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* [PATCH v2] md: add mddev->pers to avoid potential NULL pointer dereference
@ 2019-04-02  6:22 ` Yufen Yu
  0 siblings, 0 replies; 4+ messages in thread
From: Yufen Yu @ 2019-04-02  6:22 UTC (permalink / raw)
  To: axboe, songliubraving; +Cc: neilb, xni, linux-raid, stable

When doing re-add, we need to ensure rdev->mddev->pers is not NULL,
which can avoid potential NULL pointer derefence in fallowing
add_bound_rdev().

Fixes: a6da4ef85cef ("md: re-add a failed disk")
Cc: Xiao Ni <xni@redhat.com>
Cc: NeilBrown <neilb@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
---
 drivers/md/md.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 875b29ba5926..66b6bdf9f364 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2859,8 +2859,10 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
 			err = 0;
 		}
 	} else if (cmd_match(buf, "re-add")) {
-		if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1) &&
-			rdev->saved_raid_disk >= 0) {
+		if (!rdev->mddev->pers)
+			err = -EINVAL;
+		else if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1) &&
+				rdev->saved_raid_disk >= 0) {
 			/* clear_bit is performed _after_ all the devices
 			 * have their local Faulty bit cleared. If any writes
 			 * happen in the meantime in the local node, they
-- 
2.16.2.dirty

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* [PATCH v2] md: add mddev->pers to avoid potential NULL pointer dereference
@ 2019-04-02  6:22 ` Yufen Yu
  0 siblings, 0 replies; 4+ messages in thread
From: Yufen Yu @ 2019-04-02  6:22 UTC (permalink / raw)
  To: axboe, songliubraving; +Cc: neilb, xni, linux-raid, stable

When doing re-add, we need to ensure rdev->mddev->pers is not NULL,
which can avoid potential NULL pointer derefence in fallowing
add_bound_rdev().

Fixes: a6da4ef85cef ("md: re-add a failed disk")
Cc: Xiao Ni <xni@redhat.com>
Cc: NeilBrown <neilb@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
---
 drivers/md/md.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 875b29ba5926..66b6bdf9f364 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2859,8 +2859,10 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
 			err = 0;
 		}
 	} else if (cmd_match(buf, "re-add")) {
-		if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1) &&
-			rdev->saved_raid_disk >= 0) {
+		if (!rdev->mddev->pers)
+			err = -EINVAL;
+		else if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1) &&
+				rdev->saved_raid_disk >= 0) {
 			/* clear_bit is performed _after_ all the devices
 			 * have their local Faulty bit cleared. If any writes
 			 * happen in the meantime in the local node, they
-- 
2.16.2.dirty


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH v2] md: add mddev->pers to avoid potential NULL pointer dereference
  2019-04-02  6:22 ` Yufen Yu
  (?)
@ 2019-04-02 21:11 ` NeilBrown
  2019-04-02 22:41   ` Song Liu
  -1 siblings, 1 reply; 4+ messages in thread
From: NeilBrown @ 2019-04-02 21:11 UTC (permalink / raw)
  To: Yufen Yu, axboe, songliubraving; +Cc: xni, linux-raid, stable

[-- Attachment #1: Type: text/plain, Size: 1330 bytes --]

On Tue, Apr 02 2019, Yufen Yu wrote:

> When doing re-add, we need to ensure rdev->mddev->pers is not NULL,
> which can avoid potential NULL pointer derefence in fallowing
> add_bound_rdev().
>
> Fixes: a6da4ef85cef ("md: re-add a failed disk")
> Cc: Xiao Ni <xni@redhat.com>
> Cc: NeilBrown <neilb@suse.com>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Yufen Yu <yuyufen@huawei.com>

Reviewed-by: NeilBrown <neilb@suse.com>

Thanks,
NeilBrown

> ---
>  drivers/md/md.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index 875b29ba5926..66b6bdf9f364 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -2859,8 +2859,10 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
>  			err = 0;
>  		}
>  	} else if (cmd_match(buf, "re-add")) {
> -		if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1) &&
> -			rdev->saved_raid_disk >= 0) {
> +		if (!rdev->mddev->pers)
> +			err = -EINVAL;
> +		else if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1) &&
> +				rdev->saved_raid_disk >= 0) {
>  			/* clear_bit is performed _after_ all the devices
>  			 * have their local Faulty bit cleared. If any writes
>  			 * happen in the meantime in the local node, they
> -- 
> 2.16.2.dirty

[-- Attachment #2: signature.asc --]
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^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH v2] md: add mddev->pers to avoid potential NULL pointer dereference
  2019-04-02 21:11 ` NeilBrown
@ 2019-04-02 22:41   ` Song Liu
  0 siblings, 0 replies; 4+ messages in thread
From: Song Liu @ 2019-04-02 22:41 UTC (permalink / raw)
  To: NeilBrown; +Cc: Yufen Yu, axboe, xni, linux-raid, stable



> On Apr 2, 2019, at 2:11 PM, NeilBrown <neilb@suse.com> wrote:
> 
> On Tue, Apr 02 2019, Yufen Yu wrote:
> 
>> When doing re-add, we need to ensure rdev->mddev->pers is not NULL,
>> which can avoid potential NULL pointer derefence in fallowing
>> add_bound_rdev().
>> 
>> Fixes: a6da4ef85cef ("md: re-add a failed disk")
>> Cc: Xiao Ni <xni@redhat.com>
>> Cc: NeilBrown <neilb@suse.com>
>> Cc: <stable@vger.kernel.org>
>> Signed-off-by: Yufen Yu <yuyufen@huawei.com>
> 
> Reviewed-by: NeilBrown <neilb@suse.com>
> 
> Thanks,
> NeilBrown

Thanks Yufen and Neil. 

I applied it to the md-next branch:

https://github.com/liu-song-6/linux/tree/md-next

Song

> 
>> ---
>> drivers/md/md.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/md/md.c b/drivers/md/md.c
>> index 875b29ba5926..66b6bdf9f364 100644
>> --- a/drivers/md/md.c
>> +++ b/drivers/md/md.c
>> @@ -2859,8 +2859,10 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
>> 			err = 0;
>> 		}
>> 	} else if (cmd_match(buf, "re-add")) {
>> -		if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1) &&
>> -			rdev->saved_raid_disk >= 0) {
>> +		if (!rdev->mddev->pers)
>> +			err = -EINVAL;
>> +		else if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1) &&
>> +				rdev->saved_raid_disk >= 0) {
>> 			/* clear_bit is performed _after_ all the devices
>> 			 * have their local Faulty bit cleared. If any writes
>> 			 * happen in the meantime in the local node, they
>> -- 
>> 2.16.2.dirty

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-04-02 22:41 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-04-02  6:22 [PATCH v2] md: add mddev->pers to avoid potential NULL pointer dereference Yufen Yu
2019-04-02  6:22 ` Yufen Yu
2019-04-02 21:11 ` NeilBrown
2019-04-02 22:41   ` Song Liu

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