Messages in this thread | | | Date | Fri, 19 Apr 2019 10:51:12 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [PATCH v7 00/10] vsprintf: Prevent silent crashes and consolidate error handling |
| |
On (04/17/19 13:53), Petr Mladek wrote: > Crash in vsprintf() might be silent when it happens under logbuf_lock > in vprintk_emit(). This patch set prevents most of the crashes by probing > the address. The check is done only by %s and some %p* specifiers that need > to dereference the address. > > Only the first byte of the address is checked to keep it simple. It should > be enough to catch most problems. > > The check is explicitly done in each function that does the dereference. > It helps to avoid the questionable strchr() of affected specifiers. This > change motivated me to do some preparation patches that consolidated > the error handling and cleaned the code a bit.
The patch set looks OK to me.
I got confused by 'pC?' error string, but once you start looking at it as a regex (? - zero or one occurrences) things look OK. Regex in dmesg/serial output might be something very new to people, stack traces, after all, is a rather common error reporting mechanism. So the previous "WARN_ON() + exact unrecognized fmt[N] char" was not totally awful or wrong (well, it was, before we introduced printk_safe()), but I don't have strong objections against that new regex thing.
FWIW, Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
-ss
| |