Re: [libvirt] [PATCH v2 2/3] hyperv: Escape WQL queries

The code was vulnerable to SQL injection. Likely not a security issue due to WMI SQL and other constraints but still lame. For example: virsh # dominfo \" error: failed to get domain '"' error: internal error: SOAP fault during enumeration: code 's:Sender', subcode 'n:CannotProcessFilter', reason 'The data source could not process the filter. The filter might be missing or it might be invalid. Change the filter and try the request again. ', detail 'The WS-Management service cannot process the request. The WQL query is invalid. ' This commit fixes the Hyper-V driver by escaping all WMI SQL string parameters. The same command with the fix: virsh # dominfo \" error: failed to get domain '"' error: Domain not found: No domain with name " Signed-off-by: Ladi Prosek <lprosek(a)redhat.com&gt; --- src/hyperv/hyperv_driver.c | 96 +++++++++++++++++++++++----------------------- src/hyperv/hyperv_wmi.c | 2 +- src/util/virbuffer.c | 18 +++++++++ src/util/virbuffer.h | 3 ++ 4 files changed, 70 insertions(+), 49 deletions(-)

diff --git a/src/util/virbuffer.c b/src/util/virbuffer.c index 28a291bb0..15f6e21fb 100644 --- a/src/util/virbuffer.c +++ b/src/util/virbuffer.c @@ -575,6 +575,24 @@ virBufferEscapeRegex(virBufferPtr buf, }

/** + * virBufferEscapeSQL: + * @buf: the buffer to append to + * @format: a printf like format string but with only one %s parameter + * @str: the string argument which needs to be escaped + * + * Do a formatted print with a single string to a buffer. The @str is + * escaped to prevent SQL injection (format is expected to contain \"%s\"). + * Auto indentation may be applied. + */ +void +virBufferEscapeSQL(virBufferPtr buf, + const char *format, + const char *str) +{ + virBufferEscape(buf, '\\', "'\"\\", format, str); +} + +/** * virBufferEscape: * @buf: the buffer to append to * @escape: the escape character to inject diff --git a/src/util/virbuffer.h b/src/util/virbuffer.h index 3211c07b0..4f5ed162f 100644 --- a/src/util/virbuffer.h +++ b/src/util/virbuffer.h @@ -93,6 +93,9 @@ void virBufferEscapeSexpr(virBufferPtr buf, const char *format, void virBufferEscapeRegex(virBufferPtr buf, const char *format, const char *str); +void virBufferEscapeSQL(virBufferPtr buf, + const char *format, + const char *str); void virBufferEscapeShell(virBufferPtr buf, const char *str); void virBufferURIEncodeString(virBufferPtr buf, const char *str);