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samba-mirror/source3/script/tests/test_symlink_traversal_smb1_posix.sh
Jeremy Allison 5075df4575 s3: smbd: Remove ugly SMB1-specific hack to filename_convert_dirfsp()
This was added due to the error code check in test_symlink_traversal_smb1_posix.sh.
After careful consideration I've realized the error code expected here
is incorrect, and not providing any security benefit.

We already check that trying to fetch a file/traverse through a
symlink that points outside of a share returns NT_STATUS_OBJECT_PATH_NOT_FOUND,
and this is enforced in the symlink checks already inside filename_convert_dirfsp().

If a symlink points to a directory within the share for which
the user has no permissions (as is tested here), then there's no
benefit in mapping the error code from NT_STATUS_ACCESS_DENIED
to NT_STATUS_OBJECT_PATH_NOT_FOUND, as we are not providing any
extra information about the filesystem state the user cannot already
obtain by normal SMB1+POSIX calls.

Change the error code expected in this single test from NT_STATUS_OBJECT_PATH_NOT_FOUND
to NT_STATUS_ACCESS_DENIED.

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>

Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Fri Aug  5 10:24:23 UTC 2022 on sn-devel-184
2022-08-05 10:24:22 +00:00

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#!/bin/sh
if [ $# -lt 7 ]; then
cat <<EOF
Usage: test_symlink_traversal_smb1_posix.sh SERVER SERVER_IP USERNAME PASSWORD LOCAL_PATH PREFIX SMBCLIENT
EOF
exit 1
fi
SERVER="${1}"
SERVER_IP="${2}"
USERNAME="${3}"
PASSWORD="${4}"
LOCAL_PATH="${5}"
PREFIX="${6}"
SMBCLIENT="${7}"
SMBCLIENT="$VALGRIND ${SMBCLIENT}"
shift 6
incdir=$(dirname "$0")/../../../testprogs/blackbox
. "$incdir"/subunit.sh
failed=0
# Do not let deprecated option warnings muck this up
SAMBA_DEPRECATED_SUPPRESS=1
export SAMBA_DEPRECATED_SUPPRESS
# Define the test environment/filenames.
#
share_test_dir="$LOCAL_PATH"
#
# These files/directories will be created.
#
file_outside_share="/tmp/symlink_traverse_test_file.$$"
dir_outside_share="/tmp/symlink_traverse_test_dir.$$"
file_outside_share_noperms="/tmp/symlink_traverse_test_file_noperm.$$"
dir_outside_share_noperms="/tmp/symlink_traverse_test_dir_noperm.$$"
#
# These two objects do not exist.
#
file_outside_share_noexist="/tmp/symlink_traverse_test_noexist.$$"
dir_outside_share_noexist="/tmp/symlink_traverse_test_dir_noexist.$$"
#
# Cleanup function.
#
do_cleanup()
{
(
#subshell.
cd "$share_test_dir" || return
rm -f "file_exists"
rm -f "symlink_noexist"
rm -f "symlink_file_outside_share"
rm -f "symlink_file_outside_share_noexist"
rm -f "symlink_dir_outside_share"
rm -f "symlink_dir_outside_share_noexist"
rm -f "symlink_file_outside_share_noperms"
rm -f "symlink_dir_outside_share_noperms"
rm -rf "emptydir"
# Links inside share.
rm -f "symlink_file_inside_share_noperms"
rm -f "file_inside_share_noperms"
rm -f "symlink_dir_inside_share_noperms"
chmod 755 "dir_inside_share_noperms"
rm -rf "dir_inside_share_noperms"
)
rm -f "$file_outside_share"
rm -rf "$dir_outside_share"
rm -f "$file_outside_share_noperms"
rm -rf "$dir_outside_share_noperms"
}
#
# Ensure we start from a clean slate.
#
do_cleanup
#
# Create the test files/directories/symlinks.
#
# File/directory explicitly outside share.
touch "$file_outside_share"
mkdir "$dir_outside_share"
# File/directory explicitly outside share with permission denied.
touch "$file_outside_share_noperms"
chmod 0 "$file_outside_share_noperms"
mkdir "$dir_outside_share_noperms"
chmod 0 "$dir_outside_share_noperms"
#
# Create links to these objects inside the share definition.
(
