diff options
| author | Jinke Han <jinkehan@didiglobal.com> | 2026-09-08 15:37:42 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2026-09-17 09:48:42 +0200 |
| commit | a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 (patch) | |
| tree | 73fef824f9a846cf935869d0dbc5070ef6e2f741 /net/ethtool/tsinfo.c | |
| download | linux-stable-a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255.tar.gz linux-stable-a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255.zip | |
x86/kprobes: Fix crash when probing CS CALL instructionsgrafted
When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.
The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:
<__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>: mov %r14,%rdi
<__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>: mov %eax,%r12d
<__hrtimer_run_queues+266>: xchg %ax,%ax
<__hrtimer_run_queues+268>: mov %r13,%rdi
Which triggers this crash:
BUG: unable to handle page fault for address: 00000000000f41c9
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: 0002 [#1] SMP NOPTI
CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
RIP: 0010:__hrtimer_run_queues+0x106/0x230
Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.
The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.
During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.
Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.
[ mingo: Refined the changelog ]
Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000
Diffstat (limited to 'net/ethtool/tsinfo.c')
| -rw-r--r-- | net/ethtool/tsinfo.c | 575 |
1 files changed, 575 insertions, 0 deletions
diff --git a/net/ethtool/tsinfo.c b/net/ethtool/tsinfo.c new file mode 100644 index 000000000..c9b680a9c --- /dev/null +++ b/net/ethtool/tsinfo.c @@ -0,0 +1,575 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/net_tstamp.h> +#include <linux/phy.h> +#include <linux/phy_link_topology.h> +#include <linux/ptp_clock_kernel.h> +#include <net/netdev_lock.h> + +#include "../core/dev.h" +#include "bitset.h" +#include "common.h" +#include "netlink.h" +#include "ts.h" + +struct tsinfo_req_info { + struct ethnl_req_info base; + struct hwtstamp_provider_desc hwprov_desc; +}; + +struct tsinfo_reply_data { + struct ethnl_reply_data base; + struct kernel_ethtool_ts_info ts_info; + struct ethtool_ts_stats stats; +}; + +#define TSINFO_REQINFO(__req_base) \ + container_of(__req_base, struct tsinfo_req_info, base) + +#define TSINFO_REPDATA(__reply_base) \ + container_of(__reply_base, struct tsinfo_reply_data, base) + +#define ETHTOOL_TS_STAT_CNT \ + (__ETHTOOL_A_TS_STAT_CNT - (ETHTOOL_A_TS_STAT_UNSPEC + 1)) + +const struct nla_policy ethnl_tsinfo_get_policy[ETHTOOL_A_TSINFO_MAX + 1] = { + [ETHTOOL_A_TSINFO_HEADER] = + NLA_POLICY_NESTED(ethnl_header_policy_stats), + [ETHTOOL_A_TSINFO_HWTSTAMP_PROVIDER] = + NLA_POLICY_NESTED(ethnl_ts_hwtst_prov_policy), +}; + +int ts_parse_hwtst_provider(const struct nlattr *nest, + struct hwtstamp_provider_desc *hwprov_desc, + struct netlink_ext_ack *extack, + bool *mod) +{ + struct nlattr *tb[ARRAY_SIZE(ethnl_ts_hwtst_prov_policy)]; + int ret; + + ret = nla_parse_nested(tb, + ARRAY_SIZE(ethnl_ts_hwtst_prov_policy) - 1, + nest, + ethnl_ts_hwtst_prov_policy, extack); + if (ret < 0) + return ret; + + if (NL_REQ_ATTR_CHECK(extack, nest, tb, + ETHTOOL_A_TS_HWTSTAMP_PROVIDER_INDEX) || + NL_REQ_ATTR_CHECK(extack, nest, tb, + ETHTOOL_A_TS_HWTSTAMP_PROVIDER_QUALIFIER)) + return -EINVAL; + + ethnl_update_u32(&hwprov_desc->index, + tb[ETHTOOL_A_TS_HWTSTAMP_PROVIDER_INDEX], + mod); + ethnl_update_u32(&hwprov_desc->qualifier, + tb[ETHTOOL_A_TS_HWTSTAMP_PROVIDER_QUALIFIER], + mod); + + return 0; +} + +static int +tsinfo_parse_request(struct ethnl_req_info *req_base, + const struct genl_info *info, + struct nlattr **tb, + struct netlink_ext_ack *extack) +{ + struct tsinfo_req_info *req = TSINFO_REQINFO(req_base); + bool mod = false; + + req->hwprov_desc.index = -1; + + 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); +} + +static int tsinfo_prepare_data(const struct ethnl_req_info *req_base, + struct ethnl_reply_data *reply_base, + const struct genl_info *info) +{ + struct tsinfo_reply_data *data = TSINFO_REPDATA(reply_base); + struct tsinfo_req_info *req = TSINFO_REQINFO(req_base); + struct net_device *dev = reply_base->dev; + int ret; + + ret = ethnl_ops_begin(dev); + if (ret < 0) + return ret; + + if (req->hwprov_desc.index != -1) { + ret = ethtool_get_ts_info_by_phc(dev, &data->ts_info, + &req->hwprov_desc); + ethnl_ops_complete(dev); + return ret; + } + + if (req_base->flags & ETHTOOL_FLAG_STATS) { + ethtool_stats_init((u64 *)&data->stats, + sizeof(data->stats) / sizeof(u64)); + if (dev->ethtool_ops->get_ts_stats) + dev->ethtool_ops->get_ts_stats(dev, &data->stats); + } + + ret = __ethtool_get_ts_info(dev, &data->ts_info); + ethnl_ops_complete(dev); + + return ret; +} + +static int tsinfo_reply_size(const struct ethnl_req_info *req_base, + const struct ethnl_reply_data *reply_base) +{ + const struct tsinfo_reply_data *data = TSINFO_REPDATA(reply_base); + bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS; + const struct kernel_ethtool_ts_info *ts_info = &data->ts_info; + int len = 0; + int ret; + + BUILD_BUG_ON(__SOF_TIMESTAMPING_CNT > 32); + BUILD_BUG_ON(__HWTSTAMP_TX_CNT > 32); + BUILD_BUG_ON(__HWTSTAMP_FILTER_CNT > 32); + + if (ts_info->so_timestamping) { + ret = ethnl_bitset32_size(&ts_info->so_timestamping, NULL, + __SOF_TIMESTAMPING_CNT, + sof_timestamping_names, compact); + if (ret < 0) + return ret; + len += ret; /* _TSINFO_TIMESTAMPING */ + } + if (ts_info->tx_types) { + ret = ethnl_bitset32_size(&ts_info->tx_types, NULL, + __HWTSTAMP_TX_CNT, + ts_tx_type_names, compact); + if (ret < 0) + return ret; + len += ret; /* _TSINFO_TX_TYPES */ + } + if (ts_info->rx_filters) { + ret = ethnl_bitset32_size(&ts_info->rx_filters, NULL, + __HWTSTAMP_FILTER_CNT, + ts_rx_filter_names, compact); + if (ret < 0) + return ret; + len += ret; /* _TSINFO_RX_FILTERS */ + } + if (ts_info->phc_index >= 0) { + len += nla_total_size(sizeof(u32)); /* _TSINFO_PHC_INDEX */ + /* _TSINFO_HWTSTAMP_PROVIDER */ + len += nla_total_size(0) + 2 * nla_total_size(sizeof(u32)); + } + if (ts_info->phc_source) { + len += nla_total_size(sizeof(u32)); /* _TSINFO_HWTSTAMP_SOURCE */ + if (ts_info->phc_phyindex) + /* _TSINFO_HWTSTAMP_PHYINDEX */ + len += nla_total_size(sizeof(u32)); + } + if (req_base->flags & ETHTOOL_FLAG_STATS) + len += nla_total_size(0) + /* _TSINFO_STATS */ + nla_total_size_64bit(sizeof(u64)) * ETHTOOL_TS_STAT_CNT; + + return len; +} + +static int tsinfo_put_stat(struct sk_buff *skb, u64 val, u16 attrtype) +{ + if (val == ETHTOOL_STAT_NOT_SET) + return 0; + if (nla_put_uint(skb, attrtype, val)) + return -EMSGSIZE; + return 0; +} + +static int tsinfo_put_stats(struct sk_buff *skb, + const struct ethtool_ts_stats *stats) +{ + struct nlattr *nest; + + nest = nla_nest_start(skb, ETHTOOL_A_TSINFO_STATS); + if (!nest) + return -EMSGSIZE; + + if (tsinfo_put_stat(skb, stats->tx_stats.pkts, + ETHTOOL_A_TS_STAT_TX_PKTS) || + tsinfo_put_stat(skb, stats->tx_stats.onestep_pkts_unconfirmed, + ETHTOOL_A_TS_STAT_TX_ONESTEP_PKTS_UNCONFIRMED) || + tsinfo_put_stat(skb, stats->tx_stats.lost, + ETHTOOL_A_TS_STAT_TX_LOST) || + tsinfo_put_stat(skb, stats->tx_stats.err, + ETHTOOL_A_TS_STAT_TX_ERR)) + goto err_cancel; + + nla_nest_end(skb, nest); + return 0; + +err_cancel: + nla_nest_cancel(skb, nest); + return -EMSGSIZE; +} + +static int tsinfo_fill_reply(struct sk_buff *skb, + const struct ethnl_req_info *req_base, + const struct ethnl_reply_data *reply_base) +{ + const struct tsinfo_reply_data *data = TSINFO_REPDATA(reply_base); + bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS; + const struct kernel_ethtool_ts_info *ts_info = &data->ts_info; + int ret; + + if (ts_info->so_timestamping) { + ret = ethnl_put_bitset32(skb, ETHTOOL_A_TSINFO_TIMESTAMPING, + &ts_info->so_timestamping, NULL, + __SOF_TIMESTAMPING_CNT, + sof_timestamping_names, compact); + if (ret < 0) + return ret; + } + if (ts_info->tx_types) { + ret = ethnl_put_bitset32(skb, ETHTOOL_A_TSINFO_TX_TYPES, + &ts_info->tx_types, NULL, + __HWTSTAMP_TX_CNT, + ts_tx_type_names, compact); + if (ret < 0) + return ret; + } + if (ts_info->rx_filters) { + ret = ethnl_put_bitset32(skb, ETHTOOL_A_TSINFO_RX_FILTERS, + &ts_info->rx_filters, NULL, + __HWTSTAMP_FILTER_CNT, + ts_rx_filter_names, compact); + if (ret < 0) + return ret; + } + if (ts_info->phc_index >= 0) { + struct nlattr *nest; + + ret = nla_put_u32(skb, ETHTOOL_A_TSINFO_PHC_INDEX, + ts_info->phc_index); + if (ret) + return -EMSGSIZE; + + nest = nla_nest_start(skb, ETHTOOL_A_TSINFO_HWTSTAMP_PROVIDER); + if (!nest) + return -EMSGSIZE; + + if (nla_put_u32(skb, ETHTOOL_A_TS_HWTSTAMP_PROVIDER_INDEX, + ts_info->phc_index) || + nla_put_u32(skb, + ETHTOOL_A_TS_HWTSTAMP_PROVIDER_QUALIFIER, + ts_info->phc_qualifier)) { + nla_nest_cancel(skb, nest); + return -EMSGSIZE; + } + + nla_nest_end(skb, nest); + } + if (ts_info->phc_source) { + if (nla_put_u32(skb, ETHTOOL_A_TSINFO_HWTSTAMP_SOURCE, + ts_info->phc_source)) + return -EMSGSIZE; + + if (ts_info->phc_phyindex && + nla_put_u32(skb, ETHTOOL_A_TSINFO_HWTSTAMP_PHYINDEX, + ts_info->phc_phyindex)) + return -EMSGSIZE; + } + if (req_base->flags & ETHTOOL_FLAG_STATS && + tsinfo_put_stats(skb, &data->stats)) + return -EMSGSIZE; + + return 0; +} + +struct ethnl_tsinfo_dump_ctx { + struct tsinfo_req_info *req_info; + struct tsinfo_reply_data *reply_data; + unsigned long pos_ifindex; + bool netdev_dump_done; + unsigned long pos_phyindex; + enum hwtstamp_provider_qualifier pos_phcqualifier; +}; + +static void *ethnl_tsinfo_prepare_dump(struct sk_buff *skb, + struct net_device *dev, + struct tsinfo_reply_data *reply_data, + struct netlink_callback *cb) +{ + struct ethnl_tsinfo_dump_ctx *ctx = (void *)cb->ctx; + void *ehdr = NULL; + + ehdr = ethnl_dump_put(skb, cb, + ETHTOOL_MSG_TSINFO_GET_REPLY); + if (!ehdr) + return ERR_PTR(-EMSGSIZE); + + reply_data = ctx->reply_data; + memset(reply_data, 0, sizeof(*reply_data)); + reply_data->base.dev = dev; + reply_data->ts_info.cmd = ETHTOOL_GET_TS_INFO; + reply_data->ts_info.phc_index = -1; + + return ehdr; +} + +static int ethnl_tsinfo_end_dump(struct sk_buff *skb, + struct net_device *dev, + struct tsinfo_req_info *req_info, + struct tsinfo_reply_data *reply_data, + void *ehdr) +{ + int ret; + + reply_data->ts_info.so_timestamping |= SOF_TIMESTAMPING_RX_SOFTWARE | + SOF_TIMESTAMPING_SOFTWARE; + + ret = ethnl_fill_reply_header(skb, dev, ETHTOOL_A_TSINFO_HEADER); + if (ret < 0) + return ret; + + ret = tsinfo_fill_reply(skb, &req_info->base, &reply_data->base); + if (ret < 0) + return ret; + + reply_data->base.dev = NULL; + genlmsg_end(skb, ehdr); + + return ret; +} + +static int ethnl_tsinfo_dump_one_phydev(struct sk_buff *skb, + struct net_device *dev, + struct phy_device *phydev, + struct netlink_callback *cb) +{ + struct ethnl_tsinfo_dump_ctx *ctx = (void *)cb->ctx; + struct tsinfo_reply_data *reply_data; + struct tsinfo_req_info *req_info; + void *ehdr = NULL; + int ret = 0; + + if (!phy_has_tsinfo(phydev)) + return -EOPNOTSUPP; + + reply_data = ctx->reply_data; + req_info = ctx->req_info; + ehdr = ethnl_tsinfo_prepare_dump(skb, dev, reply_data, cb); + if (IS_ERR(ehdr)) + return PTR_ERR(ehdr); + + ret = phy_ts_info(phydev, &reply_data->ts_info); + if (ret < 0) + goto err; + + if (reply_data->ts_info.phc_index >= 0) { + reply_data->ts_info.phc_source = HWTSTAMP_SOURCE_PHYLIB; + reply_data->ts_info.phc_phyindex = phydev->phyindex; + } + + ret = ethnl_tsinfo_end_dump(skb, dev, req_info, reply_data, ehdr); + if (ret < 0) + goto err; + + return ret; +err: + genlmsg_cancel(skb, ehdr); + return ret; +} + +static int ethnl_tsinfo_dump_one_netdev(struct sk_buff *skb, + struct net_device *dev, + struct netlink_callback *cb) +{ + struct ethnl_tsinfo_dump_ctx *ctx = (void *)cb->ctx; + const struct ethtool_ops *ops = dev->ethtool_ops; + struct tsinfo_reply_data *reply_data; + struct tsinfo_req_info *req_info; + void *ehdr = NULL; + int ret = 0; + + if (!ops->get_ts_info) + return -EOPNOTSUPP; + + reply_data = ctx->reply_data; + req_info = ctx->req_info; + for (; ctx->pos_phcqualifier < HWTSTAMP_PROVIDER_QUALIFIER_CNT; + ctx->pos_phcqualifier++) { + if (!net_support_hwtstamp_qualifier(dev, + ctx->pos_phcqualifier)) + continue; + + ehdr = ethnl_tsinfo_prepare_dump(skb, dev, reply_data, cb); + if (IS_ERR(ehdr)) + return PTR_ERR(ehdr); + + reply_data->ts_info.phc_qualifier = ctx->pos_phcqualifier; + ret = ops->get_ts_info(dev, &reply_data->ts_info); + if (ret < 0) + goto err; + + if (reply_data->ts_info.phc_index >= 0) + reply_data->ts_info.phc_source = HWTSTAMP_SOURCE_NETDEV; + ret = ethnl_tsinfo_end_dump(skb, dev, req_info, reply_data, + ehdr); + if (ret < 0) + goto err; + } + + return ret; + +err: + genlmsg_cancel(skb, ehdr); + return ret; +} + +static int ethnl_tsinfo_dump_one_net_topo(struct sk_buff *skb, + struct net_device *dev, + struct netlink_callback *cb) +{ + struct ethnl_tsinfo_dump_ctx *ctx = (void *)cb->ctx; + struct phy_device_node *pdn; + int ret = 0; + + if (!ctx->netdev_dump_done) { + ret = ethnl_tsinfo_dump_one_netdev(skb, dev, cb); + if (ret < 0 && ret != -EOPNOTSUPP) + return ret; + ctx->netdev_dump_done = true; + } + + if (!dev->link_topo) { + if (phy_has_tsinfo(dev->phydev)) { + ret = ethnl_tsinfo_dump_one_phydev(skb, dev, + dev->phydev, cb); + if (ret < 0 && ret != -EOPNOTSUPP) + return ret; + } + + return 0; + } + + xa_for_each_start(&dev->link_topo->phys, ctx->pos_phyindex, pdn, + ctx->pos_phyindex) { + if (phy_has_tsinfo(pdn->phy)) { + ret = ethnl_tsinfo_dump_one_phydev(skb, dev, + pdn->phy, cb); + if (ret < 0 && ret != -EOPNOTSUPP) + return ret; + } + } + + return ret; +} + +int ethnl_tsinfo_dumpit(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct ethnl_tsinfo_dump_ctx *ctx = (void *)cb->ctx; + struct net *net = sock_net(skb->sk); + int ret = 0; + + if (ctx->req_info->base.dev) { + struct net_device *dev = ctx->req_info->base.dev; + + netdev_lock_ops_compat(dev); + ret = ethnl_tsinfo_dump_one_net_topo(skb, dev, cb); + netdev_unlock_ops_compat(dev); + return ret; + } + + for_each_netdev_lock_ops_compat_scoped(net, dev, ctx->pos_ifindex) { + ret = ethnl_tsinfo_dump_one_net_topo(skb, dev, cb); + if (ret < 0 && ret != -EOPNOTSUPP) + break; + ctx->pos_phyindex = 0; + ctx->netdev_dump_done = false; + ctx->pos_phcqualifier = HWTSTAMP_PROVIDER_QUALIFIER_PRECISE; + } + + return ret; +} + +int ethnl_tsinfo_start(struct netlink_callback *cb) +{ + const struct genl_dumpit_info *info = genl_dumpit_info(cb); + struct ethnl_tsinfo_dump_ctx *ctx = (void *)cb->ctx; + struct nlattr **tb = info->info.attrs; + struct tsinfo_reply_data *reply_data; + struct tsinfo_req_info *req_info; + int ret; + + BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx)); + + req_info = kzalloc_obj(*req_info); + if (!req_info) + return -ENOMEM; + reply_data = kzalloc_obj(*reply_data); + if (!reply_data) { + ret = -ENOMEM; + goto free_req_info; + } + + ret = ethnl_parse_header_dev_get(&req_info->base, + tb[ETHTOOL_A_TSINFO_HEADER], + sock_net(cb->skb->sk), cb->extack, + false); + 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; + ctx->pos_phyindex = 0; + ctx->netdev_dump_done = false; + ctx->pos_phcqualifier = HWTSTAMP_PROVIDER_QUALIFIER_PRECISE; + + return 0; + +err_dev_put: + ethnl_parse_header_dev_put(&req_info->base); +free_reply_data: + kfree(reply_data); +free_req_info: + kfree(req_info); + + return ret; +} + +int ethnl_tsinfo_done(struct netlink_callback *cb) +{ + struct ethnl_tsinfo_dump_ctx *ctx = (void *)cb->ctx; + struct tsinfo_req_info *req_info = ctx->req_info; + + ethnl_parse_header_dev_put(&req_info->base); + kfree(ctx->reply_data); + kfree(ctx->req_info); + + return 0; +} + +const struct ethnl_request_ops ethnl_tsinfo_request_ops = { + .request_cmd = ETHTOOL_MSG_TSINFO_GET, + .reply_cmd = ETHTOOL_MSG_TSINFO_GET_REPLY, + .hdr_attr = ETHTOOL_A_TSINFO_HEADER, + .req_info_size = sizeof(struct tsinfo_req_info), + .reply_data_size = sizeof(struct tsinfo_reply_data), + + .parse_request = tsinfo_parse_request, + .prepare_data = tsinfo_prepare_data, + .reply_size = tsinfo_reply_size, + .fill_reply = tsinfo_fill_reply, +}; |
