From: Samuel Holland <samuel@sholland.org>
Date: Sun, 21 Jul 2019 04:52:26 +0000 (-0500)
Subject: use the correct stat structure in the fstat path
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;h=0ce49d0a301b4142741b32773492af90f66ed3ca;p=musl

use the correct stat structure in the fstat path

commit 01ae3fc6d48f4a45535189b7a6db286535af08ca modified fstatat to
translate the kernel's struct stat ("kstat") into the libc struct stat.
To do this, it created a local kstat object, and copied its contents
into the user-provided object.

However, the commit neglected to update the fstat compatibility path and
its fallbacks. They continued to pass the user-supplied object to the
kernel, later overwiting it with the uninitialized memory in the local
temporary.
---

diff --git a/src/stat/fstatat.c b/src/stat/fstatat.c
index 7de75462..d915fa10 100644
--- a/src/stat/fstatat.c
+++ b/src/stat/fstatat.c
@@ -67,16 +67,16 @@ static int fstatat_kstat(int fd, const char *restrict path, struct stat *restric
 	struct kstat kst;
 
 	if (flag==AT_EMPTY_PATH && fd>=0 && !*path) {
-		ret = __syscall(SYS_fstat, fd, st);
+		ret = __syscall(SYS_fstat, fd, &kst);
 		if (ret==-EBADF && __syscall(SYS_fcntl, fd, F_GETFD)>=0) {
-			ret = __syscall(SYS_fstatat, fd, path, st, flag);
+			ret = __syscall(SYS_fstatat, fd, path, &kst, flag);
 			if (ret==-EINVAL) {
 				char buf[15+3*sizeof(int)];
 				__procfdname(buf, fd);
 #ifdef SYS_stat
-				ret = __syscall(SYS_stat, buf, st);
+				ret = __syscall(SYS_stat, buf, &kst);
 #else
-				ret = __syscall(SYS_fstatat, AT_FDCWD, buf, st, 0);
+				ret = __syscall(SYS_fstatat, AT_FDCWD, buf, &kst, 0);
 #endif
 			}
 		}