From: Laurent Vivier <laurent@vivier.eu>
Date: Tue, 27 Sep 2022 12:43:57 +0000 (+0200)
Subject: linux-user: don't use AT_EXECFD in do_openat()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=00ed8a3459869f46dbb4e18d4dcc81882dfe8776;p=qemu.git

linux-user: don't use AT_EXECFD in do_openat()

AT_EXECFD gives access to the binary file even if
it is not readable (only executable).

Moreover it can be opened with flags and mode that are not the ones
provided by do_openat() caller.

And it is not available because loader_exec() has closed it.

To avoid that, use only safe_openat() with the exec_path.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220927124357.688536-3-laurent@vivier.eu>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index a7a29091c9..665db67c05 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -8251,8 +8251,7 @@ static int do_openat(CPUArchState *cpu_env, int dirfd, const char *pathname, int
     };
 
     if (is_proc_myself(pathname, "exe")) {
-        int execfd = qemu_getauxval(AT_EXECFD);
-        return execfd ? execfd : safe_openat(dirfd, exec_path, flags, mode);
+        return safe_openat(dirfd, exec_path, flags, mode);
     }
 
     for (fake_open = fakes; fake_open->filename; fake_open++) {