* [Qemu-devel] [PATCH] Fix linux-user crashes in ioctl(SIOCGIFCONF) when ifc_buf is NULL.
@ 2018-10-09 7:10 Kan Li
0 siblings, 0 replies; 2+ messages in thread
From: Kan Li @ 2018-10-09 7:10 UTC (permalink / raw)
To: qemu-devel
Summary:
This is to fix bug https://bugs.launchpad.net/qemu/+bug/1796754.
It is valid for ifc_buf to be NULL according to
http://man7.org/linux/man-pages/man7/netdevice.7.html.
Signed-off-by: Kan Li <likan_999.student@sina.com>
---
linux-user/syscall.c | 56 ++++++++++++++++++++++++--------------------
1 file changed, 31 insertions(+), 25 deletions(-)
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index ae3c0dfef7..fbab98d4f7 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -4134,28 +4134,33 @@ static abi_long do_ioctl_ifconf(const IOCTLEntry *ie, uint8_t *buf_temp,
unlock_user(argptr, arg, 0);
host_ifconf = (struct ifconf *)(unsigned long)buf_temp;
- target_ifc_len = host_ifconf->ifc_len;
target_ifc_buf = (abi_long)(unsigned long)host_ifconf->ifc_buf;
- target_ifreq_size = thunk_type_size(ifreq_arg_type, 0);
- nb_ifreq = target_ifc_len / target_ifreq_size;
- host_ifc_len = nb_ifreq * sizeof(struct ifreq);
+ if (target_ifc_buf != 0) {
+ target_ifc_len = host_ifconf->ifc_len;
- outbufsz = sizeof(*host_ifconf) + host_ifc_len;
- if (outbufsz > MAX_STRUCT_SIZE) {
- /* We can't fit all the extents into the fixed size buffer.
- * Allocate one that is large enough and use it instead.
- */
- host_ifconf = malloc(outbufsz);
- if (!host_ifconf) {
- return -TARGET_ENOMEM;
+ target_ifreq_size = thunk_type_size(ifreq_arg_type, 0);
+ nb_ifreq = target_ifc_len / target_ifreq_size;
+ host_ifc_len = nb_ifreq * sizeof(struct ifreq);
+
+ outbufsz = sizeof(*host_ifconf) + host_ifc_len;
+ if (outbufsz > MAX_STRUCT_SIZE) {
+ /* We can't fit all the extents into the fixed size buffer.
+ * Allocate one that is large enough and use it instead.
+ */
+ host_ifconf = malloc(outbufsz);
+ if (!host_ifconf) {
+ return -TARGET_ENOMEM;
+ }
+ memcpy(host_ifconf, buf_temp, sizeof(*host_ifconf));
+ free_buf = 1;
}
- memcpy(host_ifconf, buf_temp, sizeof(*host_ifconf));
- free_buf = 1;
- }
- host_ifc_buf = (char*)host_ifconf + sizeof(*host_ifconf);
+ host_ifc_buf = (char*)host_ifconf + sizeof(*host_ifconf);
- host_ifconf->ifc_len = host_ifc_len;
+ host_ifconf->ifc_len = host_ifc_len;
+ } else {
+ host_ifc_buf = NULL;
+ }
host_ifconf->ifc_buf = host_ifc_buf;
ret = get_errno(safe_ioctl(fd, ie->host_cmd, host_ifconf));
@@ -4178,15 +4183,16 @@ static abi_long do_ioctl_ifconf(const IOCTLEntry *ie, uint8_t *buf_temp,
thunk_convert(argptr, host_ifconf, arg_type, THUNK_TARGET);
unlock_user(argptr, arg, target_size);
- /* copy ifreq[] to target user */
-
- argptr = lock_user(VERIFY_WRITE, target_ifc_buf, target_ifc_len, 0);
- for (i = 0; i < nb_ifreq ; i++) {
- thunk_convert(argptr + i * target_ifreq_size,
- host_ifc_buf + i * sizeof(struct ifreq),
- ifreq_arg_type, THUNK_TARGET);
+ if (target_ifc_buf != 0) {
+ /* copy ifreq[] to target user */
+ argptr = lock_user(VERIFY_WRITE, target_ifc_buf, target_ifc_len, 0);
+ for (i = 0; i < nb_ifreq ; i++) {
+ thunk_convert(argptr + i * target_ifreq_size,
+ host_ifc_buf + i * sizeof(struct ifreq),
+ ifreq_arg_type, THUNK_TARGET);
+ }
+ unlock_user(argptr, target_ifc_buf, target_ifc_len);
}
- unlock_user(argptr, target_ifc_buf, target_ifc_len);
}
if (free_buf) {
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [Qemu-devel] [PATCH] Fix linux-user crashes in ioctl(SIOCGIFCONF) when ifc_buf is NULL.
