[PATCH 4.4 23/33] net/qlcnic: Fix a use after free in qlcnic_83xx_get_minidump_template

[Greg Kroah-Hartman]

From: Lv Yunlong <lyl2...@mail.ustc.edu.cn>

[ Upstream commit db74623a3850db99cb9692fda9e836a56b74198d ]

In qlcnic_83xx_get_minidump_template, fw_dump->tmpl_hdr was freed by
vfree(). But unfortunately, it is used when extended is true.

Fixes: 7061b2bdd620e ("qlogic: Deletion of unnecessary checks before two 
function calls")
Signed-off-by: Lv Yunlong <lyl2...@mail.ustc.edu.cn>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/net/ethernet/qlogic/qlcnic/qlcnic_minidump.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_minidump.c 
b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_minidump.c
index 5174e0bd75d1..625336264a44 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_minidump.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_minidump.c
@@ -1426,6 +1426,7 @@ void qlcnic_83xx_get_minidump_template(struct 
qlcnic_adapter *adapter)
 
        if (fw_dump->tmpl_hdr == NULL || current_version > prev_version) {
                vfree(fw_dump->tmpl_hdr);
+               fw_dump->tmpl_hdr = NULL;
 
                if (qlcnic_83xx_md_check_extended_dump_capability(adapter))
                        extended = !qlcnic_83xx_extend_md_capab(adapter);
@@ -1444,6 +1445,8 @@ void qlcnic_83xx_get_minidump_template(struct 
qlcnic_adapter *adapter)
                        struct qlcnic_83xx_dump_template_hdr *hdr;
 
                        hdr = fw_dump->tmpl_hdr;
+                       if (!hdr)
+                               return;
                        hdr->drv_cap_mask = 0x1f;
                        fw_dump->cap_mask = 0x1f;
                        dev_info(&pdev->dev,
-- 
2.30.1