#subshell.
cd "$share_test_dir" || return
touch "file_exists"
ln -s "noexist" "symlink_noexist"
ln -s "$file_outside_share" "symlink_file_outside_share"
ln -s "$file_outside_share_noexist" "symlink_file_outside_share_noexist"
ln -s "$dir_outside_share" "symlink_dir_outside_share"
ln -s "$dir_outside_share_noexist" "symlink_dir_outside_share_noexist"
ln -s "$file_outside_share_noperms" "symlink_file_outside_share_noperms"
ln -s "$dir_outside_share_noperms" "symlink_dir_outside_share_noperms"
#
# Create the identical symlink set underneath "emptydir"
mkdir "emptydir"
(
#subshell
cd "emptydir" || return
touch "file_exists"
ln -s "noexist" "symlink_noexist"
ln -s "$file_outside_share" "symlink_file_outside_share"
ln -s "$file_outside_share_noexist" "symlink_file_outside_share_noexist"
ln -s "$dir_outside_share" "symlink_dir_outside_share"
ln -s "$dir_outside_share_noexist" "symlink_dir_outside_share_noexist"
ln -s "$file_outside_share_noperms" "symlink_file_outside_share_noperms"
ln -s "$dir_outside_share_noperms" "symlink_dir_outside_share_noperms"
)
#
# Create symlinks to access denied file and directory
# objects within the share
touch "file_inside_share_noperms"
chmod 0 "file_inside_share_noperms"
ln -s "file_inside_share_noperms" "symlink_file_inside_share_noperms"
mkdir "dir_inside_share_noperms"
touch "dir_inside_share_noperms/noperm_file_exists"
chmod 0 "dir_inside_share_noperms"
ln -s "dir_inside_share_noperms" "symlink_dir_inside_share_noperms"
)
#
# smbclient function given command, path, expected error, and posix.
#
smbclient_expect_error()
{
filecmd="$1"
filename1="$2"
filename2="$3"
expected_error="$4"
tmpfile=$PREFIX/smbclient_interactive_prompt_commands
cat >"$tmpfile" <<EOF
posix
$filecmd $filename1 $filename2
quit
EOF
cmd='CLI_FORCE_INTERACTIVE=yes $SMBCLIENT -U$USERNAME%$PASSWORD //$SERVER/local_symlinks -I$SERVER_IP -mNT1 < $tmpfile 2>&1'
eval echo "$cmd"
out=$(eval "$cmd")
ret=$?
rm -f "$tmpfile"
if [ $ret != 0 ]; then
printf "%s\n" "$out"
printf "failed accessing local_symlinks with error %s\n" "$ret"
return 1
fi
if [ "$expected_error" = "NT_STATUS_OK" ]; then
printf "%s" "$out" | grep -v "NT_STATUS_"
else
printf "%s" "$out" | grep "$expected_error"
fi
ret=$?
if [ $ret != 0 ]; then
printf "%s\n" "$out"
printf "failed - should get %s doing posix \"%s %s %s\"\n" "$expected_error" "$filecmd" "$filename1" "$filename2"
return 1
fi
}
#
# SMB1+posix tests.
#
test_symlink_traversal_SMB1_posix_onename()
{
name="$1"
do_rename="$2"
#
# get commands.
#
# Remember in SMB1+POSIX, "*" is a perfectly valid pathname component,
# and symlinks can be seen, but not necessarily followed.
#
smbclient_expect_error "get" "$name" "" "NT_STATUS_OBJECT_NAME_NOT_FOUND" || return 1
smbclient_expect_error "get" "$name/noexist" "" "NT_STATUS_OBJECT_PATH_NOT_FOUND" || return 1
smbclient_expect_error "get" "$name/*" "" "NT_STATUS_OBJECT_PATH_NOT_FOUND" || return 1
smbclient_expect_error "get" "$name/*/noexist" "" "NT_STATUS_OBJECT_PATH_NOT_FOUND" || return 1
# Now in subdirectory emptydir
smbclient_expect_error "get" "emptydir/$name" "" "NT_STATUS_OBJECT_NAME_NOT_FOUND" || return 1
smbclient_expect_error "get" "emptydir/$name/noexist" "" "NT_STATUS_OBJECT_PATH_NOT_FOUND" || return 1
smbclient_expect_error "get" "emptydir/$name/*" "" "NT_STATUS_OBJECT_PATH_NOT_FOUND" || return 1
smbclient_expect_error "get" "emptydir/$name/*/noexist" "" "NT_STATUS_OBJECT_PATH_NOT_FOUND" || return 1
#
# ls commands.
#
smbclient_expect_error "ls" "$name" "" "NT_STATUS_OK" || return 1
smbclient_expect_error "ls" "$name/noexist" "" "NT_STATUS_NOT_A_DIRECTORY" || return 1
