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authorVladimir Oltean <vladimir.oltean@nxp.com>2022-02-28 16:17:15 +0200
committerJakub Kicinski <kuba@kernel.org>2022-03-01 18:26:21 -0800
commit0b0e2ff10356e7e2ffd66ecdd6eee69a2f03449b (patch)
tree31d5bcd796965afcbc8c3e74fb51a3f56a1cc51f
parent2e77551c61286bac56ebf337b1ac2dd419952c8d (diff)
net: dsa: restore error path of dsa_tree_change_tag_proto
When the DSA_NOTIFIER_TAG_PROTO returns an error, the user space process which initiated the protocol change exits the kernel processing while still holding the rtnl_mutex. So any other process attempting to lock the rtnl_mutex would deadlock after such event. The error handling of DSA_NOTIFIER_TAG_PROTO was inadvertently changed by the blamed commit, introducing this regression. We must still call rtnl_unlock(), and we must still call DSA_NOTIFIER_TAG_PROTO for the old protocol. The latter is due to the limiting design of notifier chains for cross-chip operations, which don't have a built-in error recovery mechanism - we should look into using notifier_call_chain_robust for that. Fixes: dc452a471dba ("net: dsa: introduce tagger-owned storage for private and shared data") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/r/20220228141715.146485-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--net/dsa/dsa2.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index dcad3100b164..209496996cdf 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -1261,7 +1261,7 @@ int dsa_tree_change_tag_proto(struct dsa_switch_tree *dst,
info.tag_ops = tag_ops;
err = dsa_tree_notify(dst, DSA_NOTIFIER_TAG_PROTO, &info);
if (err)
- return err;
+ goto out_unlock;
err = dsa_tree_bind_tag_proto(dst, tag_ops);
if (err)