[scarthgap][PATCH] unfs3: Fix race issue causing a glibc test hang

[scarthgap][PATCH] unfs3: Fix race issue causing a glibc test hang

[Hemanth.KumarMD]

From: Hemanth Kumar M D <Hemanth.KumarMD@windriver.com>

When running glibc tests under user mode NFS, tst-syslog was causing a hang. The
hang was traced to unfsd exitting with a buffer overflow being detected.

This was traced down to mksocket() where we'd see:

socket path '/media/build/poky/build/build-st-2118464/tmp/work/x86-64-v3-poky-linux/glibc-testsuite/2.42+git/build-x86_64-poky-linux/testroot.root/dev/log' is too long at 141 vs 108

There is a length check in mknod_args() but obj may not be setup at this point by
cat_name() since the functions can be executed out of order according to C.

To avoid this, make the order explict. This means the length is checked and we
avoid the buffer overflow. This will likely cause the glibc test to fail however
it won't hang, which is a win.

[YOCTO #16113]

(From OE-Core rev: e51d5e19cb1ba1d5ad7442064b64821d178bc9ca)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Hemanth Kumar M D <Hemanth.KumarMD@windriver.com>
---
 .../unfs3/unfs3/fixrace.patch                 | 35 +++++++++++++++++++
 meta/recipes-devtools/unfs3/unfs3_git.bb      |  1 +
 2 files changed, 36 insertions(+)
 create mode 100644 meta/recipes-devtools/unfs3/unfs3/fixrace.patch

diff --git a/meta/recipes-devtools/unfs3/unfs3/fixrace.patch b/meta/recipes-devtools/unfs3/unfs3/fixrace.patch
new file mode 100644
index 0000000000..2a659f5bc6
--- /dev/null
+++ b/meta/recipes-devtools/unfs3/unfs3/fixrace.patch
@@ -0,0 +1,35 @@
+When running glibc tests under user mode NFS, tst-syslog was causing a hang. The
+hang was traced to unfsd exitting with a buffer overflow being detected.
+
+This was traced down to mksocket() where we'd see:
+
+socket path '/media/build/poky/build/build-st-2118464/tmp/work/x86-64-v3-poky-linux/glibc-testsuite/2.42+git/build-x86_64-poky-linux/testroot.root/dev/log' is too long at 141 vs 108
+
+There is a length check in mknod_args() but obj may not be setup at this point by
+cat_name() since the functions can be executed out of order according to C.
+
+To avoid this, make the order explict. This means the length is checked and we
+avoid the buffer overflow. This will likely cause the glibc test to fail however
+it won't hang, which is a win.
+
+Upstream-Status: Pending
+
+diff --git a/nfs.c b/nfs.c
+index 3e92f87..784089a 100644
+--- a/nfs.c
++++ b/nfs.c
+@@ -776,9 +776,11 @@ MKNOD3res *nfsproc3_mknod_3_svc(MKNOD3args * argp, struct svc_req * rqstp)
+ 
+     PREP(path, argp->where.dir);
+     pre = get_pre_cached();
+-    result.status =
+-	join3(cat_name(path, argp->where.name, obj),
+-	      mknod_args(argp->what, obj, &new_mode, &dev), exports_rw());
++    result.status = cat_name(path, argp->where.name, obj);
++    if (result.status == NFS3_OK)
++        result.status = mknod_args(argp->what, obj, &new_mode, &dev);
++    if (result.status == NFS3_OK)
++        result.status = exports_rw();
+ 
+     cluster_create(obj, rqstp, &result.status);
+ 
diff --git a/meta/recipes-devtools/unfs3/unfs3_git.bb b/meta/recipes-devtools/unfs3/unfs3_git.bb
index c5b7898b3c..50d5cd272f 100644
--- a/meta/recipes-devtools/unfs3/unfs3_git.bb
+++ b/meta/recipes-devtools/unfs3/unfs3_git.bb
@@ -18,6 +18,7 @@ SRC_URI = "git://github.com/unfs3/unfs3.git;protocol=https;branch=master \
            file://0001-locate.c-Include-attr.h.patch \
            file://0001-fix-building-on-macOS.patch \
            file://0001-attr-fix-utime-for-symlink.patch \
+           file://fixrace.patch \
            "
 SRCREV = "c8f2d2cd4529955419bad0e163f88d47ff176b8d"
 UPSTREAM_CHECK_GITTAGREGEX = "unfs3\-(?P<pver>\d+(\.\d+)+)"
-- 
2.49.0

Patchtest results for [scarthgap][PATCH] unfs3: Fix race issue causing a glibc test hang

[patchtest]

[-- Attachment #1: Type: text/plain, Size: 2103 bytes --]

Thank you for your submission. Patchtest identified one
or more issues with the patch. Please see the log below for
more information:

---
Testing patch /home/patchtest/share/mboxes/scarthgap-unfs3-Fix-race-issue-causing-a-glibc-test-hang.patch

FAIL: test Signed-off-by presence: A patch file has been added without a Signed-off-by tag: 'fixrace.patch' (test_patch.TestPatch.test_signed_off_by_presence)

PASS: test CVE tag format (test_patch.TestPatch.test_cve_tag_format)
PASS: test Signed-off-by presence (test_mbox.TestMbox.test_signed_off_by_presence)
PASS: test Upstream-Status presence (test_patch.TestPatch.test_upstream_status_presence_format)
PASS: test author valid (test_mbox.TestMbox.test_author_valid)
PASS: test bugzilla entry format (test_mbox.TestMbox.test_bugzilla_entry_format)
PASS: test commit message presence (test_mbox.TestMbox.test_commit_message_presence)
PASS: test commit message user tags (test_mbox.TestMbox.test_commit_message_user_tags)
PASS: test mbox format (test_mbox.TestMbox.test_mbox_format)
PASS: test non-AUH upgrade (test_mbox.TestMbox.test_non_auh_upgrade)
PASS: test shortlog format (test_mbox.TestMbox.test_shortlog_format)
PASS: test shortlog length (test_mbox.TestMbox.test_shortlog_length)
PASS: test target mailing list (test_mbox.TestMbox.test_target_mailing_list)

SKIP: pretest pylint: No python related patches, skipping test (test_python_pylint.PyLint.pretest_pylint)
SKIP: test pylint: No python related patches, skipping test (test_python_pylint.PyLint.test_pylint)
SKIP: test series merge on head: Merge test is disabled for now (test_mbox.TestMbox.test_series_merge_on_head)

---

Please address the issues identified and
submit a new revision of the patch, or alternatively, reply to this
email with an explanation of why the patch should be accepted. If you
believe these results are due to an error in patchtest, please submit a
bug at https://bugzilla.yoctoproject.org/ (use the 'Patchtest' category
under 'Yocto Project Subprojects'). For more information on specific
failures, see: https://wiki.yoctoproject.org/wiki/Patchtest. Thank
you!