From 209c569ce277261027bd4de8d36ca73e53bd31c0 Mon Sep 17 00:00:00 2001 From: emaste Date: Wed, 5 Dec 2018 21:51:39 +0000 Subject: [PATCH] MFC r341484: Always treat firmware request and response sizes as unsigned. This fixes an incomplete bounds check on the guest-supplied request size where a very large request size could be interpreted as a negative value and not be caught by the bounds check. Submitted by: jhb Reported by: Reno Robert Security: CVE-2018-17160 git-svn-id: svn://svn.freebsd.org/base/stable/10@341607 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f --- usr.sbin/bhyve/fwctl.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/usr.sbin/bhyve/fwctl.c b/usr.sbin/bhyve/fwctl.c index 9e90c1ade..33d966b61 100644 --- a/usr.sbin/bhyve/fwctl.c +++ b/usr.sbin/bhyve/fwctl.c @@ -77,8 +77,8 @@ static u_int ident_idx; struct op_info { int op; - int (*op_start)(int len); - void (*op_data)(uint32_t data, int len); + int (*op_start)(uint32_t len); + void (*op_data)(uint32_t data, uint32_t len); int (*op_result)(struct iovec **data); void (*op_done)(struct iovec *data); }; @@ -117,7 +117,7 @@ errop_set(int err) } static int -errop_start(int len) +errop_start(uint32_t len) { errop_code = ENOENT; @@ -126,7 +126,7 @@ errop_start(int len) } static void -errop_data(uint32_t data, int len) +errop_data(uint32_t data, uint32_t len) { /* ignore */ @@ -186,7 +186,7 @@ static int fget_cnt; static size_t fget_size; static int -fget_start(int len) +fget_start(uint32_t len) { if (len > FGET_STRSZ) @@ -198,7 +198,7 @@ fget_start(int len) } static void -fget_data(uint32_t data, int len) +fget_data(uint32_t data, uint32_t len) { *((uint32_t *) &fget_str[fget_cnt]) = data; @@ -283,8 +283,8 @@ static struct req_info { struct op_info *req_op; int resp_error; int resp_count; - int resp_size; - int resp_off; + size_t resp_size; + size_t resp_off; struct iovec *resp_biov; } rinfo; @@ -344,13 +344,14 @@ fwctl_request_start(void) static int fwctl_request_data(uint32_t value) { - int remlen; /* Make sure remaining size is >= 0 */ - rinfo.req_size -= sizeof(uint32_t); - remlen = MAX(rinfo.req_size, 0); + if (rinfo.req_size <= sizeof(uint32_t)) + rinfo.req_size = 0; + else + rinfo.req_size -= sizeof(uint32_t); - (*rinfo.req_op->op_data)(value, remlen); + (*rinfo.req_op->op_data)(value, rinfo.req_size); if (rinfo.req_size < sizeof(uint32_t)) { fwctl_request_done(); @@ -399,7 +400,7 @@ static int fwctl_response(uint32_t *retval) { uint32_t *dp; - int remlen; + ssize_t remlen; switch(rinfo.resp_count) { case 0: @@ -434,7 +435,7 @@ fwctl_response(uint32_t *retval) } if (rinfo.resp_count > 3 && - rinfo.resp_size - rinfo.resp_off <= 0) { + rinfo.resp_off >= rinfo.resp_size) { fwctl_response_done(); return (1); } -- 2.42.0