On Thu 2023-08-10 22:45:32, 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@xxxxxxxx> > Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> > Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> > Cc: John Ogness <john.ogness@xxxxxxxxxxxxx> > Reported-by: Vijay Balakrishna <vijayb@xxxxxxxxxxxxxxxxxxx> > Closes: https://lore.kernel.org/lkml/d8bb1ec7-a4c5-43a2-9de0-9643a70b899f@xxxxxxxxxxxxxxxxxxx/ checkpatch.pl suggested that "Link:" should be used instead of "Closes:". > Fixes: b6cf8b3f3312 ("printk: add lockless ringbuffer") > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Reviewed-by: Petr Mladek <pmladek@xxxxxxxx> Thanks a lot for tracking this down. The patch has been comitted into printk/linux.git, branch for-6.6. I though about pushing it for 5.5-rc7. But it is pretty old issue. It does not break the system. I wanted to give it some spin in linux-next. And I leave for vacation on Thursday. I will not have internet connection until Aug 28. Best Regards, Petr
