qemu/0052-9pfs-allocate-space-for-guest-origi.patch
Andreas Färber 3430f55120 Accepting request 441247 from home:bfrogers:branches:Virtualization
Refine the reproducible build changes to no longer override linux commands, but rather fix via patches only. Also fix all the recent security issues reported.

OBS-URL: https://build.opensuse.org/request/show/441247
OBS-URL: https://build.opensuse.org/package/show/Virtualization/qemu?expand=0&rev=320
2016-11-21 17:05:46 +00:00

59 lines
2.3 KiB
Diff

From 2d4128223e6b5a3dff30e0b07435620f1092c5ae Mon Sep 17 00:00:00 2001
From: Li Qiang <liqiang6-s@360.cn>
Date: Mon, 17 Oct 2016 14:13:58 +0200
Subject: [PATCH] 9pfs: allocate space for guest originated empty strings
If a guest sends an empty string paramater to any 9P operation, the current
code unmarshals it into a V9fsString equal to { .size = 0, .data = NULL }.
This is unfortunate because it can cause NULL pointer dereference to happen
at various locations in the 9pfs code. And we don't want to check str->data
everywhere we pass it to strcmp() or any other function which expects a
dereferenceable pointer.
This patch enforces the allocation of genuine C empty strings instead, so
callers don't have to bother.
Out of all v9fs_iov_vunmarshal() users, only v9fs_xattrwalk() checks if
the returned string is empty. It now uses v9fs_string_size() since
name.data cannot be NULL anymore.
Signed-off-by: Li Qiang <liqiang6-s@360.cn>
[groug, rewritten title and changelog,
fix empty string check in v9fs_xattrwalk()]
Signed-off-by: Greg Kurz <groug@kaod.org>
(cherry picked from commit ba42ebb863ab7d40adc79298422ed9596df8f73a)
[BR: CVE-2016-8578 BSC#1003894]
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
fsdev/9p-iov-marshal.c | 2 +-
hw/9pfs/9p.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/fsdev/9p-iov-marshal.c b/fsdev/9p-iov-marshal.c
index 663cad5..1d16f8d 100644
--- a/fsdev/9p-iov-marshal.c
+++ b/fsdev/9p-iov-marshal.c
@@ -125,7 +125,7 @@ ssize_t v9fs_iov_vunmarshal(struct iovec *out_sg, int out_num, size_t offset,
str->data = g_malloc(str->size + 1);
copied = v9fs_unpack(str->data, out_sg, out_num, offset,
str->size);
- if (copied > 0) {
+ if (copied >= 0) {
str->data[str->size] = 0;
} else {
v9fs_string_free(str);
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index dfe293d..a345fe3 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -3160,7 +3160,7 @@ static void v9fs_xattrwalk(void *opaque)
goto out;
}
v9fs_path_copy(&xattr_fidp->path, &file_fidp->path);
- if (name.data == NULL) {
+ if (!v9fs_string_size(&name)) {
/*
* listxattr request. Get the size first
*/