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| author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2022-02-28 16:17:15 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-03-01 18:26:21 -0800 |
| commit | 0b0e2ff10356e7e2ffd66ecdd6eee69a2f03449b (patch) | |
| tree | 31d5bcd796965afcbc8c3e74fb51a3f56a1cc51f /net | |
| parent | 2e77551c61286bac56ebf337b1ac2dd419952c8d (diff) | |
| download | linux-0b0e2ff10356e7e2ffd66ecdd6eee69a2f03449b.tar.bz2 | |
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/dsa/dsa2.c | 2 |
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) |