2021-04-29 10:48:18

by Colin King

Subject: [PATCH][next][V2] io_uring: Fix premature return from loop and memory leak

From: Colin Ian King <[email protected]>

Currently the -EINVAL error return path is leaking memory allocated
to data. Fix this by not returning immediately but instead setting
the error return variable to -EINVAL and breaking out of the loop.

Kudos to Pavel Begunkov for suggesting a correct fix.

Signed-off-by: Colin Ian King <[email protected]>
---

V2: set ret/err to -EINVAL and break rather than kfree and return,
fix both occurrences of this issue.

---
fs/io_uring.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 47c2f126f885..c783ad83f220 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8417,8 +8417,10 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
ret = io_buffer_validate(&iov);
if (ret)
break;
- if (!iov.iov_base && tag)
- return -EINVAL;
+ if (!iov.iov_base && tag) {
+ ret = -EINVAL;
+ break;
+ }

ret = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i],
&last_hpage);
@@ -8468,8 +8470,10 @@ static int __io_sqe_buffers_update(struct io_ring_ctx *ctx,
err = io_buffer_validate(&iov);
if (err)
break;
- if (!iov.iov_base && tag)
- return -EINVAL;
+ if (!iov.iov_base && tag) {
+ err = -EINVAL;
+ break;
+ }
err = io_sqe_buffer_register(ctx, &iov, &imu, &last_hpage);
if (err)
break;
--
2.30.2

2021-04-29 11:46:37

by Pavel Begunkov

Subject: Re: [PATCH][next][V2] io_uring: Fix premature return from loop and memory leak

On 4/29/21 11:46 AM, Colin King wrote:
> From: Colin Ian King <[email protected]>
>
> Currently the -EINVAL error return path is leaking memory allocated
> to data. Fix this by not returning immediately but instead setting
> the error return variable to -EINVAL and breaking out of the loop.
>
> Kudos to Pavel Begunkov for suggesting a correct fix.

Looks good, thanks
Reviewed-by: Pavel Begunkov <[email protected]>

>
> Signed-off-by: Colin Ian King <[email protected]>
> ---
>
> V2: set ret/err to -EINVAL and break rather than kfree and return,
> fix both occurrences of this issue.
>
> ---
> fs/io_uring.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index 47c2f126f885..c783ad83f220 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -8417,8 +8417,10 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
> ret = io_buffer_validate(&iov);
> if (ret)
> break;
> - if (!iov.iov_base && tag)
> - return -EINVAL;
> + if (!iov.iov_base && tag) {
> + ret = -EINVAL;
> + break;
> + }
>
> ret = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i],
> &last_hpage);
> @@ -8468,8 +8470,10 @@ static int __io_sqe_buffers_update(struct io_ring_ctx *ctx,
> err = io_buffer_validate(&iov);
> if (err)
> break;
> - if (!iov.iov_base && tag)
> - return -EINVAL;
> + if (!iov.iov_base && tag) {
> + err = -EINVAL;
> + break;
> + }
> err = io_sqe_buffer_register(ctx, &iov, &imu, &last_hpage);
> if (err)
> break;
>

--
Pavel Begunkov

2021-04-29 14:29:31

by Jens Axboe

Subject: Re: [PATCH][next][V2] io_uring: Fix premature return from loop and memory leak

On 4/29/21 4:46 AM, Colin King wrote:
> From: Colin Ian King <[email protected]>
>
> Currently the -EINVAL error return path is leaking memory allocated
> to data. Fix this by not returning immediately but instead setting
> the error return variable to -EINVAL and breaking out of the loop.
>
> Kudos to Pavel Begunkov for suggesting a correct fix.

Applied, thanks.

--
Jens Axboe