[PATCH 5.5 110/176] MIPS: VPE: Fix a double free and a memory leak in release_vpe()

[PATCH 5.5 110/176] MIPS: VPE: Fix a double free and a memory leak in release_vpe()

[Greg Kroah-Hartman]

From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

commit bef8e2dfceed6daeb6ca3e8d33f9c9d43b926580 upstream.

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 <christophe.jaillet@wanadoo.fr>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: ralf@linux-mips.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/vpe.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 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);
 }
 

[PATCH 5.5 114/176] MIPS: cavium_octeon: Fix syncw generation.

[Greg Kroah-Hartman]

From: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>

commit 97e914b7de3c943011779b979b8093fdc0d85722 upstream.

The Cavium Octeon CPU uses a special sync instruction for implementing
wmb, and due to a CPU bug, the instruction must appear twice. A macro
had been defined to hide this:

 #define __SYNC_rpt(type)     (1 + (type == __SYNC_wmb))

which was intended to evaluate to 2 for __SYNC_wmb, and 1 for any other
type of sync. However, this expression is evaluated by the assembler,
and not the compiler, and the result of '==' in the assembler is 0 or
-1, not 0 or 1 as it is in C. The net result was wmb() producing no code
at all. The simple fix in this patch is to change the '+' to '-'.

Fixes: bf92927251b3 ("MIPS: barrier: Add __SYNC() infrastructure")
Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/include/asm/sync.h |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/arch/mips/include/asm/sync.h
+++ b/arch/mips/include/asm/sync.h
@@ -155,9 +155,11 @@
  * effective barrier as noted by commit 6b07d38aaa52 ("MIPS: Octeon: Use
  * optimized memory barrier primitives."). Here we specify that the affected
  * sync instructions should be emitted twice.
+ * Note that this expression is evaluated by the assembler (not the compiler),
+ * and that the assembler evaluates '==' as 0 or -1, not 0 or 1.
  */
 #ifdef CONFIG_CPU_CAVIUM_OCTEON
-# define __SYNC_rpt(type)	(1 + (type == __SYNC_wmb))
+# define __SYNC_rpt(type)	(1 - (type == __SYNC_wmb))
 #else
 # define __SYNC_rpt(type)	1
 #endif

AW: [PATCH 5.5 110/176] MIPS: VPE: Fix a double free and a memory leak in release_vpe()

[Walter Harms]

________________________________________
Von: kernel-janitors-owner@vger.kernel.org <kernel-janitors-owner@vger.kernel.org> im Auftrag von Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Gesendet: Dienstag, 3. März 2020 18:42
An: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman; stable@vger.kernel.org; Christophe JAILLET; Paul Burton; ralf@linux-mips.org; linux-mips@vger.kernel.org; kernel-janitors@vger.kernel.org
Betreff: [PATCH 5.5 110/176] MIPS: VPE: Fix a double free and a memory leak in release_vpe()

From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

commit bef8e2dfceed6daeb6ca3e8d33f9c9d43b926580 upstream.

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 <christophe.jaillet@wanadoo.fr>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: ralf@linux-mips.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/vpe.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 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);
 }


since release_progmem() is kfree() it is also possible to drop "if (v->load_addr)"

jm2c

re,
 wh

Re: AW: [PATCH 5.5 110/176] MIPS: VPE: Fix a double free and a memory leak in release_vpe()

[Christophe JAILLET]

Le 04/03/2020 à 22:28, Walter Harms a écrit :
> ________________________________________
> Von: kernel-janitors-owner@vger.kernel.org <kernel-janitors-owner@vger.kernel.org> im Auftrag von Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Gesendet: Dienstag, 3. März 2020 18:42
> An: linux-kernel@vger.kernel.org
> Cc: Greg Kroah-Hartman; stable@vger.kernel.org; Christophe JAILLET; Paul Burton; ralf@linux-mips.org; linux-mips@vger.kernel.org; kernel-janitors@vger.kernel.org
> Betreff: [PATCH 5.5 110/176] MIPS: VPE: Fix a double free and a memory leak in release_vpe()
>
> From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
>
> commit bef8e2dfceed6daeb6ca3e8d33f9c9d43b926580 upstream.
>
> 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 <christophe.jaillet@wanadoo.fr>
> Signed-off-by: Paul Burton <paulburton@kernel.org>
> Cc: ralf@linux-mips.org
> Cc: linux-mips@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: kernel-janitors@vger.kernel.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>
> ---
>   arch/mips/kernel/vpe.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- 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);
>   }
>
>
> since release_progmem() is kfree() it is also possible to drop "if (v->load_addr)"
>
> jm2c
>
> re,
>   wh

Agreed.

My patch had the following comment after the patch description:
---
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.
---

git log shows nearly no update since end of 2015, so I kept my proposal 
as minimal :)

CJ