From patchwork Fri Nov 19 19:42:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 12629427 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9D63C433EF for ; Fri, 19 Nov 2021 19:42:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B2EFD61AFB for ; Fri, 19 Nov 2021 19:42:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229879AbhKSTpa (ORCPT ); Fri, 19 Nov 2021 14:45:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:45068 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236017AbhKSTp3 (ORCPT ); Fri, 19 Nov 2021 14:45:29 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 349D261546; Fri, 19 Nov 2021 19:42:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637350947; bh=AhYodmabytFoUCncFCT++WKrXyC0HAMLyTSVxEbwq/c=; h=From:To:Cc:Subject:Date:From; b=t4AXpnYGXH+zt7F/P723Q7eKDqe+WJWvB40n3qXQ3lG+I0RWJLWlkddvfrOlZvURC WbQAuZ85Ar7KJu/6g9RxEBjFxDIVcQbjF4YYgJn4GB9vSKY1puvQxTNh25EAT0TLKa ObNbuLpnLG32s87fhHo68qHZeZCVKl0DjTRADOO7REv5n0qnEfivq4S8Jk23iwetkR EKYJa4KseMSvtHLhef6r11VbXq2//WV0WBPhRJVpWtaZvq2UR54kOvpIZI9R6OCf09 X9r/eflLp5n/e4ZgmDJ06sgz6cNWyi7KLeLIY/Uh9LXg06a/MI1y+CQJzdFuzcH/Mx jaI2YAQzIRWrA== From: Christian Brauner To: Eryu Guan Cc: Seth Forshee , Christoph Hellwig , fstests@vger.kernel.org, Christian Brauner Subject: [PATCH v2] generic: test circular mappings Date: Fri, 19 Nov 2021 20:42:09 +0100 Message-Id: <20211119194209.2997413-1-brauner@kernel.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=22089; h=from:subject; bh=OrhkSDYn5WWcoZ67mGG4az3Re02LlbnnDrrmnFSHY9A=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMSRO//vt4WGe05asD26e21ZjXlr66MIt/+tuUj1C3KftN+rX LS0O6ChlYRDjYpAVU2RxaDcJl1vOU7HZKFMDZg4rE8gQBi5OAZiIdS3D/8ps+cAtXx7xq2zUeHCFxe vh2nXR7aElgaqxW4ueLZ79+RbDf7+k6ZFl55ynz/y4WyOuc2p5vjrbj8X/xZIk47jzls2tYgUA X-Developer-Key: i=christian.brauner@ubuntu.com; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Precedence: bulk List-ID: X-Mailing-List: fstests@vger.kernel.org From: Christian Brauner This is a regression test for the fix in [1]. The test makes sure that setattr behaves correctly on idmapped mounts that make use of circular mappings. Such mappings may e.g. be used to allow two users to share home directories through the same idmapped mount. The tests are explained in detail in code comments. [1]: commit 968219708108 ("fs: handle circular mappings correctly") Cc: Seth Forshee Cc: Eryu Guan Cc: Christoph Hellwig Cc: fstests@vger.kernel.org Signed-off-by: Christian Brauner --- /* v2 */ - Eryu Guan : - ensure fsqga and fsqga2 user and group are included in test requirements - include commit that fixes the bug in commit log and commit message --- src/idmapped-mounts/idmapped-mounts.c | 482 ++++++++++++++++++++++++-- src/idmapped-mounts/utils.c | 43 ++- tests/generic/651 | 33 ++ tests/generic/651.out | 2 + 4 files changed, 534 insertions(+), 26 deletions(-) create mode 100755 tests/generic/651 create mode 100644 tests/generic/651.out base-commit: bae1d15f6421cbe99b3e2e134c39d50248e7c261 diff --git a/src/idmapped-mounts/idmapped-mounts.c b/src/idmapped-mounts/idmapped-mounts.c index 83b7c89a..da690779 100644 --- a/src/idmapped-mounts/idmapped-mounts.c +++ b/src/idmapped-mounts/idmapped-mounts.