2020-02-02 20:21:24

by Christophe JAILLET

Subject: [PATCH] MIPS: VPE: Fix a double free and a memory leak in 'release_vpe()'

Pointer on the memory allocated by 'alloc_progmem()' is stored in
'v->load_addr'. So this is this memory that should be freed by
'release_progmem()'.

'release_progmem()' is only a call to 'kfree()'.

With the current code, there is both a double free and a memory leak.
Fix it by passing the correct pointer to 'release_progmem()'.

Fixes: e01402b115ccc ("More AP / SP bits for the 34K, the Malta bits and things. Still wants")
Signed-off-by: Christophe JAILLET <[email protected]>
---
Un-tested

The 'if (v->load_addr)' looks also redundant, but, well, the code is old
and I feel lazy tonight to send another patch for only that.
---
arch/mips/kernel/vpe.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/kernel/vpe.c b/arch/mips/kernel/vpe.c
index 6176b9acba95..d0d832ab3d3b 100644
--- a/arch/mips/kernel/vpe.c
+++ b/arch/mips/kernel/vpe.c
@@ -134,7 +134,7 @@ void release_vpe(struct vpe *v)
{
list_del(&v->list);
if (v->load_addr)
- release_progmem(v);
+ release_progmem(v->load_addr);
kfree(v);
}

--
2.20.1

2020-02-15 22:59:53

by Paul Burton

Subject: Re: [PATCH] MIPS: VPE: Fix a double free and a memory leak in 'release_vpe()'

Hello,

Christophe JAILLET wrote:
> Pointer on the memory allocated by 'alloc_progmem()' is stored in
> 'v->load_addr'. So this is this memory that should be freed by
> 'release_progmem()'.
>
> 'release_progmem()' is only a call to 'kfree()'.
>
> With the current code, there is both a double free and a memory leak.
> Fix it by passing the correct pointer to 'release_progmem()'.

Applied to mips-fixes.

> commit bef8e2dfceed
> https://git.kernel.org/mips/c/bef8e2dfceed
>
> Fixes: e01402b115ccc ("More AP / SP bits for the 34K, the Malta bits and things. Still wants")
> Signed-off-by: Christophe JAILLET <[email protected]>
> Signed-off-by: Paul Burton <[email protected]>

Thanks,
Paul

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