2009-12-21 04:38:43

by Darren Jenkins

Subject: drivers/edac/ move a kfree() to after last use

Move a kfree() below the last use of the memory

Coverity CID: 13142

Signed-off-by: Darren Jenkins <[email protected]>
diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index df5b684..15b8b3c 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -2925,10 +2925,10 @@ static void __devexit
amd64_remove_one_instance(struct pci_dev *pdev)

amd64_free_mc_sibling_devices(pvt);

- kfree(pvt);
mci->pvt_info = NULL;

mci_lookup[pvt->mc_node_id] = NULL;
+ kfree(pvt);

/* unregister from EDAC MCE */
amd_report_gart_errors(false);

2009-12-21 15:18:17

by tip-bot for Borislav Petkov

Subject: Re: drivers/edac/ move a kfree() to after last use

On Mon, Dec 21, 2009 at 03:38:26PM +1100, Darren Jenkins wrote:
>
> Move a kfree() below the last use of the memory
>
> Coverity CID: 13142
>
> Signed-off-by: Darren Jenkins <[email protected]>

Thanks for catching that. Here's a better version that does all the
freeing at the end of the function.

--
From: Borislav Petkov <[email protected]>
Date: Mon, 21 Dec 2009 15:15:59 +0100
Subject: [PATCH] amd64_edac: fix driver instance freeing

Fix use-after-free errors by pushing all memory-freeing calls to the end
of amd64_remove_one_instance().

Reported-by: Darren Jenkins <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
---
drivers/edac/amd64_edac.c | 9 ++++-----
1 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index 784cc5a..fb0d36b 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -2929,16 +2929,15 @@ static void __devexit amd64_remove_one_instance(struct pci_dev *pdev)

amd64_free_mc_sibling_devices(pvt);

- kfree(pvt);
- mci->pvt_info = NULL;
-
- mci_lookup[pvt->mc_node_id] = NULL;
-
/* unregister from EDAC MCE */
amd_report_gart_errors(false);
amd_unregister_ecc_decoder(amd64_decode_bus_error);

/* Free the EDAC CORE resources */
+ mci->pvt_info = NULL;
+ mci_lookup[pvt->mc_node_id] = NULL;
+
+ kfree(pvt);
edac_mc_free(mci);
}

--
1.6.5.4


--
Regards/Gruss,
Boris.

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