net: tls: fix device-offloaded sendpage straddling records

Adrien reports that incorrect data is transmitted when a single
page straddles multiple records. We would transmit the same
data in all iterations of the loop.

Reported-by: Adrien Moulin <amoulin@corp.free.fr>
Link: https://lore.kernel.org/all/61481278.42813558.1677845235112.JavaMail.zimbra@corp.free.fr
Fixes: c1318b39c7d3 ("tls: Add opt-in zerocopy mode of sendfile()")
Tested-by: Adrien Moulin <amoulin@corp.free.fr>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Acked-by: Maxim Mikityanskiy <maxtram95@gmail.com>
Link: https://lore.kernel.org/r/20230304192610.3818098-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 6c59378..a7cc4f9 100644 (file)
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -508,6 +508,8 @@ handle_error:
                        zc_pfrag.offset = iter_offset.offset;
                        zc_pfrag.size = copy;
                        tls_append_frag(record, &zc_pfrag, copy);
+
+                       iter_offset.offset += copy;
                } else if (copy) {
                        copy = min_t(size_t, copy, pfrag->size - pfrag->offset);