From 5a508a254bed9a2e36a5fb96c9065532a6bf1e9c Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Sat, 9 Nov 2019 11:29:46 +0100 Subject: devlink: disallow reload operation during device cleanup There is a race between driver code that does setup/cleanup of device and devlink reload operation that in some drivers works with the same code. Use after free could we easily obtained by running: while true; do echo "0000:00:10.0" >/sys/bus/pci/drivers/mlxsw_spectrum2/bind devlink dev reload pci/0000:00:10.0 & echo "0000:00:10.0" >/sys/bus/pci/drivers/mlxsw_spectrum2/unbind done Fix this by enabling reload only after setup of device is complete and disabling it at the beginning of the cleanup process. Reported-by: Ido Schimmel Fixes: 2d8dc5bbf4e7 ("devlink: Add support for reload") Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- net/core/devlink.c | 39 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) (limited to 'net/core/devlink.c') diff --git a/net/core/devlink.c b/net/core/devlink.c index f80151eeaf51..7d64660a72fc 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -2699,7 +2699,7 @@ static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info) struct devlink *devlink = info->user_ptr[0]; int err; - if (!devlink_reload_supported(devlink)) + if (!devlink_reload_supported(devlink) || !devlink->reload_enabled) return -EOPNOTSUPP; err = devlink_resources_validate(devlink, NULL, info); @@ -6196,12 +6196,49 @@ EXPORT_SYMBOL_GPL(devlink_register); void devlink_unregister(struct devlink *devlink) { mutex_lock(&devlink_mutex); + WARN_ON(devlink_reload_supported(devlink) && + devlink->reload_enabled); devlink_notify(devlink, DEVLINK_CMD_DEL); list_del(&devlink->list); mutex_unlock(&devlink_mutex); } EXPORT_SYMBOL_GPL(devlink_unregister); +/** + * devlink_reload_enable - Enable reload of devlink instance + * + * @devlink: devlink + * + * Should be called at end of device initialization + * process when reload operation is supported. + */ +void devlink_reload_enable(struct devlink *devlink) +{ + mutex_lock(&devlink_mutex); + devlink->reload_enabled = true; + mutex_unlock(&devlink_mutex); +} +EXPORT_SYMBOL_GPL(devlink_reload_enable); + +/** + * devlink_reload_disable - Disable reload of devlink instance + * + * @devlink: devlink + * + * Should be called at the beginning of device cleanup + * process when reload operation is supported. + */ +void devlink_reload_disable(struct devlink *devlink) +{ + mutex_lock(&devlink_mutex); + /* Mutex is taken which ensures that no reload operation is in + * progress while setting up forbidded flag. + */ + devlink->reload_enabled = false; + mutex_unlock(&devlink_mutex); +} +EXPORT_SYMBOL_GPL(devlink_reload_disable); + /** * devlink_free - Free devlink instance resources * -- cgit From d279505b723cba058b604ed8cf9cd4c854e2a041 Mon Sep 17 00:00:00 2001 From: Aya Levin Date: Sun, 10 Nov 2019 14:11:56 +0200 Subject: devlink: Add method for time-stamp on reporter's dump When setting the dump's time-stamp, use ktime_get_real in addition to jiffies. This simplifies the user space implementation and bypasses some inconsistent behavior with translating jiffies to current time. The time taken is transformed into nsec, to comply with y2038 issue. Fixes: c8e1da0bf923 ("devlink: Add health report functionality") Signed-off-by: Aya Levin Acked-by: Jiri Pirko Acked-by: Arnd Bergmann Signed-off-by: David S. Miller --- net/core/devlink.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'net/core/devlink.c') diff --git a/net/core/devlink.c b/net/core/devlink.c index 7d64660a72fc..93905dc7c179 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -4618,6 +4618,7 @@ struct devlink_health_reporter { bool auto_recover; u8 health_state; u64 dump_ts; + u64 dump_real_ts; u64 error_count; u64 recovery_count; u64 last_recovery_ts; @@ -4790,6 +4791,7 @@ static int devlink_health_do_dump(struct devlink_health_reporter *reporter, goto dump_err; reporter->dump_ts = jiffies; + reporter->dump_real_ts = ktime_get_real_ns(); return 0; @@ -4952,6 +4954,10 @@ devlink_nl_health_reporter_fill(struct sk_buff *msg, jiffies_to_msecs(reporter->dump_ts), DEVLINK_ATTR_PAD)) goto reporter_nest_cancel; + if (reporter->dump_fmsg && + nla_put_u64_64bit(msg, DEVLINK_ATTR_HEALTH_REPORTER_DUMP_TS_NS, + reporter->dump_real_ts, DEVLINK_ATTR_PAD)) + goto reporter_nest_cancel; nla_nest_end(msg, reporter_attr); genlmsg_end(msg, hdr); -- cgit