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| author | Jakub Kicinski <kuba@kernel.org> | 2021-06-15 00:24:05 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-06-15 19:59:46 +0200 |
| commit | 475b92f932168a78da8109acd10bfb7578b8f2bb (patch) | |
| tree | 1659ca2f045d8cc6295dae645c844e3228326494 /CREDITS | |
| parent | net: mhi_net: Update the transmit handler prototype (diff) | |
| download | linux-475b92f932168a78da8109acd10bfb7578b8f2bb.tar.xz linux-475b92f932168a78da8109acd10bfb7578b8f2bb.zip | |
ptp: improve max_adj check against unreasonable values
Scaled PPM conversion to PPB may (on 64bit systems) result
in a value larger than s32 can hold (freq/scaled_ppm is a long).
This means the kernel will not correctly reject unreasonably
high ->freq values (e.g. > 4294967295ppb, 281474976645 scaled PPM).
The conversion is equivalent to a division by ~66 (65.536),
so the value of ppb is always smaller than ppm, but not small
enough to assume narrowing the type from long -> s32 is okay.
Note that reasonable user space (e.g. ptp4l) will not use such
high values, anyway, 4289046510ppb ~= 4.3x, so the fix is
somewhat pedantic.
Fixes: d39a743511cd ("ptp: validate the requested frequency adjustment.")
Fixes: d94ba80ebbea ("ptp: Added a brand new class driver for ptp clocks.")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
0 files changed, 0 insertions, 0 deletions