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| author | Nikita Yushchenko <nikita.yoush@cogentembedded.com> | 2016-11-28 07:48:48 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-11-28 22:15:45 +0100 |
| commit | 7a99cd6e213685b78118382e6a8fed506c82ccb2 (patch) | |
| tree | f08b04e49d5002be5dcee747fe5b91b0eb112ef7 /net/dsa | |
| parent | net: handle no dst on skb in icmp6_send (diff) | |
| download | linux-7a99cd6e213685b78118382e6a8fed506c82ccb2.tar.xz linux-7a99cd6e213685b78118382e6a8fed506c82ccb2.zip | |
net: dsa: fix unbalanced dsa_switch_tree reference counting
_dsa_register_switch() gets a dsa_switch_tree object either via
dsa_get_dst() or via dsa_add_dst(). Former path does not increase kref
in returned object (resulting into caller not owning a reference),
while later path does create a new object (resulting into caller owning
a reference).
The rest of _dsa_register_switch() assumes that it owns a reference, and
calls dsa_put_dst().
This causes a memory breakage if first switch in the tree initialized
successfully, but second failed to initialize. In particular, freed
dsa_swith_tree object is left referenced by switch that was initialized,
and later access to sysfs attributes of that switch cause OOPS.
To fix, need to add kref_get() call to dsa_get_dst().
Fixes: 83c0afaec7b7 ("net: dsa: Add new binding implementation")
Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dsa')
| -rw-r--r-- | net/dsa/dsa2.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c index f8a7d9aab437..5fff951a0a49 100644 --- a/net/dsa/dsa2.c +++ b/net/dsa/dsa2.c @@ -28,8 +28,10 @@ static struct dsa_switch_tree *dsa_get_dst(u32 tree) struct dsa_switch_tree *dst; list_for_each_entry(dst, &dsa_switch_trees, list) - if (dst->tree == tree) + if (dst->tree == tree) { + kref_get(&dst->refcount); return dst; + } return NULL; } |