* [PATCH V4] rxe: Fix a sleep-in-atomic bug in post_one_send
@ 2017-06-05 9:39 ` Jia-Ju Bai
0 siblings, 0 replies; 4+ messages in thread
From: Jia-Ju Bai @ 2017-06-05 9:39 UTC (permalink / raw)
To: monis-VPRAkNaXOzVWk0Htik3J/w, sean.hefty-ral2JQCrhuEAvxtiuMwx3w,
dledford-H+wXaHxf7aLQT0dZR+AlfA,
hal.rosenstock-Re5JQEeQqe8AvxtiuMwx3w,
yuval.shaia-QHcLZuEGTsvQT0dZR+AlfA
Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA, Jia-Ju Bai
The driver may sleep under a spin lock, and the function call path is:
post_one_send (acquire the lock by spin_lock_irqsave)
init_send_wqe
copy_from_user --> may sleep
There is no flow that makes "qp->is_user" true, and copy_from_user may
cause bug when a non-user pointer is used. So, the line of copy_from_user
is removed.
Signed-off-by: Jia-Ju Bai <baijiaju1990-9Onoh4P/yGk@public.gmane.org>
---
V4:
* Remove the line of copy_from_user.
V3:
* It corrects the mistakes of remaining legacy code in V2.
(Thank Ram for pointing it out)
V2:
* The parameter "flags" is added to restore and save the irq status.
Thank Leon for good advice.
---
drivers/infiniband/sw/rxe/rxe_verbs.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
index 83d709e..7c52c7c 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -740,11 +740,7 @@ static int init_send_wqe(struct rxe_qp *qp, struct ib_send_wr *ibwr,
sge = ibwr->sg_list;
for (i = 0; i < num_sge; i++, sge++) {
- if (qp->is_user && copy_from_user(p, (__user void *)
- (uintptr_t)sge->addr, sge->length))
- return -EFAULT;
-
- else if (!qp->is_user)
+ if (!qp->is_user)
memcpy(p, (void *)(uintptr_t)sge->addr,
sge->length);
--
1.7.9.5
--
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^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH V4] rxe: Fix a sleep-in-atomic bug in post_one_send
@ 2017-06-05 9:39 ` Jia-Ju Bai
0 siblings, 0 replies; 4+ messages in thread
From: Jia-Ju Bai @ 2017-06-05 9:39 UTC (permalink / raw)
To: monis, sean.hefty, dledford, hal.rosenstock, yuval.shaia
Cc: linux-rdma, linux-kernel, Jia-Ju Bai
The driver may sleep under a spin lock, and the function call path is:
post_one_send (acquire the lock by spin_lock_irqsave)
init_send_wqe
copy_from_user --> may sleep
There is no flow that makes "qp->is_user" true, and copy_from_user may
cause bug when a non-user pointer is used. So, the line of copy_from_user
is removed.
Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
---
V4:
* Remove the line of copy_from_user.
V3:
* It corrects the mistakes of remaining legacy code in V2.
(Thank Ram for pointing it out)
V2:
* The parameter "flags" is added to restore and save the irq status.
Thank Leon for good advice.
---
drivers/infiniband/sw/rxe/rxe_verbs.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
index 83d709e..7c52c7c 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -740,11 +740,7 @@ static int init_send_wqe(struct rxe_qp *qp, struct ib_send_wr *ibwr,
sge = ibwr->sg_list;
for (i = 0; i < num_sge; i++, sge++) {
- if (qp->is_user && copy_from_user(p, (__user void *)
- (uintptr_t)sge->addr, sge->length))
- return -EFAULT;
-
- else if (!qp->is_user)
+ if (!qp->is_user)
memcpy(p, (void *)(uintptr_t)sge->addr,
sge->length);
--
1.7.9.5
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH V4] rxe: Fix a sleep-in-atomic bug in post_one_send
2017-06-05 9:39 ` Jia-Ju Bai
@ 2017-06-05 10:12 ` Leon Romanovsky
-1 siblings, 0 replies; 4+ messages in thread
From: Leon Romanovsky @ 2017-06-05 10:12 UTC (permalink / raw)
To: Jia-Ju Bai
Cc: monis-VPRAkNaXOzVWk0Htik3J/w, sean.hefty-ral2JQCrhuEAvxtiuMwx3w,
dledford-H+wXaHxf7aLQT0dZR+AlfA,
hal.rosenstock-Re5JQEeQqe8AvxtiuMwx3w,
yuval.shaia-QHcLZuEGTsvQT0dZR+AlfA,
linux-rdma-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA
[-- Attachment #1: Type: text/plain, Size: 1827 bytes --]
On Mon, Jun 05, 2017 at 05:39:48PM +0800, Jia-Ju Bai wrote:
> The driver may sleep under a spin lock, and the function call path is:
> post_one_send (acquire the lock by spin_lock_irqsave)
> init_send_wqe
> copy_from_user --> may sleep
>
> There is no flow that makes "qp->is_user" true, and copy_from_user may
> cause bug when a non-user pointer is used. So, the line of copy_from_user
> is removed.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990-9Onoh4P/yGk@public.gmane.org>
> ---
> V4:
> * Remove the line of copy_from_user.
