ovpn_crypto_kill_key assumes both crypto slots are populated and
dereferences each slot before checking it. That is not guaranteed: a
peer can have only one installed key, and the kill path may be asked to
remove a key that is not present.
Read each slot once while holding the crypto state lock, check for NULL
before looking at key_id, and only replace the slot that actually
matches.
Fixes: 89d3c0e4612a ("ovpn: kill key and notify userspace in case of IV
exhaustion")
Signed-off-by: Ralf Lici <[email protected]>
---
Changes since v4 of this series
https://lore.kernel.org/openvpn-devel/981d2ea51cca45138210aa52c6e5a0e55c0da7a0.1783099626.git.r...@mandelbit.com/
- Add this previously posted standalone fix to the series so the whole
set can be picked in order.
- No changes since v2 of the original single patch
https://lore.kernel.org/openvpn-devel/19318904cf077d067cd4ec628a22bab03ed7dd29.1782993857.git.r...@mandelbit.com/
Changes since v1 of the original single patch
https://lore.kernel.org/openvpn-devel/9fc33e6f9fae10b9e372a3e06934d697edf5b024.1782829171.git.r...@mandelbit.com/
- Remove unnecessary braces around single-statement if/else branches.
drivers/net/ovpn/crypto.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ovpn/crypto.c b/drivers/net/ovpn/crypto.c
index 90580e32052f..8cb7078a1d93 100644
--- a/drivers/net/ovpn/crypto.c
+++ b/drivers/net/ovpn/crypto.c
@@ -58,15 +58,19 @@ void ovpn_crypto_state_release(struct ovpn_crypto_state *cs)
bool ovpn_crypto_kill_key(struct ovpn_crypto_state *cs, u8 key_id)
{
struct ovpn_crypto_key_slot *ks = NULL;
+ struct ovpn_crypto_key_slot *tmp;
spin_lock_bh(&cs->lock);
- if (rcu_access_pointer(cs->slots[0])->key_id == key_id) {
+ tmp = rcu_access_pointer(cs->slots[0]);
+ if (tmp && tmp->key_id == key_id)
ks = rcu_replace_pointer(cs->slots[0], NULL,
lockdep_is_held(&cs->lock));
- } else if (rcu_access_pointer(cs->slots[1])->key_id == key_id) {
+ else
+ tmp = rcu_access_pointer(cs->slots[1]);
+
+ if (!ks && tmp && tmp->key_id == key_id)
ks = rcu_replace_pointer(cs->slots[1], NULL,
lockdep_is_held(&cs->lock));
- }
spin_unlock_bh(&cs->lock);
if (ks)
--
2.55.0
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