2022-07-21 11:32:43

by Dylan Yudaken

Subject: [PATCH] io_uring: fix free of unallocated buffer list

in the error path of io_register_pbuf_ring, only free bl if it was
allocated.

Reported-by: Dipanjan Das <[email protected]>
Fixes: c7fb19428d67 ("io_uring: add support for ring mapped supplied buffers")
Signed-off-by: Dylan Yudaken <[email protected]>
---
fs/io_uring.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index a01ea49f3017..2b7bb62c7805 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -12931,7 +12931,7 @@ static int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
{
struct io_uring_buf_ring *br;
struct io_uring_buf_reg reg;
- struct io_buffer_list *bl;
+ struct io_buffer_list *bl, *free_bl = NULL;
struct page **pages;
int nr_pages;

@@ -12963,7 +12963,7 @@ static int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
if (bl->buf_nr_pages || !list_empty(&bl->buf_list))
return -EEXIST;
} else {
- bl = kzalloc(sizeof(*bl), GFP_KERNEL);
+ free_bl = bl = kzalloc(sizeof(*bl), GFP_KERNEL);
if (!bl)
return -ENOMEM;
}
@@ -12972,7 +12972,7 @@ static int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
struct_size(br, bufs, reg.ring_entries),
&nr_pages);
if (IS_ERR(pages)) {
- kfree(bl);
+ kfree(free_bl);
return PTR_ERR(pages);
}


base-commit: ff6992735ade75aae3e35d16b17da1008d753d28
--
2.30.2

2022-07-21 11:37:16

by Pavel Begunkov

Subject: Re: [PATCH] io_uring: fix free of unallocated buffer list

On 7/21/22 12:01, Dylan Yudaken wrote:
> in the error path of io_register_pbuf_ring, only free bl if it was
> allocated.

Reviewed-by: Pavel Begunkov <[email protected]>


> Reported-by: Dipanjan Das <[email protected]>
> Fixes: c7fb19428d67 ("io_uring: add support for ring mapped supplied buffers")
> Signed-off-by: Dylan Yudaken <[email protected]>
> ---
> fs/io_uring.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index a01ea49f3017..2b7bb62c7805 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -12931,7 +12931,7 @@ static int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
> {
> struct io_uring_buf_ring *br;
> struct io_uring_buf_reg reg;
> - struct io_buffer_list *bl;
> + struct io_buffer_list *bl, *free_bl = NULL;
> struct page **pages;
> int nr_pages;
>
> @@ -12963,7 +12963,7 @@ static int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
> if (bl->buf_nr_pages || !list_empty(&bl->buf_list))
> return -EEXIST;
> } else {
> - bl = kzalloc(sizeof(*bl), GFP_KERNEL);
> + free_bl = bl = kzalloc(sizeof(*bl), GFP_KERNEL);
> if (!bl)
> return -ENOMEM;
> }
> @@ -12972,7 +12972,7 @@ static int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
> struct_size(br, bufs, reg.ring_entries),
> &nr_pages);
> if (IS_ERR(pages)) {
> - kfree(bl);
> + kfree(free_bl);
> return PTR_ERR(pages);
> }
>
>
> base-commit: ff6992735ade75aae3e35d16b17da1008d753d28

--
Pavel Begunkov

2022-07-21 14:44:11

by Jens Axboe

Subject: Re: [PATCH] io_uring: fix free of unallocated buffer list

On Thu, 21 Jul 2022 04:01:15 -0700, Dylan Yudaken wrote:
> in the error path of io_register_pbuf_ring, only free bl if it was
> allocated.
>
>

Applied, thanks!

[1/1] io_uring: fix free of unallocated buffer list
commit: ec8516f3b7c40ba7050e6b3a32467e9de451ecdf

Best regards,
--
Jens Axboe