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getgroups() is not guaranteed to return the same number of groups between calls. Because groups are a flat namespace and group numbers might collide if the system is subscribing to different directories, some systems deduplicate groups with the same GID. The first call should be used to retrieve the high watermark needed to allocate the buffer, the second one should be used to retrieve the group numbers as well as the actual number of groups we have been given. Under certain circumstances, the current code causes sudo to read uninitialized content present in the buffer.
millert
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…tic. On systems where getgroups() returns results based on more than just the per-process group vector in the kernel it is possible for the number of groups to change in between invocations. Based on GitHub PR #106 from Pierre-Olivier Martel.
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Thanks, I committed a slightly different diff that doesn't introduce a new variable in 7a309d7 |
millert
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Jul 27, 2021
…tic. On systems where getgroups() returns results based on more than just the per-process group vector in the kernel it is possible for the number of groups to change in between invocations. Based on GitHub PR #106 from Pierre-Olivier Martel. --HG-- branch : 1.9
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getgroups() is not guaranteed to return the same number of groups
between calls. Because groups are a flat namespace and group numbers
might collide if the system is subscribing to different directories,
some systems deduplicate groups with the same GID. The first call
should be used to retrieve the high watermark needed to allocate
the buffer, the second one should be used to retrieve the group
numbers as well as the actual number of groups we have been given.
Under certain circumstances, the current code causes sudo to read
uninitialized content present in the buffer.