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

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 <redacted>
---
 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 7760a3394e93..7ecb3dfe30bd 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_minidump.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_minidump.c

@@ -1425,6 +1425,7 @@ 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);

@@ -1443,6 +1444,8 @@ 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,

-- 
2.25.1

Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Wed, 10 Mar 2021 20:01:40 -0800 you wrote:

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 <redacted>
---
 drivers/net/ethernet/qlogic/qlcnic/qlcnic_minidump.c | 3 +++
 1 file changed, 3 insertions(+)

Here is the summary with links:
  - net/qlcnic: Fix a use after free in qlcnic_83xx_get_minidump_template
    https://git.kernel.org/netdev/net/c/db74623a3850

You are awesome, thank you!
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