2018-06-01 04:52:52

by Zhenzhong Duan

Subject: [PATCH] x86/microcode/intel: Fix memleak in save_microcode_patch

Free useless ucode_patch entry when it's replaced.

Signed-off-by: Zhenzhong Duan <[email protected]>
---
arch/x86/kernel/cpu/microcode/intel.c | 10 +++++++++-
1 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 1c2cfa0..461e315 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -150,6 +150,12 @@ static bool microcode_matches(struct microcode_header_intel *mc_header,
return false;
}

+static void memfree_patch(struct ucode_patch *p)
+{
+ kfree(p->data);
+ kfree(p);
+}
+
static struct ucode_patch *memdup_patch(void *data, unsigned int size)
{
struct ucode_patch *p;
@@ -190,8 +196,10 @@ static void save_microcode_patch(void *data, unsigned int size)
p = memdup_patch(data, size);
if (!p)
pr_err("Error allocating buffer %p\n", data);
- else
+ else {
list_replace(&iter->plist, &p->plist);
+ memfree_patch(iter);
+ }
}
}

--
1.7.1

2018-06-01 07:13:59

by Borislav Petkov

Subject: Re: [PATCH] x86/microcode/intel: Fix memleak in save_microcode_patch

On Thu, May 31, 2018 at 09:51:05PM -0700, Zhenzhong Duan wrote:
> Free useless ucode_patch entry when it's replaced.
>
> Signed-off-by: Zhenzhong Duan <[email protected]>
> ---
> arch/x86/kernel/cpu/microcode/intel.c | 10 +++++++++-
> 1 files changed, 9 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
> index 1c2cfa0..461e315 100644
> --- a/arch/x86/kernel/cpu/microcode/intel.c
> +++ b/arch/x86/kernel/cpu/microcode/intel.c
> @@ -150,6 +150,12 @@ static bool microcode_matches(struct microcode_header_intel *mc_header,
> return false;
> }
>
> +static void memfree_patch(struct ucode_patch *p)
> +{
> + kfree(p->data);
> + kfree(p);
> +}
> +
> static struct ucode_patch *memdup_patch(void *data, unsigned int size)
> {
> struct ucode_patch *p;
> @@ -190,8 +196,10 @@ static void save_microcode_patch(void *data, unsigned int size)
> p = memdup_patch(data, size);
> if (!p)
> pr_err("Error allocating buffer %p\n", data);
> - else
> + else {
> list_replace(&iter->plist, &p->plist);
> + memfree_patch(iter);

Looks correct. I've dropped the memfree_patch() two-liner though and
made it do kfree() directly.

Thx.

--
Regards/Gruss,
Boris.

ECO tip #101: Trim your mails when you reply.
--

2018-06-22 12:47:47

by tip-bot for Vasyl Gomonovych

Subject: [tip:x86/urgent] x86/microcode/intel: Fix memleak in save_microcode_patch()

Commit-ID: 0218c766263e70795c5eaa17d75ed54bca350950
Gitweb: https://git.kernel.org/tip/0218c766263e70795c5eaa17d75ed54bca350950
Author: Zhenzhong Duan <[email protected]>
AuthorDate: Fri, 22 Jun 2018 13:51:26 +0200
Committer: Thomas Gleixner <[email protected]>
CommitDate: Fri, 22 Jun 2018 14:42:59 +0200

x86/microcode/intel: Fix memleak in save_microcode_patch()

Free useless ucode_patch entry when it's replaced.

[ bp: Drop the memfree_patch() two-liner. ]

Signed-off-by: Zhenzhong Duan <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Srinivas REDDY Eeda <[email protected]>
Link: http://lkml.kernel.org/r/888102f0-fd22-459d-b090-a1bd8a00cb2b@default

---
arch/x86/kernel/cpu/microcode/intel.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 1c2cfa0644aa..97ccf4c3b45b 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -190,8 +190,11 @@ static void save_microcode_patch(void *data, unsigned int size)
p = memdup_patch(data, size);
if (!p)
pr_err("Error allocating buffer %p\n", data);
- else
+ else {
list_replace(&iter->plist, &p->plist);
+ kfree(iter->data);
+ kfree(iter);
+ }
}
}