Re: [ptxdist] Bug in BusyBox 1.37.0 - NTPD Module

[Roland Hieber <rhi@pengutronix.de>]

Hi,

On Fri, Jan 31, 2025 at 01:06:05PM +0100, ruggero rossi wrote:
> HHello everyone,
> 
> My BSP still uses an older version of Linux and libc with a 32-bit time_t.
> 
> While migrating to ptxdist-2025.01.0, I encountered an unexpected crash in
> the ntpd service. Specifically, when the BSP acts as an ntpd server, the
> crash occurs on the client side.
> 
> After investigating the issue, I believe I have identified a bug. On my
> system, time_t is effectively an int32_t. In the function that converts a
> double to the NTP time format, I found the following code:
> 
> double d;
> uint32_t intl;
> intl = (uint32_t)(time_t)d;
> 
> Here, the integer part of d represents the number of seconds since
> 1900-01-01T00:00:00.0, which exceeds 31 bits.
> 
> Casting d to time_t in the server truncates the value to 0x7fffffff,
> leading to a crash in the client.
> 
> The solution is to avoid the cast to time_t when sizeof(time_t) == 4.
> 
> I have attached a proposed patch for this issue. If someone with more
> authority in the project could report this upstream, that would be
> appreciated.

I don't see any patches in PTXdist that could interfere, so I think it's an
upstream issue. The code in question was refactored in 2023:
<https://git.busybox.net/busybox/commit/?id=85acf71d2579ebe4eec05c6f31901ad>

I think now that you debugged this issue, you now have the most knowledge about
it of all of us here … :) So I would suggest that you send the same message to
the busybox list: https://www.busybox.net/lists.html
Getting the issue solved upstream is the most ideal solution for all users of
busybox, and PTXdist will pick it up when a fix is released in busybox.

What is with the other 5 patches you sent? Are these somehow related?

0002-meson-dont-build-blkzone-if-blkzoned.h-is-not-available.patch
0003-meson-dont-build-blkpr-if-pr.h-is-not-available.patch
0004-meson-dont-build-lsfd-if-kcmp.h-is-not-available.patch
0005-meson-dont-build-mkfds-if-SIOCGSKNS-is-not-available.patch
util-linux.make.patch

 - Roland

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