Subject: + tools-testing-selftests-sysctl-validate-sysctl_writes_strict.patch added to -mm tree To: keescook@xxxxxxxxxxxx,rdunlap@xxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Mon, 05 May 2014 15:00:29 -0700 The patch titled Subject: tools/testing/selftests/sysctl: validate sysctl_writes_strict has been added to the -mm tree. Its filename is tools-testing-selftests-sysctl-validate-sysctl_writes_strict.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/tools-testing-selftests-sysctl-validate-sysctl_writes_strict.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/tools-testing-selftests-sysctl-validate-sysctl_writes_strict.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Kees Cook <keescook@xxxxxxxxxxxx> Subject: tools/testing/selftests/sysctl: validate sysctl_writes_strict This adds several behavioral tests to sysctl string and number writing to detect unexpected cases that behaved differently when the sysctl kernel.sysctl_writes_strict != 1. [ original ] root@localhost:~# make test_num == Testing sysctl behavior against /proc/sys/kernel/domainname == Writing test file ... ok Checking sysctl is not set to test value ... ok Writing sysctl from shell ... ok Resetting sysctl to original value ... ok Writing entire sysctl in single write ... ok Writing middle of sysctl after synchronized seek ... FAIL Writing beyond end of sysctl ... FAIL Writing sysctl with multiple long writes ... FAIL Writing entire sysctl in short writes ... FAIL Writing middle of sysctl after unsynchronized seek ... ok Checking sysctl maxlen is at least 65 ... ok Checking sysctl keeps original string on overflow append ... FAIL Checking sysctl stays NULL terminated on write ... ok Checking sysctl stays NULL terminated on overwrite ... ok make: *** [test_num] Error 1 root@localhost:~# make test_string == Testing sysctl behavior against /proc/sys/vm/swappiness == Writing test file ... ok Checking sysctl is not set to test value ... ok Writing sysctl from shell ... ok Resetting sysctl to original value ... ok Writing entire sysctl in single write ... ok Writing middle of sysctl after synchronized seek ... FAIL Writing beyond end of sysctl ... FAIL Writing sysctl with multiple long writes ... ok make: *** [test_string] Error 1 [ with CONFIG_PROC_SYSCTL_STRICT_WRITES ] root@localhost:~# make run_tests == Testing sysctl behavior against /proc/sys/kernel/domainname == Writing test file ... ok Checking sysctl is not set to test value ... ok Writing sysctl from shell ... ok Resetting sysctl to original value ... ok Writing entire sysctl in single write ... ok Writing middle of sysctl after synchronized seek ... ok Writing beyond end of sysctl ... ok Writing sysctl with multiple long writes ... ok Writing entire sysctl in short writes ... ok Writing middle of sysctl after unsynchronized seek ... ok Checking sysctl maxlen is at least 65 ... ok Checking sysctl keeps original string on overflow append ... ok Checking sysctl stays NULL terminated on write ... ok Checking sysctl stays NULL terminated on overwrite ... ok == Testing sysctl behavior against /proc/sys/vm/swappiness == Writing test file ... ok Checking sysctl is not set to test value ... ok Writing sysctl from shell ... ok Resetting sysctl to original value ... ok Writing entire sysctl in single write ... ok Writing middle of sysctl after synchronized seek ... ok Writing beyond end of sysctl ... ok Writing sysctl with multiple long writes ... ok Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/Makefile | 1 tools/testing/selftests/sysctl/Makefile | 19 ++ tools/testing/selftests/sysctl/common_tests | 109 ++++++++++++++ tools/testing/selftests/sysctl/run_numerictests | 10 + tools/testing/selftests/sysctl/run_stringtests | 77 +++++++++ 5 files changed, 216 insertions(+) diff -puN tools/testing/selftests/Makefile~tools-testing-selftests-sysctl-validate-sysctl_writes_strict tools/testing/selftests/Makefile --- a/tools/testing/selftests/Makefile~tools-testing-selftests-sysctl-validate-sysctl_writes_strict +++ a/tools/testing/selftests/Makefile @@ -10,6 +10,7 @@ TARGETS += timers TARGETS += vm TARGETS += powerpc TARGETS += user +TARGETS += sysctl all: for TARGET in $(TARGETS); do \ diff -puN /dev/null tools/testing/selftests/sysctl/Makefile --- /dev/null +++ a/tools/testing/selftests/sysctl/Makefile @@ -0,0 +1,19 @@ +# Makefile for sysctl selftests. +# Expects kernel.sysctl_writes_strict=1. + +# No binaries, but make sure arg-less "make" doesn't trigger "run_tests". +all: + +# Allow specific tests to be selected. +test_num: + @/bin/sh ./run_numerictests + +test_string: + @/bin/sh ./run_stringtests + +run_tests: all test_num test_string + +# Nothing to clean up. +clean: + +.PHONY: all run_tests clean test_num test_string diff -puN /dev/null tools/testing/selftests/sysctl/common_tests --- /dev/null +++ a/tools/testing/selftests/sysctl/common_tests @@ -0,0 +1,109 @@ +#!