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[Qemu-devel] [PATCH v2] 9pfs: fix integer overflow issue in xattr read/w
From: |
Li Qiang |
Subject: |
[Qemu-devel] [PATCH v2] 9pfs: fix integer overflow issue in xattr read/write |
Date: |
Wed, 12 Oct 2016 19:53:39 -0700 |
From: Li Qiang <address@hidden>
In 9pfs xattr read/write function, it mix to use unsigned/signed
,32/64 bits integers. This will causes oob read/write issues. This patch
fix this.
Signed-off-by: Li Qiang <address@hidden>
---
hw/9pfs/9p.c | 34 +++++++++++++---------------------
hw/9pfs/9p.h | 4 ++--
2 files changed, 15 insertions(+), 23 deletions(-)
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index e4040dc..8c7488f 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -1642,20 +1642,17 @@ static int v9fs_xattr_read(V9fsState *s, V9fsPDU *pdu,
V9fsFidState *fidp,
{
ssize_t err;
size_t offset = 7;
- int read_count;
- int64_t xattr_len;
+ uint64_t read_count;
V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
VirtQueueElement *elem = v->elems[pdu->idx];
- xattr_len = fidp->fs.xattr.len;
- read_count = xattr_len - off;
+ if (fidp->fs.xattr.len < off) {
+ read_count = 0;
+ } else {
+ read_count = fidp->fs.xattr.len - off;
+ }
if (read_count > max_count) {
read_count = max_count;
- } else if (read_count < 0) {
- /*
- * read beyond XATTR value
- */
- read_count = 0;
}
err = pdu_marshal(pdu, offset, "d", read_count);
if (err < 0) {
@@ -1982,23 +1979,18 @@ static int v9fs_xattr_write(V9fsState *s, V9fsPDU *pdu,
V9fsFidState *fidp,
{
int i, to_copy;
ssize_t err = 0;
- int write_count;
- int64_t xattr_len;
+ uint64_t write_count;
size_t offset = 7;
- xattr_len = fidp->fs.xattr.len;
- write_count = xattr_len - off;
- if (write_count > count) {
- write_count = count;
- } else if (write_count < 0) {
- /*
- * write beyond XATTR value len specified in
- * xattrcreate
- */
+ if (fidp->fs.xattr.len < off) {
err = -ENOSPC;
goto out;
}
+ write_count = fidp->fs.xattr.len - off;
+ if (write_count > count) {
+ write_count = count;
+ }
err = pdu_marshal(pdu, offset, "d", write_count);
if (err < 0) {
return err;
@@ -3254,7 +3246,7 @@ static void v9fs_xattrcreate(void *opaque)
{
int flags;
int32_t fid;
- int64_t size;
+ uint64_t size;
ssize_t err = 0;
V9fsString name;
size_t offset = 7;
diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h
index d539d2e..22198f6 100644
--- a/hw/9pfs/9p.h
+++ b/hw/9pfs/9p.h
@@ -159,8 +159,8 @@ typedef struct V9fsConf
typedef struct V9fsXattr
{
- int64_t copied_len;
- int64_t len;
+ uint64_t copied_len;
+ uint64_t len;
void *value;
V9fsString name;
int flags;
--
1.8.3.1
- [Qemu-devel] [PATCH v2] 9pfs: fix integer overflow issue in xattr read/write,
Li Qiang <=