diff mbox series

[v1] exfat: fix unexpected EOF while reading dir

Message ID PUZPR04MB6316182889B5CE8003A5324981EC9@PUZPR04MB6316.apcprd04.prod.outlook.com
State New
Headers
Series [v1] exfat: fix unexpected EOF while reading dir |

Commit Message

Yuezhang.Mo@sony.com Dec. 26, 2022, 7:23 a.m. UTC 
  If the position is not aligned with the dentry size, the return
value of readdir() will be NULL and errno is 0, which means the
end of the directory stream is reached.

If the position is aligned with dentry size, but there is no file
or directory at the position, exfat_readdir() will continue to
get dentry from the next dentry. So the dentry gotten by readdir()
may not be at the position.

After this commit, if the position is not aligned with the dentry
size, round the position up to the dentry size and continue to get
the dentry.

Fixes: ca06197382bd ("exfat: add directory operations")

Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reported-by: Wang Yugui <wangyugui@e16-tech.com>
---
 fs/exfat/dir.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

-- 
2.25.1

Comments

Sungjong Seo Dec. 29, 2022, 2:25 a.m. UTC | #1 
> If the position is not aligned with the dentry size, the return
> value of readdir() will be NULL and errno is 0, which means the
> end of the directory stream is reached.
> 
> If the position is aligned with dentry size, but there is no file
> or directory at the position, exfat_readdir() will continue to
> get dentry from the next dentry. So the dentry gotten by readdir()
> may not be at the position.
> 
> After this commit, if the position is not aligned with the dentry
> size, round the position up to the dentry size and continue to get
> the dentry.
> 
> Fixes: ca06197382bd ("exfat: add directory operations")
> 
> Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
> Reviewed-by: Andy Wu <Andy.Wu@sony.com>
> Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
> Reported-by: Wang Yugui <wangyugui@e16-tech.com>

Looks good. Thanks.

Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>

> ---
>  fs/exfat/dir.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
> index 1dfa67f307f1..1122bee3b634 100644
> --- a/fs/exfat/dir.c
> +++ b/fs/exfat/dir.c
> @@ -234,10 +234,7 @@ static int exfat_iterate(struct file *file, struct
> dir_context *ctx)
>  		fake_offset = 1;
>  	}
> 
> -	if (cpos & (DENTRY_SIZE - 1)) {
> -		err = -ENOENT;
> -		goto unlock;
> -	}
> +	cpos = round_up(cpos, DENTRY_SIZE);
> 
>  	/* name buffer should be allocated before use */
>  	err = exfat_alloc_namebuf(nb);
> --
> 2.25.1
Namjae Jeon Dec. 30, 2022, 1:33 a.m. UTC | #2 
2022-12-26 16:23 GMT+09:00, Yuezhang.Mo@sony.com <Yuezhang.Mo@sony.com>:
> If the position is not aligned with the dentry size, the return
> value of readdir() will be NULL and errno is 0, which means the
> end of the directory stream is reached.
>
> If the position is aligned with dentry size, but there is no file
> or directory at the position, exfat_readdir() will continue to
> get dentry from the next dentry. So the dentry gotten by readdir()
> may not be at the position.
>
> After this commit, if the position is not aligned with the dentry
> size, round the position up to the dentry size and continue to get
> the dentry.
>
> Fixes: ca06197382bd ("exfat: add directory operations")
>
> Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
> Reviewed-by: Andy Wu <Andy.Wu@sony.com>
> Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
> Reported-by: Wang Yugui <wangyugui@e16-tech.com>
Applied, Thanks for your patch!
diff mbox series

Patch

diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index 1dfa67f307f1..1122bee3b634 100644
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -234,10 +234,7 @@  static int exfat_iterate(struct file *file, struct dir_context *ctx)
 		fake_offset = 1;
 	}
 
-	if (cpos & (DENTRY_SIZE - 1)) {
-		err = -ENOENT;
-		goto unlock;
-	}
+	cpos = round_up(cpos, DENTRY_SIZE);
 
 	/* name buffer should be allocated before use */
 	err = exfat_alloc_namebuf(nb);