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -409,6 +410,23 @@ static inline bool switch_fsids(uid_t fsuid, gid_t fsgid) return true; } +static inline bool switch_resids(uid_t uid, gid_t gid) +{ + if (setresgid(gid, gid, gid)) + return log_errno(false, "failure: setregid"); + + if (setresuid(uid, uid, uid)) + return log_errno(false, "failure: setresuid"); + + if (setfsgid(-1) != gid) + return log_errno(false, "failure: setfsgid(-1)"); + + if (setfsuid(-1) != uid) + return log_errno(false, "failure: setfsuid(-1)"); + + return true; +} + static inline bool switch_userns(int fd, uid_t uid, gid_t gid, bool drop_caps) { if (setns(fd, CLONE_NEWUSER)) @@ -636,6 +654,11 @@ __attribute__((unused)) static int print_r(int fd, const char *path) return ret; } +#else +__attribute__((unused)) static int print_r(int fd, const char *path) +{ + return 0; +} #endif /* fd_to_fd - transfer data from one fd to another */ @@ -13325,40 +13348,437 @@ out: return fret; } +#define USER1 "fsgqa" +#define USER2 "fsgqa2" + +/** + * lookup_ids - lookup uid and gid for a username + * @name: [in] name of the user + * @uid: [out] pointer to the user-ID + * @gid: [out] pointer to the group-ID + * + * Lookup the uid and gid of a user. + * + * Return: On success, true is returned. + * On error, false is returned. + */ +static bool lookup_ids(const char *name, uid_t *uid, gid_t *gid) +{ + bool bret = false; + struct passwd *pwentp = NULL; + struct passwd pwent; + char *buf; + ssize_t bufsize; + int ret; + + bufsize = sysconf(_SC_GETPW_R_SIZE_MAX); + if (bufsize < 0) + bufsize = 1024; + + buf = malloc(bufsize); + if (!buf) + return bret; + + ret = getpwnam_r(name, &pwent, buf, bufsize, &pwentp); + if (!ret && pwentp) { + *uid = pwent.pw_uid; + *gid = pwent.pw_gid; + bret = true; + } + + free(buf); + return bret; +} + +/** + * setattr_fix_968219708108 - test for commit 968219708108 ("fs: handle circular mappings correctly") + * + * Test that ->setattr() works correctly for idmapped mounts with circular + * idmappings such as: + * + * b:1000:1001:1 + * b:1001:1000:1 + * + * Assume a directory /source with two files: + * + * /source/file1 | 1000:1000 + * /source/file2 | 1001:1001 + * + * and we create an idmapped mount of /source at /target with an idmapped of: + * + * mnt_userns: 1000:1001:1 + * 1001:1000:1 + * + * In the idmapped mount file1 will be owned by uid 1001 and file2 by uid 1000: + * + * /target/file1 | 1001:1001 + * /target/file2 | 1000:1000 + * + * Because in essence the idmapped mount switches ownership for {g,u}id 1000 + * and {g,u}id 1001. + * + * 1. A user with fs{g,u}id 1000 must be allowed to setattr /target/file2 from + * {g,u}id 1000 in the idmapped mount to {g,u}id 1000. + * 2. A user with fs{g,u}id 1001 must be allowed to setattr /target/file1 from + * {g,u}id 1001 in the idmapped mount to {g,u}id 1001. + * 3. A user with fs{g,u}id 1000 must fail to setattr /target/file1 from + * {g,u}id 1001 in the idmapped mount to {g,u}id 1000. + * This must fail with EPERM. The caller's fs{g,u}id doesn't match the + * {g,u}id of the file. + * 4. A user with fs{g,u}id 1001 must fail to setattr /target/file2 from + * {g,u}id 1000 in the idmapped mount to {g,u}id 1000. + * This must fail with EPERM. The caller's fs{g,u}id doesn't match the + * {g,u}id of the file. + * 5. Both, a user with fs{g,u}id 1000 and a user with fs{g,u}id 1001, must + * fail to setattr /target/file1 owned by {g,u}id 1001 in the idmapped mount + * and /target/file2 owned by {g,u}id 1000 in the idmapped mount to any + * {g,u}id apart from {g,u}id 1000 or 1001 with EINVAL. + * Only {g,u}id 1000 and 1001 have a mapping in the idmapped mount. Other + * {g,u}id are unmapped. + */ +static int setattr_fix_968219708108(void) +{ + int fret = -1; + int open_tree_fd = -EBADF; + struct mount_attr attr = { + .attr_set = MOUNT_ATTR_IDMAP, + .userns_fd = -EBADF, + }; + int ret; + uid_t user1_uid, user2_uid; + gid_t user1_gid, user2_gid; + pid_t pid; + struct list idmap; + struct list *it_cur, *it_next; + + if (!caps_supported()) + return 0; + + list_init(&idmap); + + if (!lookup_ids(USER1, &user1_uid, &user1_gid)) { + log_stderr("failure: lookup_user"); + goto out; + } + + if (!lookup_ids(USER2, &user2_uid, &user2_gid)) { + log_stderr("failure: lookup_user"); + goto out; + } + + log_debug("Found " USER1 " with uid(%d) and gid(%d) and " USER2 " with uid(%d) and gid(%d)", + user1_uid, user1_gid, user2_uid, user2_gid); + + if (mkdirat(t_dir1_fd, DIR1, 0777)) { + log_stderr("failure: mkdirat"); + goto out; + } + + if (mknodat(t_dir1_fd, DIR1 "/" FILE1, S_IFREG | 0644, 0)) { + log_stderr("failure: mknodat"); + goto out; + } + + if (chown_r(t_mnt_fd, T_DIR1, user1_uid, user1_gid)) { + log_stderr("failure: chown_r"); + goto out; + } + + if (mknodat(t_dir1_fd, DIR1 "/" FILE2, S_IFREG | 0644, 0)) { + log_stderr("failure: mknodat"); + goto out; + } + + if (fchownat(t_dir1_fd, DIR1 "/" FILE2, user2_uid, user2_gid, AT_SYMLINK_NOFOLLOW)) { + log_stderr("failure: fchownat"); + goto out; + } + + print_r(t_mnt_fd, T_DIR1); + + /* u:1000:1001:1 */ + ret = add_map_entry(&idmap, user1_uid, user2_uid, 1, ID_TYPE_UID); + if (ret) { + log_stderr("failure: add_map_entry"); + goto out; + } + + /* u:1001:1000:1 */ + ret = add_map_entry(&idmap, user2_uid, user1_uid, 1, ID_TYPE_UID); + if (ret) { + log_stderr("failure: add_map_entry"); + goto out; + } + + /* g:1000:1001:1 */ + ret = add_map_entry(&idmap, user1_gid, user2_gid, 1, ID_TYPE_GID); + if (ret) { + log_stderr("failure: add_map_entry"); + goto out; + } + + /* g:1001:1000:1 */ + ret = add_map_entry(&idmap, user2_gid, user1_gid, 1, ID_TYPE_GID); + if (ret) { + log_stderr("failure: add_map_entry"); + goto out; + } + + attr.userns_fd = get_userns_fd_from_idmap(&idmap); + if (attr.userns_fd < 0) { + log_stderr("failure: get_userns_fd"); + goto out; + } + + open_tree_fd = sys_open_tree(t_dir1_fd, DIR1, + AT_NO_AUTOMOUNT | + AT_SYMLINK_NOFOLLOW | + OPEN_TREE_CLOEXEC | + OPEN_TREE_CLONE | + AT_RECURSIVE); + if (open_tree_fd < 0) { + log_stderr("failure: sys_open_tree"); + goto out; + } + + if (sys_mount_setattr(open_tree_fd, "", AT_EMPTY_PATH, &attr, sizeof(attr))) { + log_stderr("failure: