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ipsec: Fix deadlock in xfrm_state management.

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Ever since commit 4c563f7669
("[XFRM]: Speed up xfrm_policy and xfrm_state walking") it is
illegal to call __xfrm_state_destroy (and thus xfrm_state_put())
with xfrm_state_lock held.  If we do, we'll deadlock since we
have the lock already and __xfrm_state_destroy() tries to take
it again.

Fix this by pushing the xfrm_state_put() calls after the lock
is dropped.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2008-09-02 20:14:15 -07:00
parent 06770843c2
commit 37b08e34a9
1 changed files with 23 additions and 9 deletions
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32
net/xfrm/xfrm_state.c
View file

@ -780,11 +780,13 @@ xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr,
{
unsigned int h;
struct hlist_node *entry;
struct xfrm_state *x, *x0;
struct xfrm_state *x, *x0, *to_put;
int acquire_in_progress = 0;
int error = 0;
struct xfrm_state *best = NULL;
to_put = NULL;
spin_lock_bh(&xfrm_state_lock);
h = xfrm_dst_hash(daddr, saddr, tmpl->reqid, family);
hlist_for_each_entry(x, entry, xfrm_state_bydst+h, bydst) {
@ -833,7 +835,7 @@ xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr,
if (tmpl->id.spi &&
(x0 = __xfrm_state_lookup(daddr, tmpl->id.spi,
tmpl->id.proto, family)) != NULL) {
xfrm_state_put(x0);
to_put = x0;
error = -EEXIST;
goto out;
}
@ -849,7 +851,7 @@ xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr,
error = security_xfrm_state_alloc_acquire(x, pol->security, fl->secid);
if (error) {
x->km.state = XFRM_STATE_DEAD;
xfrm_state_put(x);
to_put = x;
x = NULL;
goto out;
}
@ -870,7 +872,7 @@ xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr,
xfrm_hash_grow_check(x->bydst.next != NULL);
} else {
x->km.state = XFRM_STATE_DEAD;
xfrm_state_put(x);
to_put = x;
x = NULL;
error = -ESRCH;
}
@ -881,6 +883,8 @@ out:
else
*err = acquire_in_progress ? -EAGAIN : error;
spin_unlock_bh(&xfrm_state_lock);
if (to_put)
xfrm_state_put(to_put);
return x;
}
@ -1067,18 +1071,20 @@ static struct xfrm_state *__xfrm_find_acq_byseq(u32 seq);
int xfrm_state_add(struct xfrm_state *x)
{
struct xfrm_state *x1;
struct xfrm_state *x1, *to_put;
int family;
int err;
int use_spi = xfrm_id_proto_match(x->id.proto, IPSEC_PROTO_ANY);
family = x->props.family;
to_put = NULL;
spin_lock_bh(&xfrm_state_lock);
x1 = __xfrm_state_locate(x, use_spi, family);
if (x1) {
xfrm_state_put(x1);
to_put = x1;
x1 = NULL;
err = -EEXIST;
goto out;
@ -1088,7 +1094,7 @@ int xfrm_state_add(struct xfrm_state *x)
x1 = __xfrm_find_acq_byseq(x->km.seq);
if (x1 && ((x1->id.proto != x->id.proto) ||
xfrm_addr_cmp(&x1->id.daddr, &x->id.daddr, family))) {
xfrm_state_put(x1);
to_put = x1;
x1 = NULL;
}
}
@ -1110,6 +1116,9 @@ out:
xfrm_state_put(x1);
}
if (to_put)
xfrm_state_put(to_put);
return err;
}
EXPORT_SYMBOL(xfrm_state_add);
@ -1269,10 +1278,12 @@ EXPORT_SYMBOL(xfrm_state_migrate);
int xfrm_state_update(struct xfrm_state *x)
{
struct xfrm_state *x1;
struct xfrm_state *x1, *to_put;
int err;
int use_spi = xfrm_id_proto_match(x->id.proto, IPSEC_PROTO_ANY);
to_put = NULL;
spin_lock_bh(&xfrm_state_lock);
x1 = __xfrm_state_locate(x, use_spi, x->props.family);
@ -1281,7 +1292,7 @@ int xfrm_state_update(struct xfrm_state *x)
goto out;
if (xfrm_state_kern(x1)) {
xfrm_state_put(x1);
to_put = x1;
err = -EEXIST;
goto out;
}
@ -1295,6 +1306,9 @@ int xfrm_state_update(struct xfrm_state *x)
out:
spin_unlock_bh(&xfrm_state_lock);
if (to_put)
xfrm_state_put(to_put);
if (err)
return err;