diff options
Diffstat (limited to 'target/linux/generic/backport-5.4/080-wireguard-0115-wireguard-peerlookup-take-lock-before-checking-hash-.patch')
| -rw-r--r-- | target/linux/generic/backport-5.4/080-wireguard-0115-wireguard-peerlookup-take-lock-before-checking-hash-.patch | 62 |
1 files changed, 0 insertions, 62 deletions
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0115-wireguard-peerlookup-take-lock-before-checking-hash-.patch b/target/linux/generic/backport-5.4/080-wireguard-0115-wireguard-peerlookup-take-lock-before-checking-hash-.patch deleted file mode 100644 index e7f46ddf9c..0000000000 --- a/target/linux/generic/backport-5.4/080-wireguard-0115-wireguard-peerlookup-take-lock-before-checking-hash-.patch +++ /dev/null @@ -1,62 +0,0 @@ -From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 -From: "Jason A. Donenfeld" <Jason@zx2c4.com> -Date: Wed, 9 Sep 2020 13:58:15 +0200 -Subject: [PATCH] wireguard: peerlookup: take lock before checking hash in - replace operation - -commit 6147f7b1e90ff09bd52afc8b9206a7fcd133daf7 upstream. - -Eric's suggested fix for the previous commit's mentioned race condition -was to simply take the table->lock in wg_index_hashtable_replace(). The -table->lock of the hash table is supposed to protect the bucket heads, -not the entires, but actually, since all the mutator functions are -already taking it, it makes sense to take it too for the test to -hlist_unhashed, as a defense in depth measure, so that it no longer -races with deletions, regardless of what other locks are protecting -individual entries. This is sensible from a performance perspective -because, as Eric pointed out, the case of being unhashed is already the -unlikely case, so this won't add common contention. And comparing -instructions, this basically doesn't make much of a difference other -than pushing and popping %r13, used by the new `bool ret`. More -generally, I like the idea of locking consistency across table mutator -functions, and this might let me rest slightly easier at night. - -Suggested-by: Eric Dumazet <edumazet@google.com> -Link: https://lore.kernel.org/wireguard/20200908145911.4090480-1-edumazet@google.com/ -Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") -Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> -Signed-off-by: David S. Miller <davem@davemloft.net> -Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> ---- - drivers/net/wireguard/peerlookup.c | 11 ++++++++--- - 1 file changed, 8 insertions(+), 3 deletions(-) - ---- a/drivers/net/wireguard/peerlookup.c -+++ b/drivers/net/wireguard/peerlookup.c -@@ -167,9 +167,13 @@ bool wg_index_hashtable_replace(struct i - struct index_hashtable_entry *old, - struct index_hashtable_entry *new) - { -- if (unlikely(hlist_unhashed(&old->index_hash))) -- return false; -+ bool ret; -+ - spin_lock_bh(&table->lock); -+ ret = !hlist_unhashed(&old->index_hash); -+ if (unlikely(!ret)) -+ goto out; -+ - new->index = old->index; - hlist_replace_rcu(&old->index_hash, &new->index_hash); - -@@ -180,8 +184,9 @@ bool wg_index_hashtable_replace(struct i - * simply gets dropped, which isn't terrible. - */ - INIT_HLIST_NODE(&old->index_hash); -+out: - spin_unlock_bh(&table->lock); -- return true; -+ return ret; - } - - void wg_index_hashtable_remove(struct index_hashtable *table, |