Don't keep the store open in by_store_ctrl_ex - 3.0 #28385
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Previously openssl#27529 made a change to `by_store_ctrl_ex` in order to open the OSSL_STORE early. The reason given in that PR is: "This way, we can call OSSL_STORE_open_ex() in by_store_ctrl_ex(), and get to see possible errors when the URI is loaded" That PR then kept the store open until cache_objects is called and then reused it. Unfortunately by the time cache_objects() is called we could be in a multi-threaded scenario where the X509_STORE is being shared by multiple threads. We then get a race condition where multiple threads are all using (and ultimately closing) the same `OSSL_STORE_CTX`. The purpose of keeping the `OSSL_STORE` object between by_store_ctrl_ex() and `cache_objects` is presumably an optimisation to avoid having to open the store twice. But this does not work because of the above issue. We just take the hit and open it again. Fixes openssl#28171
Check we don't have any threading issues when accessing an X509_STORE simultaneously
When looking in the stack of objects in the store we need to ensure we are holding a read lock for the store. Issue detected via thread sanitizer after the test from the previous commit was added.
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Previously #27529 made a change to `by_store_ctrl_ex` in order to open the OSSL_STORE early. The reason given in that PR is: "This way, we can call OSSL_STORE_open_ex() in by_store_ctrl_ex(), and get to see possible errors when the URI is loaded" That PR then kept the store open until cache_objects is called and then reused it. Unfortunately by the time cache_objects() is called we could be in a multi-threaded scenario where the X509_STORE is being shared by multiple threads. We then get a race condition where multiple threads are all using (and ultimately closing) the same `OSSL_STORE_CTX`. The purpose of keeping the `OSSL_STORE` object between by_store_ctrl_ex() and `cache_objects` is presumably an optimisation to avoid having to open the store twice. But this does not work because of the above issue. We just take the hit and open it again. Fixes #28171 Reviewed-by: Tomas Mraz <tomas@openssl.org> Reviewed-by: Saša Nedvědický <sashan@openssl.org> (Merged from #28385)
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Check we don't have any threading issues when accessing an X509_STORE simultaneously Reviewed-by: Tomas Mraz <tomas@openssl.org> Reviewed-by: Saša Nedvědický <sashan@openssl.org> (Merged from #28385)
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When looking in the stack of objects in the store we need to ensure we are holding a read lock for the store. Issue detected via thread sanitizer after the test from the previous commit was added. Reviewed-by: Tomas Mraz <tomas@openssl.org> Reviewed-by: Saša Nedvědický <sashan@openssl.org> (Merged from #28385)
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This is a backport of #28198 to the 3.0 branch.
Previously #27529 made a change to by_store_ctrl_ex in order to open the OSSL_STORE early. The reason given in that PR is:
"This way, we can call OSSL_STORE_open_ex() in by_store_ctrl_ex(), and get to see possible errors when the URI is loaded"
That PR then kept the store open until cache_objects is called and then reused it. Unfortunately by the time cache_objects() is called we could be in a multi-threaded scenario where the X509_STORE is being shared by multiple threads. We then get a race condition where multiple threads are all using (and ultimately closing) the same OSSL_STORE_CTX.
The purpose of keeping the OSSL_STORE object between by_store_ctrl_ex() and cache_objects is presumably an optimisation to avoid having to open the store twice. But this does not work because of the above issue.
We just take the hit and open it again.