sys_mount_setattr"); + goto out; + } + + print_r(open_tree_fd, ""); + + pid = fork(); + if (pid < 0) { + log_stderr("failure: fork"); + goto out; + } + if (pid == 0) { + /* switch to {g,u}id 1001 */ + if (!switch_resids(user2_uid, user2_gid)) + die("failure: switch_resids"); + + /* drop all capabilities */ + if (!caps_down()) + die("failure: caps_down"); + + /* + * The {g,u}id 0 is not mapped in this idmapped mount so this + * needs to fail with EINVAL. + */ + if (!fchownat(open_tree_fd, FILE1, 0, 0, AT_SYMLINK_NOFOLLOW)) + die("failure: change ownership"); + if (errno != EINVAL) + die("failure: errno"); + + /* + * A user with fs{g,u}id 1001 must be allowed to change + * ownership of /target/file1 owned by {g,u}id 1001 in this + * idmapped mount to {g,u}id 1001. + */ + if (fchownat(open_tree_fd, FILE1, user2_uid, user2_gid, + AT_SYMLINK_NOFOLLOW)) + die("failure: change ownership"); + + /* Verify that the ownership is still {g,u}id 1001. */ + if (!expected_uid_gid(open_tree_fd, FILE1, AT_SYMLINK_NOFOLLOW, + user2_uid, user2_gid)) + die("failure: check ownership"); + + /* + * A user with fs{g,u}id 1001 must not be allowed to change + * ownership of /target/file1 owned by {g,u}id 1001 in this + * idmapped mount to {g,u}id 1000. + */ + if (!fchownat(open_tree_fd, FILE1, user1_uid, user1_gid, + AT_SYMLINK_NOFOLLOW)) + die("failure: change ownership"); + if (errno != EPERM) + die("failure: errno"); + + /* Verify that the ownership is still {g,u}id 1001. */ + if (!expected_uid_gid(open_tree_fd, FILE1, AT_SYMLINK_NOFOLLOW, + user2_uid, user2_gid)) + die("failure: check ownership"); + + /* + * A user with fs{g,u}id 1001 must not be allowed to change + * ownership of /target/file2 owned by {g,u}id 1000 in this + * idmapped mount to {g,u}id 1000. + */ + if (!fchownat(open_tree_fd, FILE2, user1_uid, user1_gid, + AT_SYMLINK_NOFOLLOW)) + die("failure: change ownership"); + if (errno != EPERM) + die("failure: errno"); + + /* Verify that the ownership is still {g,u}id 1000. */ + if (!expected_uid_gid(open_tree_fd, FILE2, AT_SYMLINK_NOFOLLOW, + user1_uid, user1_gid)) + die("failure: check ownership"); + + /* + * A user with fs{g,u}id 1001 must not be allowed to change + * ownership of /target/file2 owned by {g,u}id 1000 in this + * idmapped mount to {g,u}id 1001. + */ + if (!fchownat(open_tree_fd, FILE2, user2_uid, user2_gid, + AT_SYMLINK_NOFOLLOW)) + die("failure: change ownership"); + if (errno != EPERM) + die("failure: errno"); + + /* Verify that the ownership is still {g,u}id 1000. */ + if (!expected_uid_gid(open_tree_fd, FILE2, AT_SYMLINK_NOFOLLOW, + user1_uid, user1_gid)) + die("failure: check ownership"); + + exit(EXIT_SUCCESS); + } + if (wait_for_pid(pid)) + goto out; + + pid = fork(); + if (pid < 0) { + log_stderr("failure: fork"); + goto out; + } + if (pid == 0) { + /* switch to {g,u}id 1000 */ + if (!switch_resids(user1_uid, user1_gid)) + die("failure: switch_resids"); + + /* drop all capabilities */ + if (!caps_down()) + die("failure: caps_down"); + + /* + * The {g,u}id 0 is not mapped in this idmapped mount so this + * needs to fail with EINVAL. + */ + if (!fchownat(open_tree_fd, FILE1, 