elf: resolve paths in ldd() to purge relative path components
#2932
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Still debugging this error. For some reason there appears to be an empty string lib getting returned in the crystal case, which expands to the cwd by abspath. |
ldd may return paths with relative components such as "..", e.g.:
{
'linux-vdso.so.1': '',
'libc.so.6': '/snap/core/current/lib/x86_64-linux-gnu/libc.so.6',
'libnvidia-container.so.1': '/root/prime/usr/bin/../lib/x86_64-linux-gnu/libnvidia-container.so.1',
'libcap.so.2': '/snap/core/current/lib/x86_64-linux-gnu/libcap.so.2',
'libdl.so.2': '/snap/core/current/lib/x86_64-linux-gnu/libdl.so.2',
'libseccomp.so.2': '/snap/core/current/lib/x86_64-linux-gnu/libseccomp.so.2'
}
(1) Resolve the paths before using them to ensure we have a consistent
values that do not look odd in potential warnings/errors (e.g.
corrupted ELF).
This also appears to expose an issue with the FakeElf fixture which
was not creating a fake "barsnap.so.2" in the core base path. This
updates the fixture to create one in the same manner as it does for
the root libraries.
(2) In the same example above, we can see linux-vdso has an empty string.
In Ubuntu 16.04, ldd will return a slightly different formatted string
which results in an empty path for the "found" shared object path. I do
not believe it has caused a problem before attempting to use abspath
on it.
Check for the empty-string case and ignore it. We don't need to check
linux-vdso, and calling abspath on it will resolve to the current
working directory.
(3) Add some unit tests for validating ldd parsing.
Signed-off-by: Chris Patterson <chris.patterson@canonical.com>
sergiusens
requested changes
Feb 14, 2020
Will do, sorry about that. I hadn't thought you reviewed it yet. |
|
I just did not assess, but I have been looking at this since it first came out :-) |
sergiusens
reviewed
Feb 14, 2020
added 2 commits
February 14, 2020 11:21
Signed-off-by: Chris Patterson <chris.patterson@canonical.com>
Signed-off-by: Chris Patterson <chris.patterson@canonical.com>
sergiusens
approved these changes
Feb 15, 2020
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elf: resolve paths in
ldd()to purge relative path componentsldd may return paths with relative components such as "..", e.g.:
{
'linux-vdso.so.1': '',
'libc.so.6': '/snap/core/current/lib/x86_64-linux-gnu/libc.so.6',
'libnvidia-container.so.1': '/root/prime/usr/bin/../lib/x86_64-linux-gnu/libnvidia-container.so.1',
'libcap.so.2': '/snap/core/current/lib/x86_64-linux-gnu/libcap.so.2',
'libdl.so.2': '/snap/core/current/lib/x86_64-linux-gnu/libdl.so.2',
'libseccomp.so.2': '/snap/core/current/lib/x86_64-linux-gnu/libseccomp.so.2'
}
(1) Resolve the paths before using them to ensure we have a consistent
values that do not look odd in potential warnings/errors (e.g.
corrupted ELF).
This also appears to expose an issue with the FakeElf fixture which
was not creating a fake "barsnap.so.2" in the core base path. This
updates the fixture to create one in the same manner as it does for
the root libraries.
(2) In the same example above, we can see linux-vdso has an empty string.
In Ubuntu 16.04, ldd will return a slightly different formatted string
which results in an empty path for the "found" shared object path. I do
not believe it has caused a problem before attempting to use abspath
on it.
Check for the empty-string case and ignore it. We don't need to check
linux-vdso, and calling abspath on it will resolve to the current
working directory.
Signed-off-by: Chris Patterson chris.patterson@canonical.com