From: Eric Biggers <ebiggers@xxxxxxxxxx>
_fsv_have_hash_algorithm() uses _fsv_enable() without a signature, so it
always fails when called while fs.verity.require_signatures=1. This
happens in generic/577, which tests file signing. This wasn't noticed
because it just made part of generic/577 always be skipped.
Fix this by making _fsv_have_hash_algorithm() temporarily set
fs.verity.require_signatures to 0.
Since the previous value needs to be restored afterwards, whether it is
0 or 1, also make some changes to the fs.verity.require_signatures
helper functions to allow the restoration of the previous value, rather
than the value that existed at the beginning of the test.
Finally, make a couple related cleanups: make _fsv_have_hash_algorithm()
always delete the file it works with, and also update the similar code
in _require_scratch_verity().
Reported-by: Andrey Albershteyn <aalbersh@xxxxxxxxxx>
Reviewed-by: Andrey Albershteyn <aalbersh@xxxxxxxxxx>
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
common/verity | 58 ++++++++++++++++++++++++++++++++-------------------
1 file changed, 37 insertions(+), 21 deletions(-)
diff --git a/common/verity b/common/verity
index 65a39d3e..f98dcb07 100644
--- a/common/verity
+++ b/common/verity
@@ -44,12 +44,13 @@ _require_scratch_verity()
# doesn't work on ext3-style filesystems. So, try actually using it.
echo foo > $SCRATCH_MNT/tmpfile
_disable_fsverity_signatures
- if ! _fsv_enable $SCRATCH_MNT/tmpfile; then
- _restore_fsverity_signatures
+ _fsv_enable $SCRATCH_MNT/tmpfile
+ local status=$?
+ _restore_prev_fsverity_signatures
+ rm -f $SCRATCH_MNT/tmpfile
+ if (( $status != 0 )); then
_notrun "$FSTYP verity isn't usable by default with these mkfs options"
fi
- _restore_fsverity_signatures
- rm -f $SCRATCH_MNT/tmpfile
_scratch_unmount
@@ -105,10 +106,7 @@ _fsv_load_cert()
_disable_fsverity_signatures()
{
if [ -e /proc/sys/fs/verity/require_signatures ]; then
- if [ -z "$FSVERITY_SIG_CTL_ORIG" ]; then
- FSVERITY_SIG_CTL_ORIG=$(</proc/sys/fs/verity/require_signatures)
- fi
- echo 0 > /proc/sys/fs/verity/require_signatures
+ _set_fsverity_require_signatures 0
fi
}
@@ -116,18 +114,36 @@ _disable_fsverity_signatures()
# This assumes that _require_fsverity_builtin_signatures() was called.
_enable_fsverity_signatures()
{
- if [ -z "$FSVERITY_SIG_CTL_ORIG" ]; then
- FSVERITY_SIG_CTL_ORIG=$(</proc/sys/fs/verity/require_signatures)
- fi
- echo 1 > /proc/sys/fs/verity/require_signatures
+ _set_fsverity_require_signatures 1
}
-# Restore the original signature verification setting.
+# Restore the original value of fs.verity.require_signatures, i.e. the value it
+# had at the beginning of the test.
_restore_fsverity_signatures()
{
- if [ -n "$FSVERITY_SIG_CTL_ORIG" ]; then
- echo "$FSVERITY_SIG_CTL_ORIG" > /proc/sys/fs/verity/require_signatures
- fi
+ if [ -n "$FSVERITY_SIG_CTL_ORIG" ]; then
+ _set_fsverity_require_signatures "$FSVERITY_SIG_CTL_ORIG"
+ fi
+}
+
+# Restore the previous value of fs.verity.require_signatures, i.e. the value it
+# had just before it was last written to.
+_restore_prev_fsverity_signatures()
+{
+ if [ -n "$FSVERITY_SIG_CTL_PREV" ]; then
+ _set_fsverity_require_signatures "$FSVERITY_SIG_CTL_PREV"
+ fi
+}
+
+_set_fsverity_require_signatures()
+{
+ local newval=$1
+ local oldval=$(</proc/sys/fs/verity/require_signatures)
+ FSVERITY_SIG_CTL_PREV=$oldval
+ if [ -z "$FSVERITY_SIG_CTL_ORIG" ]; then
+ FSVERITY_SIG_CTL_ORIG=$oldval
+ fi
+ echo "$newval" > /proc/sys/fs/verity/require_signatures
}
# Require userspace and kernel support for 'fsverity dump_metadata'.
@@ -245,14 +261,14 @@ _fsv_have_hash_algorithm()
local hash_alg=$1
local test_file=$2
+ _disable_fsverity_signatures
rm -f $test_file
head -c 4096 /dev/zero > $test_file
- if ! _fsv_enable --hash-alg=$hash_alg $test_file &>> $seqres.full; then
- # no kernel support
- return 1
- fi
+ _fsv_enable --hash-alg=$hash_alg $test_file &>> $seqres.full
+ local status=$?
+ _restore_prev_fsverity_signatures
rm -f $test_file
- return 0
+ return $status
}
#
--
2.38.1
