diff options
| author | Qingfang Deng <dqfext@gmail.com> | 2026-03-16 17:28:23 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-03-17 16:18:48 -0700 |
| commit | bb8539e0e60916ef3ed4a92eb2f3cfd8e34061ef (patch) | |
| tree | 69c7271bc3fcb8d7991d241a99a0aee4cd156996 /drivers/net/ppp | |
| parent | e3f741f587a9826a82304bb5da021e0fe783795d (diff) | |
| download | lwn-bb8539e0e60916ef3ed4a92eb2f3cfd8e34061ef.tar.gz lwn-bb8539e0e60916ef3ed4a92eb2f3cfd8e34061ef.zip | |
ppp: require callers of ppp_dev_name() to hold RCU
ppp_dev_name() holds the RCU read lock internally to protect pch->ppp.
However, as it returns netdev->name to the caller, the caller should
also hold either RCU or RTNL lock to prevent the netdev from being
freed.
The only two references of the function is in the L2TP driver, both of
which already hold RCU. So remove the internal RCU lock and document
that callers must hold RCU.
Signed-off-by: Qingfang Deng <dqfext@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260316092824.479149-1-dqfext@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/ppp')
| -rw-r--r-- | drivers/net/ppp/ppp_generic.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index a036ddfe327b..cb29a6968c63 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -2969,6 +2969,7 @@ int ppp_unit_number(struct ppp_channel *chan) /* * Return the PPP device interface name of a channel. + * Caller must hold RCU read lock. */ char *ppp_dev_name(struct ppp_channel *chan) { @@ -2977,11 +2978,9 @@ char *ppp_dev_name(struct ppp_channel *chan) struct ppp *ppp; if (pch) { - rcu_read_lock(); ppp = rcu_dereference(pch->ppp); if (ppp && ppp->dev) name = ppp->dev->name; - rcu_read_unlock(); } return name; } |