@ 2018-10-09 7:29 Kan Li
0 siblings, 0 replies; 2+ messages in thread
From: Kan Li @ 2018-10-09 7:29 UTC (permalink / raw)
To: qemu-devel
Summary:
This is to fix bug https://bugs.launchpad.net/qemu/+bug/1796754.
It is valid for ifc_buf to be NULL according to
http://man7.org/linux/man-pages/man7/netdevice.7.html.
Signed-off-by: Kan Li <likan_999.student@sina.com>
---
linux-user/syscall.c | 56 ++++++++++++++++++++++++--------------------
1 file changed, 31 insertions(+), 25 deletions(-)
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index ae3c0dfef7..fbab98d4f7 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -4134,28 +4134,33 @@ static abi_long do_ioctl_ifconf(const IOCTLEntry *ie, uint8_t *buf_temp,
unlock_user(argptr, arg, 0);
host_ifconf = (struct ifconf *)(unsigned long)buf_temp;
- target_ifc_len = host_ifconf->ifc_len;
target_ifc_buf = (abi_long)(unsigned long)host_ifconf->ifc_buf;
- target_ifreq_size = thunk_type_size(ifreq_arg_type, 0);
- nb_ifreq = target_ifc_len / target_ifreq_size;
- host_ifc_len = nb_ifreq * sizeof(struct ifreq);
+ if (target_ifc_buf != 0) {
+ target_ifc_len = host_ifconf->ifc_len;
- outbufsz = sizeof(*host_ifconf) + host_ifc_len;
- if (outbufsz > MAX_STRUCT_SIZE) {
- /* We can't fit all the extents into the fixed size buffer.
- * Allocate one that is large enough and use it instead.
- */
- host_ifconf = malloc(outbufsz);
- if (!host_ifconf) {
- return -TARGET_ENOMEM;
+ target_ifreq_size = thunk_type_size(ifreq_arg_type, 0);
+ nb_ifreq = target_ifc_len / target_ifreq_size;
+ host_ifc_len = nb_ifreq * sizeof(struct ifreq);
+
+ outbufsz = sizeof(*host_ifconf) + host_ifc_len;
+ if (outbufsz > MAX_STRUCT_SIZE) {
+ /* We can't fit all the extents into the fixed size buffer.
+ * Allocate one that is large enough and use it instead.
+ */
+ host_ifconf = malloc(outbufsz);
+ if (!host_ifconf) {
+ return -TARGET_ENOMEM;
+ }
+ memcpy(host_ifconf, buf_temp, sizeof(*host_ifconf));
+ free_buf = 1;
}
- memcpy(host_ifconf, buf_temp, sizeof(*host_ifconf));
- free_buf = 1;
- }
- host_ifc_buf = (char*)host_ifconf + sizeof(*host_ifconf);
+ host_ifc_buf = (char*)host_ifconf + sizeof(*host_ifconf);
- host_ifconf->ifc_len = host_ifc_len;
+ host_ifconf->ifc_len = host_ifc_len;
+ } else {
+ host_ifc_buf = NULL;
+ }
host_ifconf->ifc_buf = host_ifc_buf;
ret = get_errno(safe_ioctl(fd, ie->host_cmd, host_ifconf));
@@ -4178,15 +4183,16 @@ static abi_long do_ioctl_ifconf(const IOCTLEntry *ie, uint8_t *buf_temp,
thunk_convert(argptr, host_ifconf, arg_type, THUNK_TARGET);
unlock_user(argptr, arg, target_size);
- /* copy ifreq[] to target user */
-
- argptr = lock_user(VERIFY_WRITE, target_ifc_buf, target_ifc_len, 0);
- for (i = 0; i < nb_ifreq ; i++) {
- thunk_convert(argptr + i * target_ifreq_size,
- host_ifc_buf + i * sizeof(struct ifreq),
- ifreq_arg_type, THUNK_TARGET);
+ if (target_ifc_buf != 0) {
+ /* copy ifreq[] to target user */
+ argptr = lock_user(VERIFY_WRITE, target_ifc_buf, target_ifc_len, 0);
+ for (i = 0; i < nb_ifreq ; i++) {
+ thunk_convert(argptr + i * target_ifreq_size,
+ host_ifc_buf + i * sizeof(struct ifreq),
+ ifreq_arg_type, THUNK_TARGET);
+ }
+ unlock_user(argptr, target_ifc_buf, target_ifc_len);
}
- unlock_user(argptr, target_ifc_buf, target_ifc_len);
}
if (free_buf) {
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
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2018-10-09 7:10 [Qemu-devel] [PATCH] Fix linux-user crashes in ioctl(SIOCGIFCONF) when ifc_buf is NULL Kan Li
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