* [PATCH] drivers:block:drbd:drbd_state:fix null-pointer dereference
@ 2017-04-25 6:35 Heloise
2017-04-25 7:06 ` Lars Ellenberg
0 siblings, 1 reply; 2+ messages in thread
From: Heloise @ 2017-04-25 6:35 UTC (permalink / raw)
To: philipp.reisner, lars.ellenberg; +Cc: drbd-dev, linux-kernel, Heloise
Signed-off-by: Heloise <os@iscas.ac.cn>
In is_valid_state(), there is NULL validation for the variable nc
"if (nc)". However,the code will continue to execute when nc is NULL.
nc->verify_alg[0] is used in subsequent code, which may cause
null-pointer dereference, fix it.
---
drivers/block/drbd/drbd_state.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index eea0c4a..1963b83 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -845,7 +845,7 @@ is_valid_state(struct drbd_device *device, union drbd_state ns)
rv = SS_CONNECTED_OUTDATES;
else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) &&
- (nc->verify_alg[0] == 0))
+ (nc != NULL && nc->verify_alg[0] == 0))
rv = SS_NO_VERIFY_ALG;
else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) &&
--
2.1.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] drivers:block:drbd:drbd_state:fix null-pointer dereference
2017-04-25 6:35 [PATCH] drivers:block:drbd:drbd_state:fix null-pointer dereference Heloise
@ 2017-04-25 7:06 ` Lars Ellenberg
0 siblings, 0 replies; 2+ messages in thread
From: Lars Ellenberg @ 2017-04-25 7:06 UTC (permalink / raw)
To: Heloise; +Cc: philipp.reisner, drbd-dev, linux-kernel
On Mon, Apr 24, 2017 at 11:35:18PM -0700, Heloise wrote:
> Signed-off-by: Heloise <os@iscas.ac.cn>
>
> In is_valid_state(), there is NULL validation for the variable nc
> "if (nc)". However,the code will continue to execute when nc is NULL.
> nc->verify_alg[0] is used in subsequent code, which may cause
> null-pointer dereference, fix it.
> ---
> drivers/block/drbd/drbd_state.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
> index eea0c4a..1963b83 100644
> --- a/drivers/block/drbd/drbd_state.c
> +++ b/drivers/block/drbd/drbd_state.c
> @@ -845,7 +845,7 @@ is_valid_state(struct drbd_device *device, union drbd_state ns)
> rv = SS_CONNECTED_OUTDATES;
>
> else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) &&
> - (nc->verify_alg[0] == 0))
> + (nc != NULL && nc->verify_alg[0] == 0))
What the static checker cannot know:
ns.conn != C_STANDALONE implies nc != NULL.
But if you feel like it, the additional check won't hurt.
Thanks,
Lars
^ permalink raw reply [flat|nested] 2+ messages in thread
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2017-04-25 6:35 [PATCH] drivers:block:drbd:drbd_state:fix null-pointer dereference Heloise
2017-04-25 7:06 ` Lars Ellenberg
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