i < ctx->indir_size; i++) + max_ring = max(max_ring, tbl[i]); + } + mutex_unlock(&dev->ethtool->rss_lock); + + return max_ring; +} + u32 ethtool_get_max_rxfh_channel(struct net_device *dev) { struct ethtool_rxfh_param rxfh = {}; u32 dev_size, current_max; int ret; + /* While we do track whether RSS context has an indirection + * table explicitly set by the user, no driver looks at that bit. + * Assume drivers won't auto-regenerate the additional tables, + * to be safe. + */ + current_max = ethtool_get_max_rss_ctx_channel(dev); + if (!netif_is_rxfh_configured(dev)) - return 0; + return current_max; if (!dev->ethtool_ops->get_rxfh_indir_size || !dev->ethtool_ops->get_rxfh) - return 0; + return current_max; dev_size = dev->ethtool_ops->get_rxfh_indir_size(dev); if (dev_size == 0) - return 0; + return current_max; rxfh.indir = kcalloc(dev_size, sizeof(rxfh.indir[0]), GFP_USER); if (!rxfh.indir) @@ -613,7 +639,6 @@ u32 ethtool_get_max_rxfh_channel(struct net_device *dev) goto out_free; } - current_max = 0; while (dev_size--) current_max = max(current_max, rxfh.indir[dev_size]);