Patch "net: qed: Fix memcpy() overflow of qed_dcbx_params()" has been added to the 5.12-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    net: qed: Fix memcpy() overflow of qed_dcbx_params()

to the 5.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-qed-fix-memcpy-overflow-of-qed_dcbx_params.patch
and it can be found in the queue-5.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 8f6f89928e90bab6bf606a3c10b5116cfe4a6941
Author: Kees Cook <keescook@xxxxxxxxxxxx>
Date:   Thu Jun 17 10:09:53 2021 -0700

    net: qed: Fix memcpy() overflow of qed_dcbx_params()
    
    [ Upstream commit 1c200f832e14420fa770193f9871f4ce2df00d07 ]
    
    The source (&dcbx_info->operational.params) and dest
    (&p_hwfn->p_dcbx_info->set.config.params) are both struct qed_dcbx_params
    (560 bytes), not struct qed_dcbx_admin_params (564 bytes), which is used
    as the memcpy() size.
    
    However it seems that struct qed_dcbx_operational_params
    (dcbx_info->operational)'s layout matches struct qed_dcbx_admin_params
    (p_hwfn->p_dcbx_info->set.config)'s 4 byte difference (3 padding, 1 byte
    for "valid").
    
    On the assumption that the size is wrong (rather than the source structure
    type), adjust the memcpy() size argument to be 4 bytes smaller and add
    a BUILD_BUG_ON() to validate any changes to the structure sizes.
    
    Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/qlogic/qed/qed_dcbx.c b/drivers/net/ethernet/qlogic/qed/qed_dcbx.c
index 17d5b649eb36..e81dd34a3cac 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_dcbx.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_dcbx.c
@@ -1266,9 +1266,11 @@ int qed_dcbx_get_config_params(struct qed_hwfn *p_hwfn,
 		p_hwfn->p_dcbx_info->set.ver_num |= DCBX_CONFIG_VERSION_STATIC;
 
 	p_hwfn->p_dcbx_info->set.enabled = dcbx_info->operational.enabled;
+	BUILD_BUG_ON(sizeof(dcbx_info->operational.params) !=
+		     sizeof(p_hwfn->p_dcbx_info->set.config.params));
 	memcpy(&p_hwfn->p_dcbx_info->set.config.params,
 	       &dcbx_info->operational.params,
-	       sizeof(struct qed_dcbx_admin_params));
+	       sizeof(p_hwfn->p_dcbx_info->set.config.params));
 	p_hwfn->p_dcbx_info->set.config.valid = true;
 
 	memcpy(params, &p_hwfn->p_dcbx_info->set, sizeof(struct qed_dcbx_set));