| Message ID | 155613366350.20131.18131808324848803588.stgit@john-XPS-13-9360 |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | sockmap/ktls fixes | expand |
On Wed, 24 Apr 2019 12:21:03 -0700, John Fastabend wrote: > It is possible (via shutdown()) for TCP socks to go through TCP_CLOSE > state via tcp_disconnect() without calling into close callback. This > would allow a kTLS enabled socket to exist outside of ESTABLISHED > state which is not supported. > > Solve this the same way we solved the sock{map|hash} case by adding > an unhash hook to remove tear down the TLS state. > > In the process we also make the close hook more robust. We add a put > call into the close path, also in the unhash path, to remove the > reference to ulp data after free. Its no longer valid and may confuse > things later if the socket (re)enters kTLS code paths. Second we add > an 'if(ctx)' check to ensure the ctx is still valid and not released > from a previous unhash/close path. > > Fixes: d91c3e17f75f2 ("net/tls: Only attach to sockets in ESTABLISHED state") > Reported-by: Eric Dumazet <edumazet@google.com> > Signed-off-by: John Fastabend <john.fastabend@gmail.com> Nice, I think we were running into this!
On Wed, 24 Apr 2019 12:21:03 -0700, John Fastabend wrote: > It is possible (via shutdown()) for TCP socks to go through TCP_CLOSE > state via tcp_disconnect() without calling into close callback. This > would allow a kTLS enabled socket to exist outside of ESTABLISHED > state which is not supported. > > Solve this the same way we solved the sock{map|hash} case by adding > an unhash hook to remove tear down the TLS state. > > In the process we also make the close hook more robust. We add a put > call into the close path, also in the unhash path, to remove the > reference to ulp data after free. Its no longer valid and may confuse > things later if the socket (re)enters kTLS code paths. Second we add > an 'if(ctx)' check to ensure the ctx is still valid and not released > from a previous unhash/close path. > > Fixes: d91c3e17f75f2 ("net/tls: Only attach to sockets in ESTABLISHED state") > Reported-by: Eric Dumazet <edumazet@google.com> > Signed-off-by: John Fastabend <john.fastabend@gmail.com> Ah, EDOESNTBUILD, now I get to nitpick too? :) > diff --git a/include/net/tls.h b/include/net/tls.h > index d9d0ac66f040..ae13ea19b375 100644 > --- a/include/net/tls.h > +++ b/include/net/tls.h > @@ -266,6 +266,8 @@ struct tls_context { > void (*sk_write_space)(struct sock *sk); > void (*sk_destruct)(struct sock *sk); > void (*sk_proto_close)(struct sock *sk, long timeout); > + void (*sk_proto_unhash)(struct sock *sk); > + struct proto *sk_proto; > > int (*setsockopt)(struct sock *sk, int level, > int optname, char __user *optval, > @@ -303,7 +305,7 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); > int tls_sw_sendpage(struct sock *sk, struct page *page, > int offset, size_t size, int flags); > void tls_sw_close(struct sock *sk, long timeout); > -void tls_sw_free_resources_tx(struct sock *sk); > +void tls_sw_free_resources_tx(struct sock *sk, bool locked); > void tls_sw_free_resources_rx(struct sock *sk); > void tls_sw_release_resources_rx(struct sock *sk); > int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, > @@ -504,6 +506,16 @@ static inline void xor_iv_with_seq(int version, char *iv, char *seq) > } > } > > +static inline void tls_put_ctx(struct sock *sk) > +{ > + struct inet_connection_sock *icsk = inet_csk(sk); > + struct tls_context *ctx = icsk->icsk_ulp_data; > + > + if (!ctx) > + return; > + sk->sk_prot = ctx->sk_proto; > + icsk->icsk_ulp_data = NULL; > +} > > static inline struct tls_sw_context_rx *tls_sw_ctx_rx( > const struct tls_context *tls_ctx) > diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c > index 7e546b8ec000..2973048957bd 100644 > --- a/net/tls/tls_main.c > +++ b/net/tls/tls_main.c > @@ -261,23 +261,16 @@ static void tls_ctx_free(struct tls_context *ctx) > kfree(ctx); > } > > -static void tls_sk_proto_close(struct sock *sk, long timeout) > +static bool tls_sk_proto_destroy(struct sock *sk, > + struct tls_context *ctx, bool destroy) perhaps this destroy should rather be called locked? It doesn't really control destroying AFACT.. > { > - struct tls_context *ctx = tls_get_ctx(sk); > long timeo = sock_sndtimeo(sk, 0); > - void (*sk_proto_close)(struct sock *sk, long timeout); > - bool free_ctx = false; > - > - lock_sock(sk); > - sk_proto_close = ctx->sk_proto_close; > > if (ctx->tx_conf == TLS_HW_RECORD && ctx->rx_conf == TLS_HW_RECORD) > - goto skip_tx_cleanup; > + return false; > > - if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE) { > - free_ctx = true; > - goto skip_tx_cleanup; > - } > + if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE) > + return true; > > if (!tls_complete_pending_work(sk, ctx, 0, &timeo)) > tls_handle_open_record(sk, 0); > @@ -286,10 +279,10 @@ static void tls_sk_proto_close(struct sock *sk, long timeout) > if (ctx->tx_conf == TLS_SW) { > kfree(ctx->tx.rec_seq); > kfree(ctx->tx.iv); > - tls_sw_free_resources_tx(sk); > + tls_sw_free_resources_tx(sk, destroy); > #ifdef CONFIG_TLS_DEVICE > } else if (ctx->tx_conf == TLS_HW) { > - tls_device_free_resources_tx(sk); > + tls_device_free_resources_tx(sk, destroy); this part breaks the build tls_device_free_resources_tx() doesn't need changes. tls_device_offload_cleanup_rx() will though, cause it sleeps. > #endif > } > > @@ -310,8 +303,39 @@ static void tls_sk_proto_close(struct sock *sk, long timeout) > tls_ctx_free(ctx); > ctx = NULL; > } > + return false; > +} > + > +static void tls_sk_proto_unhash(struct sock *sk) > +{ > + struct tls_context *ctx = tls_get_ctx(sk); > + void (*sk_proto_unhash)(struct sock *sk); > + bool free_ctx; > + > + if (!ctx) > + return sk->sk_prot->unhash(sk); > + sk_proto_unhash = ctx->sk_proto_unhash; > + free_ctx = tls_sk_proto_destroy(sk, ctx, false); > + tls_put_ctx(sk); > + if (sk_proto_unhash) > + sk_proto_unhash(sk); > + if (free_ctx) > + tls_ctx_free(ctx); > +} > > -skip_tx_cleanup: > +static void tls_sk_proto_close(struct sock *sk, long timeout) > +{ > + struct tls_context *ctx = tls_get_ctx(sk); > + void (*sk_proto_close)(struct sock *sk, long timeout); reverse xmas tree > + bool free_ctx; > + > + if (!ctx) > + return sk->sk_prot->destroy(sk); > + > + lock_sock(sk); > + sk_proto_close = ctx->sk_proto_close; > + free_ctx = tls_sk_proto_destroy(sk, ctx, true); > + tls_put_ctx(sk); > release_sock(sk); > sk_proto_close(sk, timeout); > /* free ctx for TLS_HW_RECORD, used by tcp_set_state > @@ -609,6 +633,8 @@ static struct tls_context *create_ctx(struct sock *sk) > ctx->setsockopt = sk->sk_prot->setsockopt; > ctx->getsockopt = sk->sk_prot->getsockopt; > ctx->sk_proto_close = sk->sk_prot->close; > + ctx->sk_proto_unhash = sk->sk_prot->unhash; > + ctx->sk_proto = sk->sk_prot; > return ctx; > } > > @@ -732,6 +758,7 @@ static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG], > prot[TLS_BASE][TLS_BASE].setsockopt = tls_setsockopt; > prot[TLS_BASE][TLS_BASE].getsockopt = tls_getsockopt; > prot[TLS_BASE][TLS_BASE].close = tls_sk_proto_close; > + prot[TLS_BASE][TLS_BASE].unhash = tls_sk_proto_unhash; > > prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE]; > prot[TLS_SW][TLS_BASE].sendmsg = tls_sw_sendmsg; > diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c > index f780b473827b..0577633c319b 100644 > --- a/net/tls/tls_sw.c > +++ b/net/tls/tls_sw.c > @@ -2044,7 +2044,7 @@ static void tls_data_ready(struct sock *sk) > } > } > > -void tls_sw_free_resources_tx(struct sock *sk) > +void tls_sw_free_resources_tx(struct sock *sk, bool locked) > { > struct tls_context *tls_ctx = tls_get_ctx(sk); > struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx); > @@ -2055,9 +2055,11 @@ void tls_sw_free_resources_tx(struct sock *sk) > if (atomic_read(&ctx->encrypt_pending)) > crypto_wait_req(-EINPROGRESS, &ctx->async_wait); > > - release_sock(sk); > + if (locked) > + release_sock(sk); > cancel_delayed_work_sync(&ctx->tx_work.work); > - lock_sock(sk); > + if (locked) > + lock_sock(sk); > > /* Tx whatever records we can transmit and abandon the rest */ > tls_tx_records(sk, -1); > @@ -2080,7 +2082,10 @@ void tls_sw_free_resources_tx(struct sock *sk) > kfree(rec); > } > > - crypto_free_aead(ctx->aead_send); > + if (ctx->aead_send) { > + crypto_free_aead(ctx->aead_send); > + ctx->aead_send = NULL; > + } > tls_free_open_rec(sk); > > kfree(ctx); >
On 4/24/19 8:07 PM, Jakub Kicinski wrote: > On Wed, 24 Apr 2019 12:21:03 -0700, John Fastabend wrote: >> It is possible (via shutdown()) for TCP socks to go through TCP_CLOSE >> state via tcp_disconnect() without calling into close callback. This >> would allow a kTLS enabled socket to exist outside of ESTABLISHED >> state which is not supported. >> >> Solve this the same way we solved the sock{map|hash} case by adding >> an unhash hook to remove tear down the TLS state. >> >> In the process we also make the close hook more robust. We add a put >> call into the close path, also in the unhash path, to remove the >> reference to ulp data after free. Its no longer valid and may confuse >> things later if the socket (re)enters kTLS code paths. Second we add >> an 'if(ctx)' check to ensure the ctx is still valid and not released >> from a previous unhash/close path. >> >> Fixes: d91c3e17f75f2 ("net/tls: Only attach to sockets in ESTABLISHED state") >> Reported-by: Eric Dumazet <edumazet@google.com> >> Signed-off-by: John Fastabend <john.fastabend@gmail.com> > > Ah, EDOESNTBUILD, now I get to nitpick too? :) > Oops messed up a merge conflict. nitpicks seems like a fair enough punishment. # CONFIG_TLS_DEVICE is not set [...] >> static inline struct tls_sw_context_rx *tls_sw_ctx_rx( >> const struct tls_context *tls_ctx) >> diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c >> index 7e546b8ec000..2973048957bd 100644 >> --- a/net/tls/tls_main.c >> +++ b/net/tls/tls_main.c >> @@ -261,23 +261,16 @@ static void tls_ctx_free(struct tls_context *ctx) >> kfree(ctx); >> } >> >> -static void tls_sk_proto_close(struct sock *sk, long timeout) >> +static bool tls_sk_proto_destroy(struct sock *sk, >> + struct tls_context *ctx, bool destroy) > > perhaps this destroy should rather be called locked? It doesn't really > control destroying AFACT.. > Sure we can call it locked. >> { >> - struct tls_context *ctx = tls_get_ctx(sk); >> long timeo = sock_sndtimeo(sk, 0); >> - void (*sk_proto_close)(struct sock *sk, long timeout); >> - bool free_ctx = false; >> - >> - lock_sock(sk); >> - sk_proto_close = ctx->sk_proto_close; >> >> if (ctx->tx_conf == TLS_HW_RECORD && ctx->rx_conf == TLS_HW_RECORD) >> - goto skip_tx_cleanup; >> + return false; >> >> - if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE) { >> - free_ctx = true; >> - goto skip_tx_cleanup; >> - } >> + if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE) >> + return true; >> >> if (!tls_complete_pending_work(sk, ctx, 0, &timeo)) >> tls_handle_open_record(sk, 0); >> @@ -286,10 +279,10 @@ static void tls_sk_proto_close(struct sock *sk, long timeout) >> if (ctx->tx_conf == TLS_SW) { >> kfree(ctx->tx.rec_seq); >> kfree(ctx->tx.iv); >> - tls_sw_free_resources_tx(sk); >> + tls_sw_free_resources_tx(sk, destroy); >> #ifdef CONFIG_TLS_DEVICE >> } else if (ctx->tx_conf == TLS_HW) { >> - tls_device_free_resources_tx(sk); >> + tls_device_free_resources_tx(sk, destroy); > > this part breaks the build tls_device_free_resources_tx() doesn't need > changes. tls_device_offload_cleanup_rx() will though, cause it sleeps. OK will touch that path as well. > >> #endif >> } >> >> @@ -310,8 +303,39 @@ static void tls_sk_proto_close(struct