Ensure correct alignment when dealing with control messages #662
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refi64
reviewed
Oct 17, 2024
As documented in cmsg(3), the alignment of control messages is not guaranteed, so for portability to architectures with strong alignment requirements we should memcpy to and from a suitably aligned instance of the desired data structure on the stack. Helps: containers#637 Signed-off-by: Simon McVittie <smcv@collabora.com>
A char array on the stack is not guaranteed to have any particular alignment. Resolves: containers#637 Signed-off-by: Simon McVittie <smcv@collabora.com>
refi64
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Oct 17, 2024
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utils: Don't assume cmsg data is aligned suitably for struct ucred
As documented in cmsg(3), the alignment of control messages is not
guaranteed, so for portability to architectures with strong alignment
requirements we should memcpy to and from a suitably aligned instance
of the desired data structure on the stack.
Helps: bubblewrap misuses CMSG_DATA() macro #637
utils: Ensure that the buffer for struct cmsghdr is suitably-aligned
A char array on the stack is not guaranteed to have any particular
alignment.
Resolves: bubblewrap misuses CMSG_DATA() macro #637
cc @mcatanzaro @refi64