0, 0, AT_SYMLINK_NOFOLLOW)) + die("failure: change ownership"); + if (errno != EINVAL) + die("failure: errno"); + + /* + * A user with fs{g,u}id 1000 must be allowed to change + * ownership of /target/file2 owned by {g,u}id 1000 in this + * idmapped mount to {g,u}id 1000. + */ + if (fchownat(open_tree_fd, FILE2, user1_uid, user1_gid, + AT_SYMLINK_NOFOLLOW)) + die("failure: change ownership"); + + /* Verify that the ownership is still {g,u}id 1000. */ + if (!expected_uid_gid(open_tree_fd, FILE2, AT_SYMLINK_NOFOLLOW, + user1_uid, user1_gid)) + die("failure: check ownership"); + + /* + * A user with fs{g,u}id 1000 must not be allowed to change + * ownership of /target/file2 owned by {g,u}id 1000 in this + * idmapped mount to {g,u}id 1001. + */ + if (!fchownat(open_tree_fd, FILE2, user2_uid, user2_gid, + AT_SYMLINK_NOFOLLOW)) + die("failure: change ownership"); + if (errno != EPERM) + die("failure: errno"); + + /* Verify that the ownership is still {g,u}id 1000. */ + if (!expected_uid_gid(open_tree_fd, FILE2, AT_SYMLINK_NOFOLLOW, + user1_uid, user1_gid)) + die("failure: check ownership"); + + /* + * A user with fs{g,u}id 1000 must not be allowed to change + * ownership of /target/file1 owned by {g,u}id 1001 in this + * idmapped mount to {g,u}id 1000. + */ + if (!fchownat(open_tree_fd, FILE1, user1_uid, user1_gid, + AT_SYMLINK_NOFOLLOW)) + die("failure: change ownership"); + if (errno != EPERM) + die("failure: errno"); + + /* Verify that the ownership is still {g,u}id 1001. */ + if (!expected_uid_gid(open_tree_fd, FILE1, AT_SYMLINK_NOFOLLOW, + user2_uid, user2_gid)) + die("failure: check ownership"); + + /* + * A user with fs{g,u}id 1000 must not be allowed to change + * ownership of /target/file1 owned by {g,u}id 1001 in this + * idmapped mount to {g,u}id 1001. + */ + if (!fchownat(open_tree_fd, FILE1, user2_uid, user2_gid, + AT_SYMLINK_NOFOLLOW)) + die("failure: change ownership"); + if (errno != EPERM) + die("failure: errno"); + + /* Verify that the ownership is still {g,u}id 1001. */ + if (!expected_uid_gid(open_tree_fd, FILE1, AT_SYMLINK_NOFOLLOW, + user2_uid, user2_gid)) + die("failure: check ownership"); + + exit(EXIT_SUCCESS); + } + if (wait_for_pid(pid)) + goto out; + + fret = 0; + log_debug("Ran test"); +out: + safe_close(attr.userns_fd); + safe_close(open_tree_fd); + + list_for_each_safe(it_cur, &idmap, it_next) { + list_del(it_cur); + free(it_cur->elem); + free(it_cur); + } + + return fret; +} + static void usage(void) { fprintf(stderr, "Description:\n"); fprintf(stderr, " Run idmapped mount tests\n\n"); fprintf(stderr, "Arguments:\n"); - fprintf(stderr, "--device Device used in the tests\n"); - fprintf(stderr, "--fstype Filesystem type used in the tests\n"); - fprintf(stderr, "--help Print help\n"); - fprintf(stderr, "--mountpoint Mountpoint of device\n"); - fprintf(stderr, "--supported Test whether idmapped mounts are supported on this filesystem\n"); - fprintf(stderr, "--scratch-mountpoint Mountpoint of scratch device used in the tests\n"); - fprintf(stderr, "--scratch-device Scratch device used in the tests\n"); - fprintf(stderr, "--test-core Run