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authorMarkus Armbruster <armbru@redhat.com>2013-02-06 21:27:14 +0100
committerAnthony Liguori <aliguori@us.ibm.com>2013-02-06 16:35:17 -0600
commit82e59a676c01b3df3b53998d428d0a64a55f2439 (patch)
treec57a24a95c993f67f20b55a2d2510a06aacdcd1c
parent15af6321f4d1f90d0ae1b5cb05093c48b41c4533 (diff)
qmp: Fix design bug and read beyond buffer in memchar-write
Command memchar-write takes data and size parameter. Begs the question what happens when data doesn't match size. With format base64, qmp_memchar_write() copies the full data argument, regardless of size argument. With format utf8, qmp_memchar_write() copies size bytes from data, happily reading beyond data. Copies crap from the heap or even crashes. Drop the size parameter, and always copy the full data argument. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
-rw-r--r--hmp.c4
-rw-r--r--qapi-schema.json4
-rw-r--r--qemu-char.c8
-rw-r--r--qmp-commands.hx4
4 files changed, 6 insertions, 14 deletions
diff --git a/hmp.c b/hmp.c
index 1689e6f1fd..9fdf1ce516 100644
--- a/hmp.c
+++ b/hmp.c
@@ -664,13 +664,11 @@ void hmp_pmemsave(Monitor *mon, const QDict *qdict)
void hmp_memchar_write(Monitor *mon, const QDict *qdict)
{
- uint32_t size;
const char *chardev = qdict_get_str(qdict, "device");
const char *data = qdict_get_str(qdict, "data");
Error *errp = NULL;
- size = strlen(data);
- qmp_memchar_write(chardev, size, data, false, 0, &errp);
+ qmp_memchar_write(chardev, data, false, 0, &errp);
hmp_handle_error(mon, &errp);
}
diff --git a/qapi-schema.json b/qapi-schema.json
index cdd8384915..9e2cbbd1ae 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -346,8 +346,6 @@
#
# @device: the name of the memory char device.
#
-# @size: the size to write in bytes.
-#
# @data: the source data write to memchar.
#
# @format: #optional the format of the data write to chardev 'memory',
@@ -359,7 +357,7 @@
# Since: 1.4
##
{ 'command': 'memchar-write',
- 'data': {'device': 'str', 'size': 'int', 'data': 'str',
+ 'data': {'device': 'str', 'data': 'str',
'*format': 'DataFormat'} }
##
diff --git a/qemu-char.c b/qemu-char.c
index ac5d62dd9a..9c1dd1326d 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -2753,9 +2753,8 @@ static bool qemu_is_chr(const CharDriverState *chr, const char *filename)
return strcmp(chr->filename, filename);
}
-void qmp_memchar_write(const char *device, int64_t size,
- const char *data, bool has_format,
- enum DataFormat format,
+void qmp_memchar_write(const char *device, const char *data,
+ bool has_format, enum DataFormat format,
Error **errp)
{
CharDriverState *chr;
@@ -2774,12 +2773,11 @@ void qmp_memchar_write(const char *device, int64_t size,
return;
}
- write_count = (gsize)size;
-
if (has_format && (format == DATA_FORMAT_BASE64)) {
write_data = g_base64_decode(data, &write_count);
} else {
write_data = (uint8_t *)data;
+ write_count = strlen(data);
}
ret = cirmem_chr_write(chr, write_data, write_count);
diff --git a/qmp-commands.hx b/qmp-commands.hx
index bbb21f3583..8468f1022d 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -467,7 +467,7 @@ EQMP
{
.name = "memchar-write",
- .args_type = "device:s,size:i,data:s,format:s?",
+ .args_type = "device:s,data:s,format:s?",
.mhandler.cmd_new = qmp_marshal_input_memchar_write,
},
@@ -481,7 +481,6 @@ char device.
Arguments:
- "device": the name of the char device, must be unique (json-string)
-- "size": the memory size, in bytes, should be power of 2 (json-int)
- "data": the source data write to memory (json-string)
- "format": the data format write to memory, default is
utf8. (json-string, optional)
@@ -491,7 +490,6 @@ Example:
-> { "execute": "memchar-write",
"arguments": { "device": foo,
- "size": 8,
"data": "abcdefgh",
"format": "utf8" } }
<- { "return": {} }