6.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Moshe Shemesh <moshe@xxxxxxxxxx>
[ Upstream commit aba0e909dc20eceb1de985474af459f82e7b0b82 ]
Devlink health dump get callback should take devlink lock as any other
devlink callback. Otherwise, since devlink_mutex was removed, this
callback is not protected from a race of the reporter being destroyed
while handling the callback.
Add devlink lock to the callback and to any call for
devlink_health_do_dump(). This should be safe as non of the drivers dump
callback implementation takes devlink lock.
As devlink lock is added to any callback of dump, the reporter dump_lock
is now redundant and can be removed.
Fixes: d3efc2a6a6d8 ("net: devlink: remove devlink_mutex")
Signed-off-by: Moshe Shemesh <moshe@xxxxxxxxxx>
Reviewed-by: Jiri Pirko <jiri@xxxxxxxxxx>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@xxxxxxxxx>
Link: https://lore.kernel.org/r/1696510216-189379-1-git-send-email-moshe@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/devlink/health.c | 30 ++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)
diff --git a/net/devlink/health.c b/net/devlink/health.c
index 194340a8bb863..8c6a2e5140d4d 100644
--- a/net/devlink/health.c
+++ b/net/devlink/health.c
@@ -58,7 +58,6 @@ struct devlink_health_reporter {
struct devlink *devlink;
struct devlink_port *devlink_port;
struct devlink_fmsg *dump_fmsg;
- struct mutex dump_lock; /* lock parallel read/write from dump buffers */
u64 graceful_period;
bool auto_recover;
bool auto_dump;
@@ -125,7 +124,6 @@ __devlink_health_reporter_create(struct devlink *devlink,
reporter->graceful_period = graceful_period;
reporter->auto_recover = !!ops->recover;
reporter->auto_dump = !!ops->dump;
- mutex_init(&reporter->dump_lock);
return reporter;
}
@@ -226,7 +224,6 @@ EXPORT_SYMBOL_GPL(devlink_health_reporter_create);
static void
devlink_health_reporter_free(struct devlink_health_reporter *reporter)
{
- mutex_destroy(&reporter->dump_lock);
if (reporter->dump_fmsg)
devlink_fmsg_free(reporter->dump_fmsg);
kfree(reporter);
@@ -609,10 +606,10 @@ int devlink_health_report(struct devlink_health_reporter *reporter,
}
if (reporter->auto_dump) {
- mutex_lock(&reporter->dump_lock);
+ devl_lock(devlink);
/* store current dump of current error, for later analysis */
devlink_health_do_dump(reporter, priv_ctx, NULL);
- mutex_unlock(&reporter->dump_lock);
+ devl_unlock(devlink);
}
if (!reporter->auto_recover)
@@ -1246,7 +1243,7 @@ int devlink_nl_cmd_health_reporter_diagnose_doit(struct sk_buff *skb,
}
static struct devlink_health_reporter *
-devlink_health_reporter_get_from_cb(struct netlink_callback *cb)
+devlink_health_reporter_get_from_cb_lock(struct netlink_callback *cb)
{
const struct genl_dumpit_info *info = genl_dumpit_info(cb);
struct devlink_health_reporter *reporter;
@@ -1256,10 +1253,12 @@ devlink_health_reporter_get_from_cb(struct netlink_callback *cb)
devlink = devlink_get_from_attrs_lock(sock_net(cb->skb->sk), attrs);
if (IS_ERR(devlink))
return NULL;
- devl_unlock(devlink);
reporter = devlink_health_reporter_get_from_attrs(devlink, attrs);
- devlink_put(devlink);
+ if (!reporter) {
+ devl_unlock(devlink);
+ devlink_put(devlink);
+ }
return reporter;
}
@@ -1268,16 +1267,20 @@ int devlink_nl_cmd_health_reporter_dump_get_dumpit(struct sk_buff *skb,
{
struct devlink_nl_dump_state *state = devlink_dump_state(cb);
struct devlink_health_reporter *reporter;
+ struct devlink *devlink;
int err;
- reporter = devlink_health_reporter_get_from_cb(cb);
+ reporter = devlink_health_reporter_get_from_cb_lock(cb);
if (!reporter)
return -EINVAL;
- if (!reporter->ops->dump)
+ devlink = reporter->devlink;
+ if (!reporter->ops->dump) {
+ devl_unlock(devlink);
+ devlink_put(devlink);
return -EOPNOTSUPP;
+ }
- mutex_lock(&reporter->dump_lock);
if (!state->idx) {
err = devlink_health_do_dump(reporter, NULL, cb->extack);
if (err)
@@ -1293,7 +1296,8 @@ int devlink_nl_cmd_health_reporter_dump_get_dumpit(struct sk_buff *skb,
err = devlink_fmsg_dumpit(reporter->dump_fmsg, skb, cb,
DEVLINK_CMD_HEALTH_REPORTER_DUMP_GET);
unlock:
- mutex_unlock(&reporter->dump_lock);
+ devl_unlock(devlink);
+ devlink_put(devlink);
return err;
}
@@ -1310,9 +1314,7 @@ int devlink_nl_cmd_health_reporter_dump_clear_doit(struct sk_buff *skb,
if (!reporter->ops->dump)
return -EOPNOTSUPP;
- mutex_lock(&reporter->dump_lock);
devlink_health_dump_clear(reporter);
- mutex_unlock(&reporter->dump_lock);
return 0;
}
--
2.40.1
