Avoid NULL pointer deref when libsandbox is in LD_PRELOAD#800
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Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## master #800 +/- ##
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+ Coverage 66.11% 66.22% +0.11%
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Lines 14494 14494
Branches 2534 2534
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I'm kind of baffled by the test failures; I cannot reproduce them. I pushed a revert to see if this is some issue with the Github CI environment, but if you have a better idea of what is wrong please let me know. |
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The failure might be just flakiness. I've re run failed tests. I had no time to check that earlier. Change looks OK, so I do not expect any issues with that PR. |
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If libsandbox[1] is in the LD_PRELOAD, it calls dlopen() inside a constructor function. If this constructor happens to run before the init() function in libaloader.c, dlopen_orig will still be NULL and the program will crash with a segfault. Avoid this by calling dlsym() inside the dlopen() wrapper itself when necessary. [1] https://github.com/gentoo/sandbox Bug: https://bugs.gentoo.org/973030
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arkq
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May 12, 2026
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libsandbox[1] calls dlopen() inside a constructor function. If this constructor happens to run before the init() function in libaloader.c, dlopen_orig will still be NULL and the program will crash with a segfault.
Avoid this by calling dlsym() inside the dlopen() wrapper itself when necessary.
[1] https://github.com/gentoo/sandbox
Bug: https://bugs.gentoo.org/973030