Re: [PATCH v8 19/20] pstore: fs superblock limits

[Kees Cook]

On Sun, Aug 18, 2019 at 09:58:16AM -0700, Deepa Dinamani wrote:
> Leaving granularity at 1ns because it is dependent on the specific
> attached backing pstore module. ramoops has microsecond resolution.
> 
> Fix the readback of ramoops fractional timestamp microseconds,
> which has incorrectly been reporting the value as nanoseconds since
> 3f8f80f0 ("pstore/ram: Read and write to the 'compressed' flag of pstore").

As such, this should also have:

Fixes: 3f8f80f0cfeb ("pstore/ram: Read and write to the 'compressed' flag of pstore")

> Signed-off-by: Deepa Dinamani <deepa.kernel@xxxxxxxxx>
> Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>

Also: this is going via some other tree, yes? (Or should I pick this up
for the pstore tree?)

Thanks!

-Kees

> Cc: anton@xxxxxxxxxx
> Cc: ccross@xxxxxxxxxxx
> Cc: keescook@xxxxxxxxxxxx
> Cc: tony.luck@xxxxxxxxx
> ---
>  fs/pstore/ram.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
> index 2bb3468fc93a..8caff834f002 100644
> --- a/fs/pstore/ram.c
> +++ b/fs/pstore/ram.c
> @@ -144,6 +144,7 @@ static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
>  	if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
>  		   (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
>  		   &header_length) == 3) {
> +		time->tv_nsec *= 1000;
>  		if (data_type == 'C')
>  			*compressed = true;
>  		else
> @@ -151,6 +152,7 @@ static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
>  	} else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
>  			  (time64_t *)&time->tv_sec, &time->tv_nsec,
>  			  &header_length) == 2) {
> +		time->tv_nsec *= 1000;
>  		*compressed = false;
>  	} else {
>  		time->tv_sec = 0;
> -- 
> 2.17.1
> 

-- 
Kees Cook