smbclient_expect_error "ls" "$name/*" "" "NT_STATUS_NOT_A_DIRECTORY" || return 1
smbclient_expect_error "ls" "$name/*/noexist" "" "NT_STATUS_OBJECT_PATH_NOT_FOUND" || return 1
# Now in subdirectory emptydir
smbclient_expect_error "ls" "emptydir/$name" "" "NT_STATUS_OK" || return 1
smbclient_expect_error "ls" "emptydir/$name/noexist" "" "NT_STATUS_NOT_A_DIRECTORY" || return 1
smbclient_expect_error "ls" "emptydir/$name/*" "" "NT_STATUS_NOT_A_DIRECTORY" || return 1
smbclient_expect_error "ls" "emptydir/$name/*/noexist" "" "NT_STATUS_OBJECT_PATH_NOT_FOUND" || return 1
#
# SMB1+POSIX stat commands. All symlinks can be stat'ed.
#
smbclient_expect_error "stat" "$name" "" "NT_STATUS_OK" || return 1
smbclient_expect_error "stat" "emptydir/$name" "" "NT_STATUS_OK" || return 1
#
# del commands. Under SMB1+POSIX we can legitimately delete symlinks, so don't
# try and delete symlink targets, we need them for the later tests.
#
smbclient_expect_error "del" "$name/noexist" "" "NT_STATUS_NOT_A_DIRECTORY" || return 1
# Now in subdirectory emptydir
smbclient_expect_error "del" "emptydir/$name/noexist" "" "NT_STATUS_NOT_A_DIRECTORY" || return 1
if [ "$do_rename" = "do rename" ]; then
#
# rename commands. Under SMB1+POSIX we can legitimately rename symlinks, so don't
# try and rename symlink targets, we need them for the later tests.
#
smbclient_expect_error "rename" "file_exists" "$name/noexist" "NT_STATUS_OBJECT_PATH_NOT_FOUND" || return 1
# Now in subdirectory emptydir
smbclient_expect_error "rename" "file_exists" "emptydir/$name/noexist" "NT_STATUS_OBJECT_PATH_NOT_FOUND" || return 1
fi
return 0
}
#
# Check error code returns traversing through different
# kinds of symlinks over SMB1+posix.
#
test_symlink_traversal_SMB1_posix()
{
test_symlink_traversal_SMB1_posix_onename "symlink_noexist" "no rename" || return 1
test_symlink_traversal_SMB1_posix_onename "symlink_file_outside_share" "do rename" || return 1
test_symlink_traversal_SMB1_posix_onename "symlink_dir_outside_share" "do rename" || return 1
test_symlink_traversal_SMB1_posix_onename "symlink_dir_outside_share_noexist" "no rename" || return 1
test_symlink_traversal_SMB1_posix_onename "symlink_file_outside_share_noperms" "do rename" || return 1
test_symlink_traversal_SMB1_posix_onename "symlink_dir_outside_share_noperms" "do rename" || return 1
#
# Test paths within share with no permissions.
#
# Can't 'get' file with no perms.
smbclient_expect_error "get" "file_inside_share_noperms" "" "NT_STATUS_ACCESS_DENIED" || return 1
# In SMB1+POSIX you can't "get" a symlink at all.
smbclient_expect_error "get" "symlink_file_inside_share_noperms" "" "NT_STATUS_OBJECT_NAME_NOT_FOUND" || return 1
# But can list it and the symlink to it.
smbclient_expect_error "ls" "file_inside_share_noperms" "" "NT_STATUS_OK" || return 1
smbclient_expect_error "ls" "symlink_file_inside_share_noperms" "" "NT_STATUS_OK" || return 1
# Can't 'get' file inside a directory with no perms.
smbclient_expect_error "get" "dir_inside_share_noperms/noperm_file_exists" "" "NT_STATUS_ACCESS_DENIED" || return 1
# In SMB1+POSIX you can't traverse through a symlink that points to a noperm directory.
smbclient_expect_error "get" "symlink_dir_inside_share_noperms/noperm_file_exists" "" "NT_STATUS_ACCESS_DENIED" || return 1
# But can list the directory with no perms and the symlink to it.
smbclient_expect_error "ls" "dir_inside_share_noperms" "" "NT_STATUS_OK" || return 1
smbclient_expect_error "ls" "symlink_dir_inside_share_noperms" "" "NT_STATUS_OK" || return 1
}
testit "symlink_traversal_SMB1_posix" \
test_symlink_traversal_SMB1_posix ||
failed=$((failed + 1))
#
# Cleanup.
do_cleanup
testok "$0" "$failed"