From f76faeda4bd59f972d09dd9d954297f17c21dd60 Mon Sep 17 00:00:00 2001 From: "Richard W.M. Jones" Date: Sun, 26 Oct 2014 11:05:27 +0000 Subject: [PATCH] block/curl: Improve type safety of s->timeout. qemu_opt_get_number returns a uint64_t, and curl_easy_setopt expects a long (not an int). There is no warning about the latter type error because curl_easy_setopt uses a varargs argument. Store the timeout (which is a positive number of seconds) as a uint64_t. Check that the number given by the user is reasonable. Zero is permissible (meaning no timeout is enforced by cURL). Cast it to long before calling curl_easy_setopt to fix the type error. Example error message after this change has been applied: $ ./qemu-img create -f qcow2 /tmp/test.qcow2 \ -b 'json: { "file.driver":"https", "file.url":"https://foo/bar", "file.timeout":-1 }' qemu-img: /tmp/test.qcow2: Could not open 'json: { "file.driver":"https", "file.url":"https://foo/bar", "file.timeout":-1 }': timeout parameter is too large or negative: Invalid argument Signed-off-by: Richard W.M. Jones Reviewed-by: Laszlo Ersek Reviewed-by: Gonglei Signed-off-by: Stefan Hajnoczi --- block/curl.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/block/curl.c b/block/curl.c index b4157cc8b3..bbee3ca179 100644 --- a/block/curl.c +++ b/block/curl.c @@ -64,6 +64,7 @@ static CURLMcode __curl_multi_socket_action(CURLM *multi_handle, #define SECTOR_SIZE 512 #define READ_AHEAD_DEFAULT (256 * 1024) #define CURL_TIMEOUT_DEFAULT 5 +#define CURL_TIMEOUT_MAX 10000 #define FIND_RET_NONE 0 #define FIND_RET_OK 1 @@ -112,7 +113,7 @@ typedef struct BDRVCURLState { char *url; size_t readahead_size; bool sslverify; - int timeout; + uint64_t timeout; char *cookie; bool accept_range; AioContext *aio_context; @@ -390,7 +391,7 @@ static CURLState *curl_init_state(BlockDriverState *bs, BDRVCURLState *s) if (s->cookie) { curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie); } - curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, s->timeout); + curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout); curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, (void *)curl_read_cb); curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state); @@ -546,6 +547,10 @@ static int curl_open(BlockDriverState *bs, QDict *options, int flags, s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT, CURL_TIMEOUT_DEFAULT); + if (s->timeout > CURL_TIMEOUT_MAX) { + error_setg(errp, "timeout parameter is too large or negative"); + goto out_noclean; + } s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true); -- 2.11.0