Hi, The condition is : 74. if (TupIsNull(slot)) is true 85. if (TupIsNull(resultTupleSlot)) is true too.
If resultTupleSlot is not can be NULL, why test if (TupIsNull(resultTupleSlot))? Occurring these two conditions ExecClearTuple is called, but, don't check by NULL arg. There are at least 2 more possible cases, envolving ExecClearTuple: nodeFunctionscan.c and nodeWindowAgg.c Best regards, Ranier Vilela ________________________________________ De: Daniel Gustafsson <dan...@yesql.se> Enviado: terça-feira, 12 de novembro de 2019 13:43 Para: Ranier Vilela Cc: PostgreSQL Hackers Assunto: Re: [PATCH][BUG_FIX] Potential null pointer dereferencing. > On 12 Nov 2019, at 14:07, Ranier Vilela <ranier_...@hotmail.com> wrote: > ExecClearTuple don't check por NULL pointer arg and according > TupIsNull slot can be NULL. I assume you are referring to the TupIsNull(resultTupleSlot) check a few lines down in the same loop? If resultTupleSlot was indeed NULL and not empty, the subsequent call to ExecCopySlot would be a NULL pointer dereference too. I might be missing something obvious, but in which case can resultTupleSlot be NULL when calling ExecUnique? cheers ./daniel
