| Message ID | 20220117092733.6627-3-gal@nvidia.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 79074a72d335dbd021a716d8cc65cba3b2f706ab |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Couple of skb memory leak fixes | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Clearly marked for net |
| netdev/fixes_present | success | Fixes tag present in non-next series |
| netdev/subject_prefix | success | Link |
| netdev/cover_letter | success | Series has a cover letter |
| netdev/patch_count | success | Link |
| netdev/header_inline | success | No static functions without inline keyword in header files |
| netdev/build_32bit | success | Errors and warnings before: 6 this patch: 6 |
| netdev/cc_maintainers | success | CCed 4 of 4 maintainers |
| netdev/build_clang | success | Errors and warnings before: 22 this patch: 22 |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Signed-off-by tag matches author and committer |
| netdev/verify_fixes | success | Fixes tag looks correct |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 11 this patch: 11 |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 9 lines checked |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/source_inline | success | Was 0 now: 0 |
On Mon, Jan 17, 2022 at 11:27:33AM +0200, Gal Pressman wrote: > The cited Fixes patch moved to a deferred skb approach where the skbs > are not freed immediately under the socket lock. Add a WARN_ON_ONCE() > to verify the deferred list is empty on socket destroy, and empty it to > prevent potential memory leaks. > > Fixes: f35f821935d8 ("tcp: defer skb freeing after socket lock is released") > Signed-off-by: Gal Pressman <gal@nvidia.com> > --- > net/core/sock.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/core/sock.c b/net/core/sock.c > index f32ec08a0c37..4ff806d71921 100644 > --- a/net/core/sock.c > +++ b/net/core/sock.c > @@ -2049,6 +2049,9 @@ void sk_destruct(struct sock *sk) > { > bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE); > > + WARN_ON_ONCE(!llist_empty(&sk->defer_list)); > + sk_defer_free_flush(sk); > + This leads to a link error if CONFIG_INET is not set: s390x-11.2.0-ld: net/core/sock.o: in function `sk_defer_free_flush': linux/./include/net/tcp.h:1378: undefined reference to `__sk_defer_free_flush' make: *** [Makefile:1155: vmlinux] Error 1
On 23/01/2022 11:50, Heiko Carstens wrote: > On Mon, Jan 17, 2022 at 11:27:33AM +0200, Gal Pressman wrote: >> The cited Fixes patch moved to a deferred skb approach where the skbs >> are not freed immediately under the socket lock. Add a WARN_ON_ONCE() >> to verify the deferred list is empty on socket destroy, and empty it to >> prevent potential memory leaks. >> >> Fixes: f35f821935d8 ("tcp: defer skb freeing after socket lock is released") >> Signed-off-by: Gal Pressman <gal@nvidia.com> >> --- >> net/core/sock.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/net/core/sock.c b/net/core/sock.c >> index f32ec08a0c37..4ff806d71921 100644 >> --- a/net/core/sock.c >> +++ b/net/core/sock.c >> @@ -2049,6 +2049,9 @@ void sk_destruct(struct sock *sk) >> { >> bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE); >> >> + WARN_ON_ONCE(!llist_empty(&sk->defer_list)); >> + sk_defer_free_flush(sk); >> + > This leads to a link error if CONFIG_INET is not set: > > s390x-11.2.0-ld: net/core/sock.o: in function `sk_defer_free_flush': > linux/./include/net/tcp.h:1378: undefined reference to `__sk_defer_free_flush' > make: *** [Makefile:1155: vmlinux] Error 1 Thanks, it is fixed in: https://lore.kernel.org/netdev/20220120123440.9088-1-gal@nvidia.com/
diff --git a/net/core/sock.c b/net/core/sock.c index f32ec08a0c37..4ff806d71921 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2049,6 +2049,9 @@ void sk_destruct(struct sock *sk) { bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE); + WARN_ON_ONCE(!llist_empty(&sk->defer_list)); + sk_defer_free_flush(sk); + if (rcu_access_pointer(sk->sk_reuseport_cb)) { reuseport_detach_sock(sk); use_call_rcu = true;
The cited Fixes patch moved to a deferred skb approach where the skbs are not freed immediately under the socket lock. Add a WARN_ON_ONCE() to verify the deferred list is empty on socket destroy, and empty it to prevent potential memory leaks. Fixes: f35f821935d8 ("tcp: defer skb freeing after socket lock is released") Signed-off-by: Gal Pressman <gal@nvidia.com> --- net/core/sock.c | 3 +++ 1 file changed, 3 insertions(+)