diff mbox series

[V2,2/2] ocfs2: Fix uaf in ocfs2_read_blocks

Message ID 20240820065511.996453-2-lizhi.xu@windriver.com (mailing list archive)
State New
Headers show
Series [V2,1/2] ocfs2: remove unreasonable unlock | expand

Commit Message

Lizhi Xu Aug. 20, 2024, 6:55 a.m. UTC
In the for-loop after the 'read_failure' label, the condition
'(bh == NULL) && flags includes OCFS2_BH_READAHEAD' is missing.
When this contidion is true, this for-loop will call ocfs2_set_buffer
_uptodate(ci, bh), which then triggers a NULL pointer access error.

Reported-and-suggested-by: Heming Zhao <heming.zhao@suse.com>
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
---
 fs/ocfs2/buffer_head_io.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

heming.zhao@suse.com Aug. 20, 2024, 7:15 a.m. UTC | #1
On 8/20/24 14:55, Lizhi Xu wrote:
> In the for-loop after the 'read_failure' label, the condition
> '(bh == NULL) && flags includes OCFS2_BH_READAHEAD' is missing.
> When this contidion is true, this for-loop will call ocfs2_set_buffer
> _uptodate(ci, bh), which then triggers a NULL pointer access error.
> 
> Reported-and-suggested-by: Heming Zhao <heming.zhao@suse.com>
> Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
> ---
>   fs/ocfs2/buffer_head_io.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c
> index e62c7e1de4eb..b4a76f45253d 100644
> --- a/fs/ocfs2/buffer_head_io.c
> +++ b/fs/ocfs2/buffer_head_io.c
> @@ -384,6 +384,8 @@ int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
>   					goto read_failure;
>   			}
>   		}
> +		if (!bh)
> +			continue;

If you like the style of the above two lines, put them after the
line "bh = bhs[i];", or the code below is more concise:
```
                   * completed. */
+ 		if (bh)
   			ocfs2_set_buffer_uptodate(ci, bh);
```

Thanks,
Heming
>   
>   		/* Always set the buffer in the cache, even if it was
>   		 * a forced read, or read-ahead which hasn't yet
diff mbox series

Patch

diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c
index e62c7e1de4eb..b4a76f45253d 100644
--- a/fs/ocfs2/buffer_head_io.c
+++ b/fs/ocfs2/buffer_head_io.c
@@ -384,6 +384,8 @@  int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
 					goto read_failure;
 			}
 		}
+		if (!bh)
+			continue;
 
 		/* Always set the buffer in the cache, even if it was
 		 * a forced read, or read-ahead which hasn't yet