From 4504ab0e6eb801555368cbb3011ab0530f659d4b Mon Sep 17 00:00:00 2001 From: Vakul Garg Date: Tue, 12 Mar 2019 08:22:57 +0000 Subject: [PATCH] net/tls: Inform user space about send buffer availability A previous fix ("tls: Fix write space handling") assumed that user space application gets informed about the socket send buffer availability when tls_push_sg() gets called. Inside tls_push_sg(), in case do_tcp_sendpages() returns 0, the function returns without calling ctx->sk_write_space. Further, the new function tls_sw_write_space() did not invoke ctx->sk_write_space. This leads to situation that user space application encounters a lockup always waiting for socket send buffer to become available. Rather than call ctx->sk_write_space from tls_push_sg(), it should be called from tls_write_space. So whenever tcp stack invokes sk->sk_write_space after freeing socket send buffer, we always declare the same to user space by the way of invoking ctx->sk_write_space. Fixes: 7463d3a2db0ef ("tls: Fix write space handling") Signed-off-by: Vakul Garg Reviewed-by: Boris Pismenny Signed-off-by: David S. Miller --- net/tls/tls_device.c | 3 --- net/tls/tls_main.c | 3 ++- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c index 4a1da837a733..135a7ee9db03 100644 --- a/net/tls/tls_device.c +++ b/net/tls/tls_device.c @@ -558,9 +558,6 @@ void tls_device_write_space(struct sock *sk, struct tls_context *ctx) MSG_DONTWAIT | MSG_NOSIGNAL); sk->sk_allocation = sk_allocation; } - - if (!rc) - ctx->sk_write_space(sk); } void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn) diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c index 17e8667917aa..df921a2904b9 100644 --- a/net/tls/tls_main.c +++ b/net/tls/tls_main.c @@ -146,7 +146,6 @@ retry: } ctx->in_tcp_sendpages = false; - ctx->sk_write_space(sk); return 0; } @@ -228,6 +227,8 @@ static void tls_write_space(struct sock *sk) else #endif tls_sw_write_space(sk, ctx); + + ctx->sk_write_space(sk); } static void tls_ctx_free(struct tls_context *ctx) -- 2.30.2