sock *sk, long timeout) >> tls_ctx_free(ctx); >> ctx = NULL; >> } >> + return false; >> +} >> + >> +static void tls_sk_proto_unhash(struct sock *sk) >> +{ >> + struct tls_context *ctx = tls_get_ctx(sk); >> + void (*sk_proto_unhash)(struct sock *sk); >> + bool free_ctx; >> + >> + if (!ctx) >> + return sk->sk_prot->unhash(sk); >> + sk_proto_unhash = ctx->sk_proto_unhash; >> + free_ctx = tls_sk_proto_destroy(sk, ctx, false); >> + tls_put_ctx(sk); >> + if (sk_proto_unhash) >> + sk_proto_unhash(sk); >> + if (free_ctx) >> + tls_ctx_free(ctx); >> +} >> >> -skip_tx_cleanup: >> +static void tls_sk_proto_close(struct sock *sk, long timeout) >> +{ >> + struct tls_context *ctx = tls_get_ctx(sk); >> + void (*sk_proto_close)(struct sock *sk, long timeout); > > reverse xmas tree > +1 >> + bool free_ctx; >> + >> + if (!ctx) >> + return sk->sk_prot->destroy(sk); >> + >> + lock_sock(sk); >> + sk_proto_close = ctx->sk_proto_close; >> + free_ctx = tls_sk_proto_destroy(sk, ctx, true); >> + tls_put_ctx(sk); >> release_sock(sk); >> sk_proto_close(sk, timeout); >> /* free ctx for TLS_HW_RECORD, used by tcp_set_state Thanks for reviewing.
diff --git a/include/net/tls.h b/include/net/tls.h index d9d0ac66f040..ae13ea19b375 100644 --- a/include/net/tls.h +++ b/include/net/tls.h @@ -266,6 +266,8 @@ struct tls_context { void (*sk_write_space)(struct sock *sk); void (*sk_destruct)(struct sock *sk); void (*sk_proto_close)(struct sock *sk, long timeout); + void (*sk_proto_unhash)(struct sock *sk); + struct proto *sk_proto; int (*setsockopt)(struct sock *sk, int level, int optname, char __user *optval, @@ -303,7 +305,7 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); int tls_sw_sendpage(struct sock *sk, struct page *page, int offset, size_t size, int flags); void tls_sw_close(struct sock *sk, long timeout); -void tls_sw_free_resources_tx(struct sock *sk); +void tls_sw_free_resources_tx(struct sock *sk, bool locked); void tls_sw_free_resources_rx(struct sock *sk); void tls_sw_release_resources_rx(struct sock *sk); int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, @@ -504,6 +506,16 @@ static inline void xor_iv_with_seq(int version, char *iv, char *seq) } } +static inline void tls_put_ctx(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tls_context *ctx = icsk->icsk_ulp_data; + + if (!ctx) + return; + sk->sk_prot = ctx->sk_proto; + icsk->icsk_ulp_data = NULL; +} static inline struct tls_sw_context_rx *tls_sw_ctx_rx( const struct tls_context *tls_ctx) diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c index 7e546b8ec000..2973048957bd 100644 --- a/net/tls/tls_main.c +++ b/net/tls/tls_main.c @@ -261,23 +261,16 @@ static void tls_ctx_free(struct tls_context *ctx) kfree(ctx); } -static void tls_sk_proto_close(struct sock *sk, long timeout) +static bool tls_sk_proto_destroy(struct sock *sk, + struct tls_context *ctx, bool destroy) { - struct tls_context *ctx = tls_get_ctx(sk); long timeo = sock_sndtimeo(sk, 0); - void (*sk_proto_close)(struct sock *sk, long timeout); - bool free_ctx = false; - - lock_sock(sk); - sk_proto_close = ctx->sk_proto_close; if (ctx->tx_conf == TLS_HW_RECORD && ctx->rx_conf == TLS_HW_RECORD) - goto skip_tx_cleanup; + return false; - if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE) { - free_ctx = true; - goto skip_tx_cleanup; - } + if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE) + return true; if (!tls_complete_pending_work(sk, ctx, 0, &timeo)) tls_handle_open_record(sk, 0); @@ -286,10 +279,10 @@ static void tls_sk_proto_close(struct sock *sk, long timeout) if (ctx->tx_conf == TLS_SW) { kfree(ctx->tx.rec_seq); kfree(ctx->tx.iv); - tls_sw_free_resources_tx(sk); + tls_sw_free_resources_tx(sk, destroy); #ifdef CONFIG_TLS_DEVICE } else if (ctx->tx_conf == TLS_HW) { - tls_device_free_resources_tx(sk); + tls_device_free_resources_tx(sk, destroy); #endif } @@ -310,8 +303,39 @@ static void tls_sk_proto_close(struct sock *sk, long timeout) tls_ctx_free(ctx); ctx = NULL; } + return false; +} + +static void tls_sk_proto_unhash(struct sock *sk) +{ + struct tls_context *ctx = tls_get_ctx(sk); + void (*sk_proto_unhash)(struct sock *sk); + bool free_ctx; + + if (!ctx) + return sk->sk_prot->unhash(sk); + sk_proto_unhash = ctx->sk_proto_unhash; + free_ctx = tls_sk_proto_destroy(sk, ctx, false); + tls_put_ctx(sk); + if (sk_proto_unhash) + sk_proto_unhash(sk); + if (free_ctx) + tls_ctx_free(ctx); +} -skip_tx_cleanup: +static void tls_sk_proto_close(struct sock *sk, long timeout) +{ + struct tls_context *ctx = tls_get_ctx(sk); + void (*sk_proto_close)(struct sock *sk, long timeout); + bool free_ctx; + + if (!ctx) + return sk->sk_prot->destroy(sk); + + lock_sock(sk); + sk_proto_close = ctx->sk_proto_close; + free_ctx = tls_sk_proto_destroy(sk, ctx, true); + tls_put_ctx(sk); release_sock(sk); sk_proto_close(sk, timeout); /* free ctx for TLS_HW_RECORD, used by tcp_set_state @@ -609,6 +633,8 @@ static struct tls_context *create_ctx(struct sock *sk) ctx->setsockopt = sk->sk_prot->setsockopt; ctx->getsockopt = sk->sk_prot->getsockopt; ctx->sk_proto_close = sk->sk_prot->close; + ctx->sk_proto_unhash = sk->sk_prot->unhash; + ctx->sk_proto = sk->sk_prot; return ctx; } @@ -732,6 +758,7 @@ static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG], prot[TLS_BASE][TLS_BASE].setsockopt = tls_setsockopt; prot[TLS_BASE][TLS_BASE].getsockopt = tls_getsockopt; prot[TLS_BASE][TLS_BASE].close = tls_sk_proto_close; + prot[TLS_BASE][TLS_BASE].unhash = tls_sk_proto_unhash; prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE]; prot[TLS_SW][TLS_BASE].sendmsg = tls_sw_sendmsg; diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index f780b473827b..0577633c319b 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -2044,7 +2044,7 @@ static void tls_data_ready(struct sock *sk) } } -void tls_sw_free_resources_tx(struct sock *sk) +void tls_sw_free_resources_tx(struct sock *sk, bool locked) { struct tls_context *tls_ctx = tls_get_ctx(sk); struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx); @@ -2055,9 +2055,11 @@ void tls_sw_free_resources_tx(struct sock *sk) if (atomic_read(&ctx->encrypt_pending)) crypto_wait_req(-EINPROGRESS, &ctx->async_wait); - release_sock(sk); + if (locked) + release_sock(sk); cancel_delayed_work_sync(&ctx->tx_work.work); - lock_sock(sk); + if (locked) + lock_sock(sk); /* Tx whatever records we can transmit and abandon the rest */ tls_tx_records(sk, -1); @@ -2080,7 +2082,10 @@ void tls_sw_free_resources_tx(struct sock *sk) kfree(rec); } - crypto_free_aead(ctx->aead_send); + if (ctx->aead_send) { + crypto_free_aead(ctx->aead_send); + ctx->aead_send = NULL; + } tls_free_open_rec(sk); kfree(ctx);
It is possible (via shutdown()) for TCP socks to go through TCP_CLOSE state via tcp_disconnect() without calling into close callback. This would allow a kTLS enabled socket to exist outside of ESTABLISHED state which is not supported. Solve this the same way we solved the sock{map|hash} case by adding an unhash hook to remove tear down the TLS state. In the process we also make the close hook more robust. We add a put call into the close path, also in the unhash path, to remove the reference to ulp data after free. Its no longer valid and may confuse things later if the socket (re)enters kTLS code paths. Second we add an 'if(ctx)' check to ensure the ctx is still valid and not released from a previous unhash/close path. Fixes: d91c3e17f75f2 ("net/tls: Only attach to sockets in ESTABLISHED state") Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: John Fastabend <john.fastabend@gmail.com> --- include/net/tls.h | 14 ++++++++++++- net/tls/tls_main.c | 57 ++++++++++++++++++++++++++++++++++++++-------------- net/tls/tls_sw.c | 13 ++++++++---- 3 files changed, 64 insertions(+), 20 deletions(-)