| Message ID | 20241023191757.56735-1-kuniyu@amazon.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v1,net-next] socket: Print pf->create() when it does not clear sock->sk on failure. | expand |
On Wed, Oct 23, 2024 at 9:18 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 later removed 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> > --- > include/net/net_debug.h | 4 +++- > net/socket.c | 4 +++- > 2 files changed, 6 insertions(+), 2 deletions(-) > > 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..da00db3824e3 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", %ps would be more appropriate, the offset should be zero, no need to display a full 'symbol+0x0/0x<size>'
From: Eric Dumazet <edumazet@google.com> Date: Wed, 23 Oct 2024 21:45:26 +0200 > On Wed, Oct 23, 2024 at 9:18 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 later removed 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> > > --- > > include/net/net_debug.h | 4 +++- > > net/socket.c | 4 +++- > > 2 files changed, 6 insertions(+), 2 deletions(-) > > > > 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..da00db3824e3 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", > > %ps would be more appropriate, the offset should be zero, no need to > display a full 'symbol+0x0/0x<size>' Ah, exactly! Will use %ps in v2. Thanks! --- pw-bot: cr
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..da00db3824e3 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 later removed 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> --- include/net/net_debug.h | 4 +++- net/socket.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-)