From a0df71948e9548de819a6f1da68f5f1742258a52 Mon Sep 17 00:00:00 2001 From: Maxim Mikityanskiy Date: Tue, 26 Apr 2022 18:49:49 +0300 Subject: [PATCH] tls: Skip tls_append_frag on zero copy size Calling tls_append_frag when max_open_record_len == record->len might add an empty fragment to the TLS record if the call happens to be on the page boundary. Normally tls_append_frag coalesces the zero-sized fragment to the previous one, but not if it's on page boundary. If a resync happens then, the mlx5 driver posts dump WQEs in tx_post_resync_dump, and the empty fragment may become a data segment with byte_count == 0, which will confuse the NIC and lead to a CQE error. This commit fixes the described issue by skipping tls_append_frag on zero size to avoid adding empty fragments. The fix is not in the driver, because an empty fragment is hardly the desired behavior. Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure") Signed-off-by: Maxim Mikityanskiy Reviewed-by: Tariq Toukan Link: https://lore.kernel.org/r/20220426154949.159055-1-maximmi@nvidia.com Signed-off-by: Jakub Kicinski --- net/tls/tls_device.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c index 12f7b56771d9..af875ad4a822 100644 --- a/net/tls/tls_device.c +++ b/net/tls/tls_device.c @@ -483,11 +483,13 @@ handle_error: copy = min_t(size_t, size, (pfrag->size - pfrag->offset)); copy = min_t(size_t, copy, (max_open_record_len - record->len)); - rc = tls_device_copy_data(page_address(pfrag->page) + - pfrag->offset, copy, msg_iter); - if (rc) - goto handle_error; - tls_append_frag(record, pfrag, copy); + if (copy) { + rc = tls_device_copy_data(page_address(pfrag->page) + + pfrag->offset, copy, msg_iter); + if (rc) + goto handle_error; + tls_append_frag(record, pfrag, copy); + } size -= copy; if (!size) { -- 2.20.1