openssl: Fix checks on BIO_get_mem_ptr()#20998
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ndossche wants to merge 1 commit intophp:masterfrom
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This should be master only as it cannot fail in reality. |
If the call fails, then the pointer remains uninitialized, and this triggers undefined behaviour or the reading of a dangling pointer. In my own tests this came out as a UAF. However, it seems not exploitable by an attacker as failure should be not controllable. It's worth pointing out that OpenSSL checks the return value in its own code that calls this function as well [1]. [1] https://github.com/openssl/openssl/blob/b2ecef451ccede07366023da4553f113f6e4fe71/apps/lib/apps.c#L3307-L3311
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Ok rebased for master |
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If the call fails, then the pointer remains uninitialized, and this triggers undefined behaviour or the reading of a dangling pointer. In my own tests this came out as a UAF. However, it seems not exploitable by an attacker as failure should be not controllable.
It's worth pointing out that OpenSSL checks the return value in its own code that calls this function as well [1].
[1] https://github.com/openssl/openssl/blob/b2ecef451ccede07366023da4553f113f6e4fe71/apps/lib/apps.c#L3307-L3311
This was found by a hybrid static-dynamic analyser that looks for inconsistent handling of error checks in bindings.