diff options
| author | Kuniyuki Iwashima <kuniyu@google.com> | 2025-07-16 22:08:17 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-07-17 16:25:21 -0700 |
| commit | dd103c9a53752d3754a3182ec8dd97885680cfe2 (patch) | |
| tree | a7c72c07baf447fdb412409f2673b0425f082aaf /net/ipv6/ndisc.c | |
| parent | neighbour: Use rcu_dereference() in pneigh_get_{first,next}(). (diff) | |
| download | linux-dd103c9a53752d3754a3182ec8dd97885680cfe2.tar.gz linux-dd103c9a53752d3754a3182ec8dd97885680cfe2.zip | |
neighbour: Remove __pneigh_lookup().
__pneigh_lookup() is the lockless version of pneigh_lookup(),
but its only caller pndisc_is_router() holds the table lock and
reads pneigh_netry.flags.
This is because accessing pneigh_entry after pneigh_lookup() was
illegal unless the caller holds RTNL or the table lock.
Now, pneigh_entry is guaranteed to be alive during the RCU critical
section.
Let's call pneigh_lookup() and use READ_ONCE() for n->flags in
pndisc_is_router() and remove __pneigh_lookup().
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250716221221.442239-13-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to '')
| -rw-r--r-- | net/ipv6/ndisc.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index a3ac26c1df6d..7d5abb3158ec 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -768,11 +768,9 @@ static int pndisc_is_router(const void *pkey, struct pneigh_entry *n; int ret = -1; - read_lock_bh(&nd_tbl.lock); - n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); + n = pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); if (n) - ret = !!(n->flags & NTF_ROUTER); - read_unlock_bh(&nd_tbl.lock); + ret = !!(READ_ONCE(n->flags) & NTF_ROUTER); return ret; } |