Messages in this thread | | | Subject | Re: [PATCH] time: Validate the usec before covert to nsec in do_adjtimex | From | "zhangxiaoxu (A)" <> | Date | Mon, 8 Jul 2019 18:42:13 +0800 |
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在 2019/7/8 17:24, Thomas Gleixner 写道: > On Mon, 8 Jul 2019, ZhangXiaoxu wrote: > >> When covert the usec to nsec, it will multiple 1000, it maybe >> overflow and lead an undefined behavior. >> >> For example, users may input an negative tv_usec values when >> call adjtimex syscall, then multiple 1000 maybe overflow it >> to a positive and legal number. >> >> So, we should validate the usec before coverted it to nsec. > > That's correct, but the actuall inject function wants to keep the sanity > check, timekeeping_inject_offset is called only by timekeeping_warp_clock and do_adjtimex. The do_adjtimex already validate it, and timekeeping_warp_clock is set tv_nsec=0. We keep the sanity check is for some other maybe use this function? I had send a v2 to keep the sanity check in timekeeping_inject_offset.
Thanks. > > Thanks, > > tglx > > . >
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