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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2005-10-23 16:37:48 +1000 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2005-10-23 16:37:48 +1000 |
| commit | 6fb9974f49f7a6032118c5b6caa6e08e7097913e (patch) | |
| tree | a1e8f77c1c5cd6a45842f4f02582bb583e6d1019 /net/core | |
| parent | 203755029e063066ecc4cf5eee1110ab946c2d88 (diff) | |
| download | linux-6fb9974f49f7a6032118c5b6caa6e08e7097913e.tar.gz linux-6fb9974f49f7a6032118c5b6caa6e08e7097913e.tar.bz2 linux-6fb9974f49f7a6032118c5b6caa6e08e7097913e.zip | |
[NEIGH] Fix add_timer race in neigh_add_timer
neigh_add_timer cannot use add_timer unconditionally. The reason is that
by the time it has obtained the write lock someone else (e.g., neigh_update)
could have already added a new timer.
So it should only use mod_timer and deal with its return value accordingly.
This bug would have led to rare neighbour cache entry leaks.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/neighbour.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 766caa0dd930..37d8d8c29522 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -816,10 +816,10 @@ static void neigh_timer_handler(unsigned long arg) } if (neigh->nud_state & NUD_IN_TIMER) { - neigh_hold(neigh); if (time_before(next, jiffies + HZ/2)) next = jiffies + HZ/2; - neigh_add_timer(neigh, next); + if (!mod_timer(&neigh->timer, next)) + neigh_hold(neigh); } if (neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) { struct sk_buff *skb = skb_peek(&neigh->arp_queue); |