/bin/sh + +TEST_FILE=$(mktemp) + +echo "== Testing sysctl behavior against ${TARGET} ==" + +set_orig() +{ + echo "${ORIG}" > "${TARGET}" +} + +set_test() +{ + echo "${TEST_STR}" > "${TARGET}" +} + +verify() +{ + local seen + seen=$(cat "$1") + if [ "${seen}" != "${TEST_STR}" ]; then + return 1 + fi + return 0 +} + +trap 'set_orig; rm -f "${TEST_FILE}"' EXIT + +rc=0 + +echo -n "Writing test file ... " +echo "${TEST_STR}" > "${TEST_FILE}" +if ! verify "${TEST_FILE}"; then + echo "FAIL" >&2 + exit 1 +else + echo "ok" +fi + +echo -n "Checking sysctl is not set to test value ... " +if verify "${TARGET}"; then + echo "FAIL" >&2 + exit 1 +else + echo "ok" +fi + +echo -n "Writing sysctl from shell ... " +set_test +if ! verify "${TARGET}"; then + echo "FAIL" >&2 + exit 1 +else + echo "ok" +fi + +echo -n "Resetting sysctl to original value ... " +set_orig +if verify "${TARGET}"; then + echo "FAIL" >&2 + exit 1 +else + echo "ok" +fi + +# Now that we've validated the sanity of "set_test" and "set_orig", +# we can use those functions to set starting states before running +# specific behavioral tests. + +echo -n "Writing entire sysctl in single write ... " +set_orig +dd if="${TEST_FILE}" of="${TARGET}" bs=4096 2>/dev/null +if ! verify "${TARGET}"; then + echo "FAIL" >&2 + rc=1 +else + echo "ok" +fi + +echo -n "Writing middle of sysctl after synchronized seek ... " +set_test +dd if="${TEST_FILE}" of="${TARGET}" bs=1 seek=1 skip=1 2>/dev/null +if ! verify "${TARGET}"; then + echo "FAIL" >&2 + rc=1 +else + echo "ok" +fi + +echo -n "Writing beyond end of sysctl ... " +set_orig +dd if="${TEST_FILE}" of="${TARGET}" bs=20 seek=2 2>/dev/null +if verify "${TARGET}"; then + echo "FAIL" >&2 + rc=1 +else + echo "ok" +fi + +echo -n "Writing sysctl with multiple long writes ... " +set_orig +(perl -e 'print "A" x 50;'; echo "${TEST_STR}") | \ + dd of="${TARGET}" bs=50 2>/dev/null +if verify "${TARGET}"; then + echo "FAIL" >&2 + rc=1 +else + echo "ok" +fi diff -puN /dev/null tools/testing/selftests/sysctl/run_numerictests --- /dev/null +++ a/tools/testing/selftests/sysctl/run_numerictests @@ -0,0 +1,10 @@ +#!/bin/sh + +SYSCTL="/proc/sys" +TARGET="${SYSCTL}/vm/swappiness" +ORIG=$(cat "${TARGET}") +TEST_STR=$(( $ORIG + 1 )) + +. ./common_tests + +exit $rc diff -puN /dev/null tools/testing/selftests/sysctl/run_stringtests --- /dev/null +++ a/tools/testing/selftests/sysctl/run_stringtests @@ -0,0 +1,77 @@ +#!/bin/sh + +SYSCTL="/proc/sys" +TARGET="${SYSCTL}/kernel/domainname" +ORIG=$(cat "${TARGET}") +TEST_STR="Testing sysctl" + +. ./common_tests + +# Only string sysctls support seeking/appending. +MAXLEN=65 + +echo -n "Writing entire sysctl in short writes ... " +set_orig +dd if="${TEST_FILE}" of="${TARGET}" bs=1 2>/dev/null +if ! verify "${TARGET}"; then + echo "FAIL" >&2 + rc=1 +else + echo "ok" +fi + +echo -n "Writing middle of sysctl after unsynchronized seek ... " +set_test +dd if="${TEST_FILE}" of="${TARGET}" bs=1 seek=1 2>/dev/null +if verify "${TARGET}"; then + echo "FAIL" >&2 + rc=1 +else + echo "ok" +fi + +echo -n "Checking sysctl maxlen is at least $MAXLEN ... " +set_orig +perl -e 'print "A" x ('"${MAXLEN}"'-2), "B";' | \ + dd of="${TARGET}" bs="${MAXLEN}" 2>/dev/null +if ! grep -q B "${TARGET}"; then + echo "FAIL" >&2 + rc=1 +else + echo "ok" +fi + +echo -n "Checking sysctl keeps original string on overflow append ... " +set_orig +perl -e 'print "A" x ('"${MAXLEN}"'-1), "B";' | \ + dd of="${TARGET}" bs=$(( MAXLEN - 1 )) 2>/dev/null +if grep -q B "${TARGET}"; then + echo "FAIL" >&2 + rc=1 +else + echo "ok" +fi + +echo -n "Checking sysctl stays NULL terminated on write ... " +set_orig +perl -e 'print "A" x ('"${MAXLEN}"'-1), "B";' | \ + dd of="${TARGET}" bs="${MAXLEN}" 2>/dev/null +if grep -q B "${TARGET}"; then + echo "FAIL" >&2 + rc=1 +else + echo "ok" +fi + +echo -n "Checking sysctl stays NULL terminated on overwrite ... " +set_orig +perl -e 'print "A" x ('"${MAXLEN}"'-1), "BB";' | \ + dd of="${TARGET}" bs=$(( $MAXLEN + 1 )) 2>/dev/null +if grep -q B "${TARGET}"; then + echo "FAIL" >&2 + rc=1 +else + echo "ok" +fi + +exit $rc _ Patches currently in -mm which might be from keescook@xxxxxxxxxxxx are lib-vsprintf-add-%pt-format-specifier.patch binfmt_elfc-use-get_random_int-to-fix-entropy-depleting.patch ptrace-fix-fork-event-messages-across-pid-namespaces.patch sysctl-clean-up-char-buffer-arguments.patch sysctl-refactor-sysctl-string-writing-logic.patch sysctl-allow-for-strict-write-position-handling.patch sysctl-allow-for-strict-write-position-handling-fix.patch tools-testing-selftests-sysctl-validate-sysctl_writes_strict.patch tools-testing-selftests-sysctl-validate-sysctl_writes_strict-fix.patch linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html