On Fri 01-08-25 09:38:38, Thomas Weißschuh wrote:
> replace_fd() returns either a negative error number or the number of the
> new file descriptor. The current code misinterprets any positive file
> descriptor number as an error.
>
> Only check for negative error numbers, so that __receive_sock() is called
> correctly for valid file descriptors.
>
> Fixes: 173817151b15 ("fs: Expand __receive_fd() to accept existing fd")
> Fixes: 42eb0d54c08a ("fs: split receive_fd_replace from __receive_fd")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
Indeed. I'm wondering how come nobody noticed... Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> Untested, it stuck out while reading the code.
> ---
> fs/file.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/file.c b/fs/file.c
> index 6d2275c3be9c6967d16c75d1b6521f9b58980926..56c3a045121d8f43a54cf05e6ce1962f896339ac 100644
> --- a/fs/file.c
> +++ b/fs/file.c
> @@ -1387,7 +1387,7 @@ int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags)
> if (error)
> return error;
> error = replace_fd(new_fd, file, o_flags);
> - if (error)
> + if (error < 0)
> return error;
> __receive_sock(file);
> return new_fd;
>
> ---
> base-commit: 89748acdf226fd1a8775ff6fa2703f8412b286c8
> change-id: 20250801-fix-receive_fd_replace-7fdd5ce6532d
>
> Best regards,
> --
> Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
