Messages in this thread | | | Date | Thu, 10 Aug 2023 23:16:05 -0700 | Subject | Re: [PATCH] printk: ringbuffer: Fix truncating buffer size min_t cast | From | Vijay Balakrishna <> |
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On 8/10/23 22:45, Kees Cook wrote: > If an output buffer size exceeded U16_MAX, the min_t(u16, ...) cast in > copy_data() was causing writes to truncate. This manifested as output > bytes being skipped, seen as %NUL bytes in pstore dumps when the available > record size was larger than 65536. Fix the cast to no longer truncate > the calculation. > > Cc: Petr Mladek <pmladek@suse.com> > Cc: Sergey Senozhatsky <senozhatsky@chromium.org> > Cc: Steven Rostedt <rostedt@goodmis.org> > Cc: John Ogness <john.ogness@linutronix.de> > Reported-by: Vijay Balakrishna <vijayb@linux.microsoft.com> > Closes: https://lore.kernel.org/lkml/d8bb1ec7-a4c5-43a2-9de0-9643a70b899f@linux.microsoft.com/ > Fixes: b6cf8b3f3312 ("printk: add lockless ringbuffer") > Cc: stable@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org>
Excellent.
I have verified on v5.10.
Tested-by: Vijay Balakrishna <vijayb@linux.microsoft.com>
Thanks, Vijay
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