fix: Vec.as_ptr() might return a dangling pointer #760
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Both [as_ptr][as_ptr] and [as_mut_ptr][as_mut_ptr] are allowed to return a dangling raw pointer when the Vec size is 0. The idea is that you should guard that read checking the size. This probably works well in most cases, but at the very least in the java-sdk, the JNA machinery tries to be helpful and it dereferences the pointer, causing a SIGSEGV. The solution is to check if the resulting vector is empty and return null instead. A new, empty vector would be better, but I think that would not solve the problem, because the problem is caused by a new, empty vector in the first place. Caveat: this might break consumers downstream. On the other hand: consumers that do not check for the nInput, nOutput counts are just waiting to explode, like JNA. [as_ptr]: https://doc.rust-lang.org/std/vec/struct.Vec.html#method.as_ptr [as_mut_ptr]: https://doc.rust-lang.org/std/vec/struct.Vec.html#method.as_mut_ptr Signed-off-by: Edoardo Vacchi <evacchi@users.noreply.github.com>
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This addresses extism#27 once we merge extism/extism#760 and release a new version of libextism. This PR simply check the parameters for null and the counts to be valid, in preparation for extism/extism#760 which otherwise would cause a NullPointerException when outputs and inputs are empty. Signed-off-by: Edoardo Vacchi <evacchi@users.noreply.github.com>
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This addresses extism#27 once we merge extism/extism#760 and release a new version of libextism. This PR simply check the parameters for null and the counts to be valid, in preparation for extism/extism#760 which otherwise would cause a NullPointerException when outputs and inputs are empty. Signed-off-by: Edoardo Vacchi <evacchi@users.noreply.github.com>
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This addresses #27 once we merge extism/extism#760 and release a new version of libextism. This PR simply check the parameters for null and the counts to be valid, in preparation for extism/extism#760 which otherwise would cause a NullPointerException when outputs and inputs are empty. Signed-off-by: Edoardo Vacchi <evacchi@users.noreply.github.com>
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Both as_ptr and as_mut_ptr are allowed to return a dangling raw pointer when the Vec size is 0.
The idea is that you should guard that read checking the size. This probably works well in most cases, but at the very least in the java-sdk, the JNA machinery tries to be helpful and it dereferences the pointer, causing a SIGSEGV.
The solution is to check if the resulting vector is empty and return null instead. A new, empty vector would be better, but I think that would not solve the problem, because the problem is caused by a new, empty vector in the first place.
Caveat: this might break consumers downstream.
On the other hand: consumers that do not check for the nInput, nOutput counts are just waiting to explode, like JNA.
This addresses extism/java-sdk#27