Hello, The attached patch %-escapes debuginfod url characters, then unescapes only '/' characters. Previously characters such as '+' were not escaped and caused improper escaping further on in handler_cb. https://sourceware.org/bugzilla/show_bug.cgi?id=28034.
On Wed, Sep 8, 2021 at 9:38 AM Mark Wielaard <m...@klomp.org> wrote: > /* Initialize each handle. */ > for (int i = 0; i < num_urls; i++) > > So you only need to escape once. You of course then need to make sure > the escaped_string is freed after the loop. Added > We already check that the first char is a '/'. It seems silly to curl > escape that one and then unescape it again. So maybe curl_easy_escape > (data[i].handle, filename + 1, 0) and then change the snprintf pattern > to "%s/%s/%s/%s"? > ^ the slash got readded here. Added > The strlen inside the while loop can also be done outside and then > calculated instead of running strlen on the tail every time. Added > Lastly I assume there are already testcases that cover this > functionality? Just wanting to know how you tested it. Previously, with run-debuginfod-find.sh the test was embedded within other tests. Now the test is independent and has been added to the list of TESTS. Regards, Noah Sanci
From a080fd3feb79d601d86c54cf479562d6d5bed395 Mon Sep 17 00:00:00 2001 From: Noah Sanci <nsa...@redhat.com> Date: Thu, 9 Sep 2021 13:10:33 -0400 Subject: [PATCH] debuginfod: PR28034 - Percent escape debuginfod urls When requesting some source files, some URL-inconvenient chars sometimes pop up, including but not limited to '+', '^', and '&'. Example from f33 libstdc++: /buildid/44d8485cb75512c2ca5c8f70afbd475cae30af4f/source/usr/src/debug /gcc-10.3.1-1.fc33.x86_64/obj-x86_64-redhat-linux/x86_64-redhat-linux/ libstdc++-v3/src/c++11/../../../../../libstdc++-v3/src/c++11/ condition_variable.cc As this URL is passed into debuginfod's handler_cb, it appears that the + signs are helpfully unescaped to spaces by libmicrohttpd, which 'course breaks everything. To combat this, before querying the debuginfod daemon, clients now % escape the source filename. This converts many alphanumeric characters into their %-code format, including '/' to %2F. We want to preserve the '/' in the url, so after conversion replace %2Fs with a '/'. https://sourceware.org/bugzilla/show_bug.cgi?id=28034 Signed-off-by: Noah Sanci <nsa...@redhat.com> --- debuginfod/debuginfod-client.c | 18 ++++++-- tests/ChangeLog | 7 +-- tests/Makefile.am | 2 + tests/run-debuginfod-percent-escape.sh | 60 ++++++++++++++++++++++++++ 4 files changed, 79 insertions(+), 8 deletions(-) create mode 100755 tests/run-debuginfod-percent-escape.sh diff --git a/debuginfod/debuginfod-client.c b/debuginfod/debuginfod-client.c index d41723ce..77ca844b 100644 --- a/debuginfod/debuginfod-client.c +++ b/debuginfod/debuginfod-client.c @@ -883,6 +883,10 @@ debuginfod_query_server (debuginfod_client *c, data[i].errbuf[0] = '\0'; } + char *escaped_string; + if (filename) + escaped_string = curl_easy_escape(&target_handle, filename+1, 0); + /* Initialize each handle. */ for (int i = 0; i < num_urls; i++) { @@ -904,16 +908,23 @@ debuginfod_query_server (debuginfod_client *c, if (filename) /* must start with / */ { /* PR28034 escape characters in completed url to %hh format. */ - char *escaped_string; - escaped_string = curl_easy_escape(data[i].handle, filename, 0); + char *loc = escaped_string; if (!escaped_string) { rc = -ENOMEM; goto out2; } + + size_t escaped_strlen = strlen(escaped_string); + while ((loc = strstr(loc, "%2F"))) + { + loc[0] = '/'; + // pull the string back after replacement + memmove(loc+1, loc+3,escaped_strlen - (loc - escaped_string + 2) ); + escaped_strlen -=2; + } snprintf(data[i].url, PATH_MAX, "%s/%s/%s/%s", server_url, build_id_bytes, type, escaped_string); - curl_free(escaped_string); } else snprintf(data[i].url, PATH_MAX, "%s/%s/%s", server_url, build_id_bytes, type); @@ -953,6 +964,7 @@ debuginfod_query_server (debuginfod_client *c, curl_multi_add_handle(curlm, data[i].handle); } + if (filename) curl_free(escaped_string); /* Query servers in parallel. */ if (vfd >= 0) dprintf (vfd, "query %d urls in parallel\n", num_urls); diff --git a/tests/ChangeLog b/tests/ChangeLog index 85dca442..b84f420c 100644 --- a/tests/ChangeLog +++ b/tests/ChangeLog @@ -132,11 +132,8 @@ 2021-07-16 Noah Sanci <nsa...