Re: [PATCH v2 1/2] printk: Fix panic caused by passing log_buf_len to command line

[Sergey Senozhatsky]

On (09/19/18 10:27), He Zhe wrote:
> On 2018å09æ19æ 09:50, Sergey Senozhatsky wrote:
> > On (09/19/18 01:17), zhe.he@xxxxxxxxxxxxx wrote:
> >> @@ -1048,7 +1048,14 @@ static void __init log_buf_len_update(unsigned size)
> >>  /* save requested log_buf_len since it's too early to process it */
> >>  static int __init log_buf_len_setup(char *str)
> >>  {
> >> -	unsigned size = memparse(str, &str);
> >> +	unsigned size;
> > 	unsigned int size;
> 
> This is in v1 but then Steven suggested that it should be split out
> and only keep the pure fix part here.

Ah, I see.

Hmm... memparse() returns u64 value. A user *probably* can ask the kernel
to allocate log_buf larger than 'unsigned int'.

So may be I'd do two fixes here:

 First  - switch to u64 size.
 Second - check for NULL str.


Steven, Petr, what do you think?

	-ss