Re: [PATCH v2] Bluetooth: Fix type of len in rfcomm_sock_getsockopt{,_old}()

[patchwork-bot+bluetooth@kernel.org]

Hello:

This patch was applied to bluetooth/bluetooth-next.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Wed,  9 Oct 2024 14:14:24 +0200 you wrote:
> Commit 9bf4e919ccad worked around an issue introduced after an innocuous
> optimisation change in LLVM main:
> 
> > len is defined as an 'int' because it is assigned from
> > '__user int *optlen'. However, it is clamped against the result of
> > sizeof(), which has a type of 'size_t' ('unsigned long' for 64-bit
> > platforms). This is done with min_t() because min() requires compatible
> > types, which results in both len and the result of sizeof() being casted
> > to 'unsigned int', meaning len changes signs and the result of sizeof()
> > is truncated. From there, len is passed to copy_to_user(), which has a
> > third parameter type of 'unsigned long', so it is widened and changes
> > signs again. This excessive casting in combination with the KCSAN
> > instrumentation causes LLVM to fail to eliminate the __bad_copy_from()
> > call, failing the build.
> 
> [...]

Here is the summary with links:
  - [v2] Bluetooth: Fix type of len in rfcomm_sock_getsockopt{,_old}()
    https://git.kernel.org/bluetooth/bluetooth-next/c/c440001ad70d

You are awesome, thank you!
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