core idmapped mount testsuite\n"); - fprintf(stderr, "--test-fscaps-regression Run fscap regression tests\n"); - fprintf(stderr, "--test-nested-userns Run nested userns idmapped mount testsuite\n"); - fprintf(stderr, "--test-btrfs Run btrfs specific idmapped mount testsuite\n"); + fprintf(stderr, "--device Device used in the tests\n"); + fprintf(stderr, "--fstype Filesystem type used in the tests\n"); + fprintf(stderr, "--help Print help\n"); + fprintf(stderr, "--mountpoint Mountpoint of device\n"); + fprintf(stderr, "--supported Test whether idmapped mounts are supported on this filesystem\n"); + fprintf(stderr, "--scratch-mountpoint Mountpoint of scratch device used in the tests\n"); + fprintf(stderr, "--scratch-device Scratch device used in the tests\n"); + fprintf(stderr, "--test-core Run core idmapped mount testsuite\n"); + fprintf(stderr, "--test-fscaps-regression Run fscap regression tests\n"); + fprintf(stderr, "--test-nested-userns Run nested userns idmapped mount testsuite\n"); + fprintf(stderr, "--test-btrfs Run btrfs specific idmapped mount testsuite\n"); + fprintf(stderr, "--test-setattr-fix-968219708108 Run setattr regression tests\n"); _exit(EXIT_SUCCESS); } static const struct option longopts[] = { - {"device", required_argument, 0, 'd'}, - {"fstype", required_argument, 0, 'f'}, - {"mountpoint", required_argument, 0, 'm'}, - {"scratch-mountpoint", required_argument, 0, 'a'}, - {"scratch-device", required_argument, 0, 'e'}, - {"supported", no_argument, 0, 's'}, - {"help", no_argument, 0, 'h'}, - {"test-core", no_argument, 0, 'c'}, - {"test-fscaps-regression", no_argument, 0, 'g'}, - {"test-nested-userns", no_argument, 0, 'n'}, - {"test-btrfs", no_argument, 0, 'b'}, - {NULL, 0, 0, 0}, + {"device", required_argument, 0, 'd'}, + {"fstype", required_argument, 0, 'f'}, + {"mountpoint", required_argument, 0, 'm'}, + {"scratch-mountpoint", required_argument, 0, 'a'}, + {"scratch-device", required_argument, 0, 'e'}, + {"supported", no_argument, 0, 's'}, + {"help", no_argument, 0, 'h'}, + {"test-core", no_argument, 0, 'c'}, + {"test-fscaps-regression", no_argument, 0, 'g'}, + {"test-nested-userns", no_argument, 0, 'n'}, + {"test-btrfs", no_argument, 0, 'b'}, + {"test-setattr-fix-968219708108", no_argument, 0, 'i'}, + {NULL, 0, 0, 0}, }; struct t_idmapped_mounts { @@ -13449,6 +13869,11 @@ struct t_idmapped_mounts t_btrfs[] = { { btrfs_subvolume_lookup_user, "test unprivileged subvolume lookup", }, }; +/* Test for commit 968219708108 ("fs: handle circular mappings correctly"). */ +struct t_idmapped_mounts t_setattr_fix_968219708108[] = { + { setattr_fix_968219708108, "test that setattr works correctly", }, +}; + static bool run_test(struct t_idmapped_mounts suite[], size_t suite_size) { int i; @@ -13487,7 +13912,8 @@ int main(int argc, char *argv[]) int fret, ret; int index = 0; bool supported = false, test_btrfs = false, test_core = false, - test_fscaps_regression = false, test_nested_userns = false; + test_fscaps_regression = false, test_nested_userns = false, + test_setattr_fix_968219708108 = false; while ((ret = getopt_long_only(argc, argv, "", longopts, &index)) != -1) { switch (ret) { @@ -13521,6 +13947,9 @@ int main(int argc, char *argv[]) case 'e': t_device_scratch = optarg; break; + case 'i': + test_setattr_fix_968219708108 = true; + break; case 'h': /* fallthrough */ default: @@ -13609,6 +14038,11 @@ int main(int argc, char *argv[]) if (test_btrfs && !run_test(t_btrfs, ARRAY_SIZE(t_btrfs))) goto out; + if (test_setattr_fix_968219708108 && + !run_test(t_setattr_fix_968219708108, + ARRAY_SIZE(t_setattr_fix_968219708108))) + goto out; + fret = EXIT_SUCCESS; out: diff --git a/src/idmapped-mounts/utils.c b/src/idmapped-mounts/utils.c index c2afa8dc..faf06fcd 100644 --- a/src/idmapped-mounts/utils.c +++ b/src/idmapped-mounts/utils.c @@ -183,6 +183,43 @@ static int map_ids_from_idmap(struct list *idmap, pid_t pid) return 0; } +#ifdef DEBUG_TRACE +static void __print_idmaps(pid_t pid, bool gid) +{ + char path_mapping[STRLITERALLEN("/proc/") + INTTYPE_TO_STRLEN(pid_t) + + STRLITERALLEN("/_id_map") + 1]; + char *line = NULL; + size_t len = 0; + int ret; + FILE *f; + + ret = snprintf(path_mapping, sizeof(path_mapping), "/proc/%d/%cid_map", + pid, gid ? 'g' : 'u'); + if (ret < 0 || (size_t)ret >= sizeof(path_mapping)) + return; + + f = fopen(path_mapping, "r"); + if (!f) + return; + + while ((ret = getline(&line, &len, f)) > 0) + fprintf(stderr, "%s", line); + + fclose(f); + free(line); +} + +static void print_idmaps(pid_t pid) +{ + __print_idmaps(pid, false); + __print_idmaps(pid, true); +} +#else +static void print_idmaps(pid_t pid) +{ +} +#endif + int get_userns_fd_from_idmap(struct list *idmap) { int ret; @@ -199,10 +236,12 @@ int get_userns_fd_from_idmap(struct list *idmap) return ret; ret = snprintf(path_ns, sizeof(path_ns), "/proc/%d/ns/user", pid); - if (ret < 0 || (size_t)ret >= sizeof(path_ns)) + if (ret < 0 || (size_t)ret >= sizeof(path_ns)) { ret = -EIO; - else + } else { ret = open(path_ns, O_RDONLY | O_CLOEXEC | O_NOCTTY); + print_idmaps(pid); + } (void)kill(pid, SIGKILL); (void)wait_for_pid(pid); diff --git a/tests/generic/651 b/tests/generic/651 new file mode 100755 index 00000000..a4508e65 --- /dev/null +++ b/tests/generic/651 @@ -0,0 +1,33 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2021 Christian Brauner. All Rights Reserved. +# +# FS QA Test 651 +# +# This is a test for the fix +# commit 968219708108 ("fs: handle circular mappings correctly") +# in Linux. It verifies that setattr for {g,u}id work correctly. +# +. ./common/preamble +_begin_fstest auto attr cap idmapped mount perms + +# Import common functions. +. ./common/filter + +# real QA test starts here + +_supported_fs generic +_require_idmapped_mounts +_require_test +_require_user fsgqa +_require_user fsgqa2 +_require_group fsgqa +_require_group fsgqa2 + +echo "Silence is golden" + +$here/src/idmapped-mounts/idmapped-mounts --test-setattr-fix-968219708108 \ + --device "$TEST_DEV" --mount "$TEST_DIR" --fstype "$FSTYP" + +status=$? +exit diff --git a/tests/generic/651.out b/tests/generic/651.out new file mode 100644 index 00000000..51d73665 --- /dev/null +++ b/tests/generic/651.out @@ -0,0 +1,2 @@ +QA output created by 651 +Silence is golden