From 8071d966ee940311a0e93d07e82b398c50705a6c Mon Sep 17 00:00:00 2001 From: Christopher Degawa Date: Sat, 28 May 2022 14:53:54 -0500 Subject: [PATCH] winansi: check result and Buffer before using Name NtQueryObject under Wine can return a success but fill out no name. In those situations, Wine will set Buffer to NULL, and set result to the sizeof(OBJECT_NAME_INFORMATION). Running a command such as echo "$(git.exe --version 2>/dev/null)" will crash due to a NULL pointer dereference when the code attempts to null terminate the buffer, although, weirdly, removing the subshell or redirecting stdout to a file will not trigger the crash. Code has been added to also check Buffer and Length to ensure the check is as robust as possible due to the current behavior being fragile at best, and could potentially change in the future This code is based on the behavior of NtQueryObject under wine and reactos. Signed-off-by: Christopher Degawa --- compat/winansi.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/compat/winansi.c b/compat/winansi.c index 1b3f916b9fc409..121bff22547f51 100644 --- a/compat/winansi.c +++ b/compat/winansi.c @@ -573,6 +573,9 @@ static void detect_msys_tty(int fd) if (!NT_SUCCESS(NtQueryObject(h, ObjectNameInformation, buffer, sizeof(buffer) - 2, &result))) return; + if (result < sizeof(*nameinfo) || !nameinfo->Name.Buffer || + !nameinfo->Name.Length) + return; name = nameinfo->Name.Buffer; name[nameinfo->Name.Length / sizeof(*name)] = 0;