2019-03-26 02:07:15

by Peng Hao

[permalink] [raw]
Subject: [PATCH v3] powerpc/8xx: fix possible object reference leak

From: Wen Yang <[email protected]>

The call to of_find_compatible_node returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.
irq_domain_add_linear also calls of_node_get to increase refcount,
so irq_domain will not be affected when it is released.

Detected by coccinelle with the following warnings:
./arch/powerpc/platforms/8xx/pic.c:158:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 136, but without a corresponding object release within this function.

Fixes: a8db8cf0d894 ("irq_domain: Replace irq_alloc_host() with
revmap-specific initializers")
Signed-off-by: Wen Yang <[email protected]>
Suggested-by: Christophe Leroy <[email protected]>
Suggested-by: Michael Ellerman <[email protected]>
Reviewed-by: Peng Hao <[email protected]>
Reviewed-by: Christophe Leroy <[email protected]>
Cc: Vitaly Bordug <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
v3->v2: set ret to zero explicitly.
v2->v1: add a Fixes tag.

arch/powerpc/platforms/8xx/pic.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/8xx/pic.c b/arch/powerpc/platforms/8xx/pic.c
index 8d5a25d..9993998 100644
--- a/arch/powerpc/platforms/8xx/pic.c
+++ b/arch/powerpc/platforms/8xx/pic.c
@@ -153,9 +153,9 @@ int mpc8xx_pic_init(void)
if (mpc8xx_pic_host == NULL) {
printk(KERN_ERR "MPC8xx PIC: failed to allocate irq host!\n");
ret = -ENOMEM;
- goto out;
}
- return 0;
+
+ ret = 0;

out:
of_node_put(np);
--
2.9.5



2019-03-26 06:06:19

by Christophe Leroy

[permalink] [raw]
Subject: Re: [PATCH v3] powerpc/8xx: fix possible object reference leak



Le 26/03/2019 à 11:29, Peng Hao a écrit :

Could you fix your clock or clock setup ?

This emails appears to have been sent today at 11:29 (Paris Time ie
GMT+1) allthough it is only 7am at the time being.

Christophe

> From: Wen Yang <[email protected]>
>
> The call to of_find_compatible_node returns a node pointer with refcount
> incremented thus it must be explicitly decremented after the last
> usage.
> irq_domain_add_linear also calls of_node_get to increase refcount,
> so irq_domain will not be affected when it is released.
>
> Detected by coccinelle with the following warnings:
> ./arch/powerpc/platforms/8xx/pic.c:158:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 136, but without a corresponding object release within this function.
>
> Fixes: a8db8cf0d894 ("irq_domain: Replace irq_alloc_host() with
> revmap-specific initializers")
> Signed-off-by: Wen Yang <[email protected]>
> Suggested-by: Christophe Leroy <[email protected]>
> Suggested-by: Michael Ellerman <[email protected]>
> Reviewed-by: Peng Hao <[email protected]>
> Reviewed-by: Christophe Leroy <[email protected]>
> Cc: Vitaly Bordug <[email protected]>
> Cc: Benjamin Herrenschmidt <[email protected]>
> Cc: Paul Mackerras <[email protected]>
> Cc: Michael Ellerman <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> ---
> v3->v2: set ret to zero explicitly.
> v2->v1: add a Fixes tag.
>
> arch/powerpc/platforms/8xx/pic.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/platforms/8xx/pic.c b/arch/powerpc/platforms/8xx/pic.c
> index 8d5a25d..9993998 100644
> --- a/arch/powerpc/platforms/8xx/pic.c
> +++ b/arch/powerpc/platforms/8xx/pic.c
> @@ -153,9 +153,9 @@ int mpc8xx_pic_init(void)
> if (mpc8xx_pic_host == NULL) {
> printk(KERN_ERR "MPC8xx PIC: failed to allocate irq host!\n");
> ret = -ENOMEM;
> - goto out;
> }
> - return 0;
> +
> + ret = 0;
>
> out:
> of_node_put(np);
>

2019-04-21 14:20:55

by Michael Ellerman

[permalink] [raw]
Subject: Re: [v3] powerpc/8xx: fix possible object reference leak

On Tue, 2019-03-26 at 10:29:51 UTC, Peng Hao wrote:
> From: Wen Yang <[email protected]>
>
> The call to of_find_compatible_node returns a node pointer with refcount
> incremented thus it must be explicitly decremented after the last
> usage.
> irq_domain_add_linear also calls of_node_get to increase refcount,
> so irq_domain will not be affected when it is released.
>
> Detected by coccinelle with the following warnings:
> ./arch/powerpc/platforms/8xx/pic.c:158:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 136, but without a corresponding object release within this function.
>
> Fixes: a8db8cf0d894 ("irq_domain: Replace irq_alloc_host() with
> revmap-specific initializers")
> Signed-off-by: Wen Yang <[email protected]>
> Suggested-by: Christophe Leroy <[email protected]>
> Suggested-by: Michael Ellerman <[email protected]>
> Reviewed-by: Peng Hao <[email protected]>
> Reviewed-by: Christophe Leroy <[email protected]>
> Cc: Vitaly Bordug <[email protected]>
> Cc: Benjamin Herrenschmidt <[email protected]>
> Cc: Paul Mackerras <[email protected]>
> Cc: Michael Ellerman <[email protected]>
> Cc: [email protected]
> Cc: [email protected]

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/cc76404feaed597bb4f5234d34d3f49e

cheers