@redhat.com> PR28034 - * run-debuginfod-find.sh: Added a test ensuring files with % - escapable characters in their paths are accessible. The test - itself is changing the name of a binary known previously as prog to - p+r%o$g. General operations such as accessing p+r%o$g acts as the - test for %-escape checking. + * run-debuginfod-percent-escape.sh: Added a test ensuring files with % + escapable characters in their paths are accessible. 2021-07-21 Noah Sanci <nsa...@redhat.com> diff --git a/tests/Makefile.am b/tests/Makefile.am index c586422e..ee17d3b1 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -231,6 +231,7 @@ TESTS += run-debuginfod-dlopen.sh \ run-debuginfod-federation-sqlite.sh \ run-debuginfod-federation-link.sh \ run-debuginfod-federation-metrics.sh \ + run-debuginfod-percent-escape.sh \ run-debuginfod-x-forwarded-for.sh endif endif @@ -515,6 +516,7 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh run-ar.sh \ run-debuginfod-archive-groom.sh \ run-debuginfod-archive-rename.sh \ run-debuginfod-archive-test.sh \ + run-debuginfod-percent-escape.sh \ debuginfod-rpms/fedora30/hello2-1.0-2.src.rpm \ debuginfod-rpms/fedora30/hello2-1.0-2.x86_64.rpm \ debuginfod-rpms/fedora30/hello2-debuginfo-1.0-2.x86_64.rpm \ diff --git a/tests/run-debuginfod-percent-escape.sh b/tests/run-debuginfod-percent-escape.sh new file mode 100755 index 00000000..f7d8dc66 --- /dev/null +++ b/tests/run-debuginfod-percent-escape.sh @@ -0,0 +1,60 @@ +#!/usr/bin/env bash +# +# Copyright (C) 2019-2021 Red Hat, Inc. +# This file is part of elfutils. +# +# This file is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# elfutils is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. + +. $srcdir/debuginfod-subr.sh # includes set -e +# for test case debugging, uncomment: +set -x +unset VALGRIND_CMD +# This variable is essential and ensures no time-race for claiming ports occurs +# set base to a unique multiple of 100 not used in any other 'run-debuginfod-*' test +base=10000 +get_ports +DB=${PWD}/.debuginfod_tmp.sqlite +tempfiles $DB +mkdir F +env LD_LIBRARY_PATH=$ldpath ${abs_builddir}/../debuginfod/debuginfod $VERBOSE \ + -F -R -d $DB -p $PORT1 -t0 -g0 -v R ${PWD}/F > vlog$PORT1 2>&1 & +PID1=$! +tempfiles vlog$PORT1 +errfiles vlog$PORT1 +# Server must become ready +wait_ready $PORT1 'ready' 1 +# Be patient when run on a busy machine things might take a bit. + +# Build a non-stripped binary +echo "int main() { return 0; }" > ${PWD}/F/p++r\$\#o^^g.c +gcc -Wl,--build-id -g -o ${PWD}/F/p++r\$\#o^^g ${PWD}/F/p++r\$\#o^^g.c +BUILDID=`env LD_LIBRARY_PATH=$ldpath ${abs_builddir}/../src/readelf \ + -a ${PWD}/F/p++r\\$\#o^^g | grep 'Build ID' | cut -d ' ' -f 7` +tempfiles ${PWD}/F/p++r\$\#o^^g.c ${PWD}/F/p++r\$\#o^^g +kill -USR1 $PID1 +# Now there should be 1 files in the index +wait_ready $PORT1 'thread_work_total{role="traverse"}' 1 +wait_ready $PORT1 'thread_work_pending{role="scan"}' 0 +wait_ready $PORT1 'thread_busy{role="scan"}' 0 +rm -rf $DEBUGINFOD_CACHE_PATH # clean it from previous tests +ls F +env DEBUGINFOD_CACHE_PATH=${PWD}/.client_cache DEBUGINFOD_URLS="http://127.0.0.1:$PORT1"; \ + LD_LIBRARY_PATH=$ldpath ${abs_top_builddir}/debuginfod/debuginfod-find -vvv source F/p++r\$\#o^^g ${abs_builddir}/F/p++r\$\#o^^g.c > vlog1 2>&1 || true +tempfiles vlog1 +grep 'F/p%2B%2Br%24%23o%5E%5Eg.c' vlog1 + +kill $PID1 +wait $PID1 +PID1=0 +exit 0 -- 2.31.1