>
> V3:
> * It corrects the mistakes of remaining legacy code in V2.
> (Thank Ram for pointing it out)
>
> V2:
> * The parameter "flags" is added to restore and save the irq status.
> Thank Leon for good advice.
> ---
> drivers/infiniband/sw/rxe/rxe_verbs.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
> index 83d709e..7c52c7c 100644
> --- a/drivers/infiniband/sw/rxe/rxe_verbs.c
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
> @@ -740,11 +740,7 @@ static int init_send_wqe(struct rxe_qp *qp, struct ib_send_wr *ibwr,
>
> sge = ibwr->sg_list;
> for (i = 0; i < num_sge; i++, sge++) {
> - if (qp->is_user && copy_from_user(p, (__user void *)
> - (uintptr_t)sge->addr, sge->length))
> - return -EFAULT;
> -
> - else if (!qp->is_user)
> + if (!qp->is_user)
According to the Moni's previous responses the line above is always true.
> memcpy(p, (void *)(uintptr_t)sge->addr,
> sge->length);
>
> --
> 1.7.9.5
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH V4] rxe: Fix a sleep-in-atomic bug in post_one_send
@ 2017-06-05 10:12 ` Leon Romanovsky
0 siblings, 0 replies; 4+ messages in thread
From: Leon Romanovsky @ 2017-06-05 10:12 UTC (permalink / raw)
To: Jia-Ju Bai
Cc: monis, sean.hefty, dledford, hal.rosenstock, yuval.shaia,
linux-rdma, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 1782 bytes --]
On Mon, Jun 05, 2017 at 05:39:48PM +0800, Jia-Ju Bai wrote:
> The driver may sleep under a spin lock, and the function call path is:
> post_one_send (acquire the lock by spin_lock_irqsave)
> init_send_wqe
> copy_from_user --> may sleep
>
> There is no flow that makes "qp->is_user" true, and copy_from_user may
> cause bug when a non-user pointer is used. So, the line of copy_from_user
> is removed.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
> ---
> V4:
> * Remove the line of copy_from_user.
>
> V3:
> * It corrects the mistakes of remaining legacy code in V2.
> (Thank Ram for pointing it out)
>
> V2:
> * The parameter "flags" is added to restore and save the irq status.
> Thank Leon for good advice.
> ---
> drivers/infiniband/sw/rxe/rxe_verbs.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
> index 83d709e..7c52c7c 100644
> --- a/drivers/infiniband/sw/rxe/rxe_verbs.c
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
> @@ -740,11 +740,7 @@ static int init_send_wqe(struct rxe_qp *qp, struct ib_send_wr *ibwr,
>
> sge = ibwr->sg_list;
> for (i = 0; i < num_sge; i++, sge++) {
> - if (qp->is_user && copy_from_user(p, (__user void *)
> - (uintptr_t)sge->addr, sge->length))
> - return -EFAULT;
> -
> - else if (!qp->is_user)
> + if (!qp->is_user)
According to the Moni's previous responses the line above is always true.
> memcpy(p, (void *)(uintptr_t)sge->addr,
> sge->length);
>
> --
> 1.7.9.5
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
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^ permalink raw reply [flat|nested] 4+ messages in thread
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Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2017-06-05 9:39 [PATCH V4] rxe: Fix a sleep-in-atomic bug in post_one_send Jia-Ju Bai
2017-06-05 9:39 ` Jia-Ju Bai
[not found] ` <1496655588-5598-1-git-send-email-baijiaju1990-9Onoh4P/yGk@public.gmane.org>
2017-06-05 10:12 ` Leon Romanovsky
2017-06-05 10:12 ` Leon Romanovsky
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