On Thursday 30 October 2014 10:23:31 Xiong Zhou wrote:
> From: Xiong Zhou <jencce.ker...@gmail.com>
>
> struct logger_entry can be returned to userspace via ioctl,
> so it is wrong to have a kuid_t member, fixing it to uid_t.
> This was introduced by commit bd471258f2, to pass uidguid
> type checks : UIDGID_STRICT_TYPE_CHECKS, which has been
> removed from kernel in commit 261000a56b6.
>
> Fixes: bd471258f2 (logger: use kuid_t instead of uid_t)
> Signed-off-by: Xiong Zhou <jencce.ker...@gmail.com>
Sorry, but this isn't good.
You had an earlier patch that introduced a bug by hiding a warning,
and now you send a new patch to hide the bug better instead of
fixing it?
> diff --git a/drivers/staging/android/logger.c
> b/drivers/staging/android/logger.c
> index 28b93d3..fb06bf2 100644
> --- a/drivers/staging/android/logger.c
> +++ b/drivers/staging/android/logger.c
> @@ -252,7 +252,7 @@ static size_t get_next_entry_by_uid(struct logger_log
> *log,
>
> entry = get_entry_header(log, off, &scratch);
>
> - if (uid_eq(entry->euid, euid))
> + if (entry->euid == __kuid_val(euid))
> return off;
>
> next_len = sizeof(struct logger_entry) + entry->len;
The code above was correct, you are just breaking it more.
> @@ -430,7 +430,7 @@ static ssize_t logger_write_iter(struct kiocb *iocb,
> struct iov_iter *from)
> header.tid = current->pid;
> header.sec = now.tv_sec;
> header.nsec = now.tv_nsec;
> - header.euid = current_euid();
> + header.euid = __kuid_val(current_euid());
> header.len = count;
> header.hdr_size = sizeof(struct logger_entry);
>
This writes to the internal data structure, so here you should still use
kuid_t. The problem is that you are later leaking this to user space,
so a user in one container can read entries from a user with the same
uid in another container, and that a process calling read() with the
r_all bit set will get entries with uids from all containers, using
the kernel-internal uid values instead of the ones valid for the current
container.
Arnd
_______________________________________________
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
