* [PATCH] io_uring: Fix NULL dereference in error in io_sqe_files_register()
@ 2021-02-01 12:23 Dan Carpenter
2021-02-01 18:34 ` Pavel Begunkov
2021-02-01 18:57 ` Jens Axboe
0 siblings, 2 replies; 3+ messages in thread
From: Dan Carpenter @ 2021-02-01 12:23 UTC (permalink / raw)
To: Jens Axboe, Bijan Mottahedeh; +Cc: Pavel Begunkov, io-uring, kernel-janitors
If we hit a "goto out_free;" before the "ctx->file_data" pointer has
been assigned then it leads to a NULL derefence when we call:
free_fixed_rsrc_data(ctx->file_data);
We can fix this by moving the assignment earlier.
Fixes: 3cfb739c561e ("io_uring: create common fixed_rsrc_data allocation routines")
Signed-off-by: Dan Carpenter <[email protected]>
---
fs/io_uring.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 03748faa5295..8e8b74dd7d9b 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7869,6 +7869,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
file_data = alloc_fixed_rsrc_data(ctx);
if (!file_data)
return -ENOMEM;
+ ctx->file_data = file_data;
nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE);
file_data->table = kcalloc(nr_tables, sizeof(*file_data->table),
@@ -7878,7 +7879,6 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
if (io_sqe_alloc_file_tables(file_data, nr_tables, nr_args))
goto out_free;
- ctx->file_data = file_data;
for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
struct fixed_rsrc_table *table;
--
2.29.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] io_uring: Fix NULL dereference in error in io_sqe_files_register()
2021-02-01 12:23 [PATCH] io_uring: Fix NULL dereference in error in io_sqe_files_register() Dan Carpenter
@ 2021-02-01 18:34 ` Pavel Begunkov
2021-02-01 18:57 ` Jens Axboe
1 sibling, 0 replies; 3+ messages in thread
From: Pavel Begunkov @ 2021-02-01 18:34 UTC (permalink / raw)
To: Dan Carpenter, Jens Axboe, Bijan Mottahedeh; +Cc: io-uring, kernel-janitors
On 01/02/2021 12:23, Dan Carpenter wrote:
> If we hit a "goto out_free;" before the "ctx->file_data" pointer has
> been assigned then it leads to a NULL derefence when we call:
>
> free_fixed_rsrc_data(ctx->file_data);
>
> We can fix this by moving the assignment earlier.
looks good, thanks
Reviewed-by: Pavel Begunkov <[email protected]>
>
> Fixes: 3cfb739c561e ("io_uring: create common fixed_rsrc_data allocation routines")
> Signed-off-by: Dan Carpenter <[email protected]>
> ---
> fs/io_uring.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index 03748faa5295..8e8b74dd7d9b 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -7869,6 +7869,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
> file_data = alloc_fixed_rsrc_data(ctx);
> if (!file_data)
> return -ENOMEM;
> + ctx->file_data = file_data;
>
> nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE);
> file_data->table = kcalloc(nr_tables, sizeof(*file_data->table),
> @@ -7878,7 +7879,6 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
>
> if (io_sqe_alloc_file_tables(file_data, nr_tables, nr_args))
> goto out_free;
> - ctx->file_data = file_data;
>
> for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
> struct fixed_rsrc_table *table;
>
--
Pavel Begunkov
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] io_uring: Fix NULL dereference in error in io_sqe_files_register()
2021-02-01 12:23 [PATCH] io_uring: Fix NULL dereference in error in io_sqe_files_register() Dan Carpenter
2021-02-01 18:34 ` Pavel Begunkov
@ 2021-02-01 18:57 ` Jens Axboe
1 sibling, 0 replies; 3+ messages in thread
From: Jens Axboe @ 2021-02-01 18:57 UTC (permalink / raw)
To: Dan Carpenter, Bijan Mottahedeh; +Cc: Pavel Begunkov, io-uring, kernel-janitors
On 2/1/21 5:23 AM, Dan Carpenter wrote:
> If we hit a "goto out_free;" before the "ctx->file_data" pointer has
> been assigned then it leads to a NULL derefence when we call:
>
> free_fixed_rsrc_data(ctx->file_data);
>
> We can fix this by moving the assignment earlier.
Applied, thanks Dan.
--
Jens Axboe
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-02-01 12:23 [PATCH] io_uring: Fix NULL dereference in error in io_sqe_files_register() Dan Carpenter
2021-02-01 18:34 ` Pavel Begunkov
2021-02-01 18:57 ` Jens Axboe
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