From c0f53628926e9fe8956ea276e30d98817d8cbcd4 Mon Sep 17 00:00:00 2001 From: Filipe Brandenburger Date: Wed, 10 Aug 2016 13:27:07 -0700 Subject: [PATCH] libmount: Preserve empty string value in optstr parsing Recent mount (since the switch to libmount in v2.22) drops the '=' in mount options that are set to an empty value. For example, the command line below will be affected: # mount -o rw,myopt='' -t tmpfs tmpfs /mnt/tmp Fix that by preserving an empty string in the options passed to the mount(2) syscall when they are present on the command line. Add test cases to ensure empty string handling is working as expected and in order to prevent regressions in the future. Also tested manually by stracing mount commands (on a kernel which accepts a special extra option, for testing purposes.) Before this commit: # strace -e mount ./mount -t tmpfs -o rw,myopt='' tmpfs /mnt/tmp mount("tmpfs", "/mnt/tmp", "tmpfs", MS_MGC_VAL, "myarg") = -1 EINVAL (Invalid argument) After this commit: # strace -e mount ./mount -t tmpfs -o rw,myopt='' tmpfs /mnt/tmp mount("tmpfs", "/mnt/tmp", "tmpfs", MS_MGC_VAL, "myopt=") = 0 All test cases pass, including newly added test cases. Also checked them with valgrind using: $ tests/run.sh --memcheck libmount/optstr Fixes #332. Signed-off-by: Filipe Brandenburger Signed-off-by: Karel Zak Upstream: http://github.com/karelzak/util-linux/commit/727c689908c5e68c92aa1dd65e0d3bdb6d91c1e5 Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1740572 --- libmount/src/optstr.c | 4 +-- .../libmount/optstr-append-empty-value | 1 + .../libmount/optstr-deduplicate-empty | 1 + .../libmount/optstr-prepend-empty-value | 1 + .../libmount/optstr-remove-empty-value | 1 + tests/expected/libmount/optstr-set-empty | 1 + tests/expected/libmount/optstr-set-new-empty | 1 + .../libmount/optstr-set-new-end-empty | 1 + tests/ts/libmount/optstr | 28 +++++++++++++++++++ 9 files changed, 37 insertions(+), 2 deletions(-) create mode 100644 tests/expected/libmount/optstr-append-empty-value create mode 100644 tests/expected/libmount/optstr-deduplicate-empty create mode 100644 tests/expected/libmount/optstr-prepend-empty-value create mode 100644 tests/expected/libmount/optstr-remove-empty-value create mode 100644 tests/expected/libmount/optstr-set-empty create mode 100644 tests/expected/libmount/optstr-set-new-empty create mode 100644 tests/expected/libmount/optstr-set-new-end-empty diff --git a/libmount/src/optstr.c b/libmount/src/optstr.c index 3c680ff6e..7bd9bbdb5 100644 --- a/libmount/src/optstr.c +++ b/libmount/src/optstr.c @@ -186,7 +186,7 @@ static int __mnt_optstr_append_option(char **optstr, sz = osz + nsz + 1; /* 1: '\0' */ if (osz) sz++; /* ',' options separator */ - if (vsz) + if (value) sz += vsz + 1; /* 1: '=' */ p = realloc(*optstr, sz); @@ -202,7 +202,7 @@ static int __mnt_optstr_append_option(char **optstr, memcpy(p, name, nsz); p += nsz; - if (vsz) { + if (value) { *p++ = '='; memcpy(p, value, vsz); p += vsz; diff --git a/tests/expected/libmount/optstr-append-empty-value b/tests/expected/libmount/optstr-append-empty-value new file mode 100644 index 000000000..35adf5c72 --- /dev/null +++ b/tests/expected/libmount/optstr-append-empty-value @@ -0,0 +1 @@ +result: >aaa,bbb=BBB,ccc,ddd=< diff --git a/tests/expected/libmount/optstr-deduplicate-empty b/tests/expected/libmount/optstr-deduplicate-empty new file mode 100644 index 000000000..63b74f678 --- /dev/null +++ b/tests/expected/libmount/optstr-deduplicate-empty @@ -0,0 +1 @@ +result: >bbb,ccc,xxx,ddd,AAA=,fff=eee< diff --git a/tests/expected/libmount/optstr-prepend-empty-value b/tests/expected/libmount/optstr-prepend-empty-value new file mode 100644 index 000000000..4cea63527 --- /dev/null +++ b/tests/expected/libmount/optstr-prepend-empty-value @@ -0,0 +1 @@ +result: >ddd=,aaa,bbb=BBB,ccc< diff --git a/tests/expected/libmount/optstr-remove-empty-value b/tests/expected/libmount/optstr-remove-empty-value new file mode 100644 index 000000000..eee5c95b9 --- /dev/null +++ b/tests/expected/libmount/optstr-remove-empty-value @@ -0,0 +1 @@ +result: >aaa,ccc< diff --git a/tests/expected/libmount/optstr-set-empty b/tests/expected/libmount/optstr-set-empty new file mode 100644 index 000000000..e0a3300f9 --- /dev/null +++ b/tests/expected/libmount/optstr-set-empty @@ -0,0 +1 @@ +result: >aaa,bbb=,ccc< diff --git a/tests/expected/libmount/optstr-set-new-empty b/tests/expected/libmount/optstr-set-new-empty new file mode 100644 index 000000000..a1cfb3721 --- /dev/null +++ b/tests/expected/libmount/optstr-set-new-empty @@ -0,0 +1 @@ +result: >aaa=,bbb=BBB,ccc< diff --git a/tests/expected/libmount/optstr-set-new-end-empty b/tests/expected/libmount/optstr-set-new-end-empty new file mode 100644 index 000000000..d0e9880f3 --- /dev/null +++ b/tests/expected/libmount/optstr-set-new-end-empty @@ -0,0 +1 @@ +result: >aaa,bbb=BBB,ccc=< diff --git a/tests/ts/libmount/optstr b/tests/ts/libmount/optstr index f6a5c0530..07a548963 100755 --- a/tests/ts/libmount/optstr +++ b/tests/ts/libmount/optstr @@ -20,6 +20,10 @@ ts_init_subtest "append-value" ts_valgrind $TESTPROG --append "aaa,bbb=BBB,ccc" "ddd" "DDD" &> $TS_OUTPUT ts_finalize_subtest +ts_init_subtest "append-empty-value" +ts_valgrind $TESTPROG --append "aaa,bbb=BBB,ccc" "ddd" "" &> $TS_OUTPUT +ts_finalize_subtest + ts_init_subtest "prepend" ts_valgrind $TESTPROG --prepend "aaa,bbb=BBB,ccc" "ddd" &> $TS_OUTPUT ts_finalize_subtest @@ -28,6 +32,10 @@ ts_init_subtest "prepend-value" ts_valgrind $TESTPROG --prepend "aaa,bbb=BBB,ccc" "ddd" "DDD" &> $TS_OUTPUT ts_finalize_subtest +ts_init_subtest "prepend-empty-value" +ts_valgrind $TESTPROG --prepend "aaa,bbb=BBB,ccc" "ddd" "" &> $TS_OUTPUT +ts_finalize_subtest + ts_init_subtest "set-remove" ts_valgrind $TESTPROG --set "aaa,bbb=BBB,ccc" "bbb" &> $TS_OUTPUT ts_finalize_subtest @@ -40,14 +48,26 @@ ts_init_subtest "set-large" ts_valgrind $TESTPROG --set "aaa,bbb=BBB,ccc" "bbb" "XXX-YYY-ZZZ" &> $TS_OUTPUT ts_finalize_subtest +ts_init_subtest "set-empty" +ts_valgrind $TESTPROG --set "aaa,bbb=BBB,ccc" "bbb" "" &> $TS_OUTPUT +ts_finalize_subtest + ts_init_subtest "set-new" ts_valgrind $TESTPROG --set "aaa,bbb=BBB,ccc" "aaa" "XXX" &> $TS_OUTPUT ts_finalize_subtest +ts_init_subtest "set-new-empty" +ts_valgrind $TESTPROG --set "aaa,bbb=BBB,ccc" "aaa" "" &> $TS_OUTPUT +ts_finalize_subtest + ts_init_subtest "set-new-end" ts_valgrind $TESTPROG --set "aaa,bbb=BBB,ccc" "ccc" "XXX" &> $TS_OUTPUT ts_finalize_subtest +ts_init_subtest "set-new-end-empty" +ts_valgrind $TESTPROG --set "aaa,bbb=BBB,ccc" "ccc" "" &> $TS_OUTPUT +ts_finalize_subtest + ts_init_subtest "get" ts_valgrind $TESTPROG --get "aaa,bbb=BBB,ccc" "aaa" &> $TS_OUTPUT ts_finalize_subtest @@ -68,6 +88,10 @@ ts_init_subtest "remove-value" ts_valgrind $TESTPROG --remove "aaa,bbb=BBB,ccc" "bbb" &> $TS_OUTPUT ts_finalize_subtest +ts_init_subtest "remove-empty-value" +ts_valgrind $TESTPROG --remove "aaa,bbb=,ccc" "bbb" &> $TS_OUTPUT +ts_finalize_subtest + ts_init_subtest "split" ts_valgrind $TESTPROG --split "aaa,bbb=BBB,ccc,x-bar,x-foo=foodata,user=kzak,noexec,nosuid,loop=/dev/loop0" &> $TS_OUTPUT ts_finalize_subtest @@ -92,4 +116,8 @@ ts_init_subtest "deduplicate" ts_valgrind $TESTPROG --dedup bbb,ccc,AAA,xxx,AAA=a,AAA=bbb,ddd,AAA=ccc,fff=eee AAA &> $TS_OUTPUT ts_finalize_subtest +ts_init_subtest "deduplicate-empty" +ts_valgrind $TESTPROG --dedup bbb,ccc,AAA,xxx,AAA=a,AAA=bbb,ddd,AAA=,fff=eee AAA &> $TS_OUTPUT +ts_finalize_subtest + ts_finalize -- 2.21.0