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author | Andrej Shadura <andrew.shadura@collabora.co.uk> | 2024-10-09 14:14:24 +0200 |
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committer | Luiz Augusto von Dentz <luiz.von.dentz@intel.com> | 2024-11-14 15:32:47 -0500 |
commit | 5fe6caa62b07fd39cd6a28acc8f92ba2955e11a6 (patch) | |
tree | a39d6529ee57c9291c97dd53eab7fbb31bba51dc /scripts/lib/kdoc/kdoc_parser.py | |
parent | 510e8380b0382ee3b070748656b00f83c9a5bf80 (diff) |
Bluetooth: Fix type of len in rfcomm_sock_getsockopt{,_old}()
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.
The same issue occurs in rfcomm in functions rfcomm_sock_getsockopt and
rfcomm_sock_getsockopt_old.
Change the type of len to size_t in both rfcomm_sock_getsockopt and
rfcomm_sock_getsockopt_old and replace min_t() with min().
Cc: stable@vger.kernel.org
Co-authored-by: Aleksei Vetrov <vvvvvv@google.com>
Improves: 9bf4e919ccad ("Bluetooth: Fix type of len in {l2cap,sco}_sock_getsockopt_old()")
Link: https://github.com/ClangBuiltLinux/linux/issues/2007
Link: https://github.com/llvm/llvm-project/issues/85647
Signed-off-by: Andrej Shadura <andrew.shadura@collabora.co.uk>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Diffstat (limited to 'scripts/lib/kdoc/kdoc_parser.py')
0 files changed, 0 insertions, 0 deletions