| Message ID | 20241024201458.49412-1-kuniyu@amazon.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 4bbd360a5084d8f890f814327e1d9fbb1f0f6fa1 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v2,net-next] socket: Print pf->create() when it does not clear sock->sk on failure. | expand |
On Thu, Oct 24, 2024 at 10:15 PM Kuniyuki Iwashima <kuniyu@amazon.com> wrote: > > I suggested to put DEBUG_NET_WARN_ON_ONCE() in __sock_create() to > catch possible use-after-free. > > But the warning itself was not useful because our interest is in > the callee than the caller. > > Let's define DEBUG_NET_WARN_ONCE() and print the name of pf->create() > and the socket identifier. > > While at it, we enclose DEBUG_NET_WARN_ON_ONCE() in parentheses too > to avoid a checkpatch error. > > Note that %pf or %pF were obsoleted and will be removed later as per > comment in lib/vsprintf.c. > > Link: https://lore.kernel.org/netdev/202410231427.633734b3-lkp@intel.com/ > Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> > --- Reviewed-by: Eric Dumazet <edumazet@google.com>
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Thu, 24 Oct 2024 13:14:58 -0700 you wrote: > I suggested to put DEBUG_NET_WARN_ON_ONCE() in __sock_create() to > catch possible use-after-free. > > But the warning itself was not useful because our interest is in > the callee than the caller. > > Let's define DEBUG_NET_WARN_ONCE() and print the name of pf->create() > and the socket identifier. > > [...] Here is the summary with links: - [v2,net-next] socket: Print pf->create() when it does not clear sock->sk on failure. https://git.kernel.org/netdev/net-next/c/4bbd360a5084 You are awesome, thank you!
diff --git a/include/net/net_debug.h b/include/net/net_debug.h index 1e74684cbbdb..9fecb1496be3 100644 --- a/include/net/net_debug.h +++ b/include/net/net_debug.h @@ -149,9 +149,11 @@ do { \ #if defined(CONFIG_DEBUG_NET) -#define DEBUG_NET_WARN_ON_ONCE(cond) (void)WARN_ON_ONCE(cond) +#define DEBUG_NET_WARN_ON_ONCE(cond) ((void)WARN_ON_ONCE(cond)) +#define DEBUG_NET_WARN_ONCE(cond, format...) ((void)WARN_ONCE(cond, format)) #else #define DEBUG_NET_WARN_ON_ONCE(cond) BUILD_BUG_ON_INVALID(cond) +#define DEBUG_NET_WARN_ONCE(cond, format...) BUILD_BUG_ON_INVALID(cond) #endif #endif /* _LINUX_NET_DEBUG_H */ diff --git a/net/socket.c b/net/socket.c index 9a8e4452b9b2..5fb3d265e492 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1578,7 +1578,9 @@ int __sock_create(struct net *net, int family, int type, int protocol, /* ->create should release the allocated sock->sk object on error * and make sure sock->sk is set to NULL to avoid use-after-free */ - DEBUG_NET_WARN_ON_ONCE(sock->sk); + DEBUG_NET_WARN_ONCE(sock->sk, + "%ps must clear sock->sk on failure, family: %d, type: %d, protocol: %d\n", + pf->create, family, type, protocol); goto out_module_put; }
I suggested to put DEBUG_NET_WARN_ON_ONCE() in __sock_create() to catch possible use-after-free. But the warning itself was not useful because our interest is in the callee than the caller. Let's define DEBUG_NET_WARN_ONCE() and print the name of pf->create() and the socket identifier. While at it, we enclose DEBUG_NET_WARN_ON_ONCE() in parentheses too to avoid a checkpatch error. Note that %pf or %pF were obsoleted and will be removed later as per comment in lib/vsprintf.c. Link: https://lore.kernel.org/netdev/202410231427.633734b3-lkp@intel.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> --- v2: * Use %ps instead of %pS as the offset is always zero v1: https://lore.kernel.org/netdev/20241023191757.56735-1-kuniyu@amazon.com/ --- include/net/net_debug.h | 4 +++- net/socket.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-)