bcc: fix CVE-2024-2314kirkstone

If kernel headers need to be extracted, bcc will attempt to load them
from a temporary directory. An unprivileged attacker could use this to
force bcc to load compromised linux headers. Linux distributions which
provide kernel headers by default are not affected by default.

Reference:
https://nvd.nist.gov/vuln/detail/CVE-2024-2314

Upstream-patch:
https://github.com/iovisor/bcc/commit/008ea09e891194c072f2a9305a3c872a241dc342

Signed-off-by: Divya Chellam <divya.chellam@windriver.com>

2 files changed, 73 insertions, 0 deletions

diff --git a/dynamic-layers/openembedded-layer/recipes-devtools/bcc/bcc/CVE-2024-2314.patch b/dynamic-layers/openembedded-layer/recipes-devtools/bcc/bcc/CVE-2024-2314.patch
new file mode 100644
index 0000000..cde67b3
--- /dev/null
+++ b/dynamic-layers/openembedded-layer/recipes-devtools/bcc/bcc/CVE-2024-2314.patch
@@ -0,0 +1,72 @@
+From 008ea09e891194c072f2a9305a3c872a241dc342 Mon Sep 17 00:00:00 2001
+From: Brendan Gregg <brendan@intel.com>
+Date: Thu, 7 Mar 2024 05:27:14 +1100
+Subject: [PATCH] clang: check header ownership (#4928)
+
+Example testing with a brendan-owned /tmp/kheaders file (note the "ERROR:" message):
+
+~/bcc/build$ sudo /usr/share/bcc/tools/biosnoop
+ERROR: header file ownership unexpected: /tmp/kheaders-5.15.47-internal
+<built-in>:1:10: fatal error: './include/linux/kconfig.h' file not found
+         ^~~~~~~~~~~~~~~~~~~~~~~~~~~
+1 error generated.
+Traceback (most recent call last):
+  File "/usr/share/bcc/tools/biosnoop", line 335, in <module>
+    b = BPF(text=bpf_text)
+  File "/usr/lib/python3/dist-packages/bcc-0.1.5+6cd27218-py3.10.egg/bcc/__init__.py", line 479, in __init__
+Exception: Failed to compile BPF module <text>
+~/bcc/build$ ls -lhd /tmp/kheaders-5.15.47-internal
+drwxrwxr-x 2 brendan dev 4.0K Mar  6 02:50 /tmp/kheaders-5.15.47-internal
+
+No error when chown'd back to root.
+
+CVE: CVE-2024-2314
+
+Upstream-Status: Backport [https://github.com/iovisor/bcc/commit/008ea09e891194c072f2a9305a3c872a241dc342]
+
+Signed-off-by: Divya Chellam <divya.chellam@windriver.com>
+---
+ src/cc/frontends/clang/kbuild_helper.cc | 15 +++++++++++----
+ 1 file changed, 11 insertions(+), 4 deletions(-)
+
+diff --git a/src/cc/frontends/clang/kbuild_helper.cc b/src/cc/frontends/clang/kbuild_helper.cc
+index 5c57c13e..d13be427 100644
+--- a/src/cc/frontends/clang/kbuild_helper.cc
++++ b/src/cc/frontends/clang/kbuild_helper.cc
+@@ -136,15 +136,22 @@ int KBuildHelper::get_flags(const char *uname_machine, vector<string> *cflags) {
+   return 0;
+ }
+
+-static inline int file_exists(const char *f)
++static inline int file_exists_and_ownedby(const char *f, uid_t uid)
+ {
+   struct stat buffer;
+-  return (stat(f, &buffer) == 0);
++  int ret;
++  if ((ret = stat(f, &buffer)) == 0) {
++    if (buffer.st_uid != uid) {
++      std::cout << "ERROR: header file ownership unexpected: " << std::string(f) << "\n";
++      return -1;
++    }
++  }
++  return ret;
+ }
+
+ static inline int proc_kheaders_exists(void)
+ {
+-  return file_exists(PROC_KHEADERS_PATH);
++  return file_exists_and_ownedby(PROC_KHEADERS_PATH, 0);
+ }
+
+ static inline int extract_kheaders(const std::string &dirpath,
+@@ -210,7 +217,7 @@ int get_proc_kheaders(std::string &dirpath)
+   snprintf(dirpath_tmp, 256, "/tmp/kheaders-%s", uname_data.release);
+   dirpath = std::string(dirpath_tmp);
+
+-  if (file_exists(dirpath_tmp))
++  if (file_exists_and_ownedby(dirpath_tmp, 0))
+     return 0;
+
+   // First time so extract it
+--
+2.40.0
diff --git a/dynamic-layers/openembedded-layer/recipes-devtools/bcc/bcc_0.24.0.bb b/dynamic-layers/openembedded-layer/recipes-devtools/bcc/bcc_0.24.0.bb
index b24e153..a3ceddb 100644
--- a/dynamic-layers/openembedded-layer/recipes-devtools/bcc/bcc_0.24.0.bb
+++ b/dynamic-layers/openembedded-layer/recipes-devtools/bcc/bcc_0.24.0.bb
@@ -29,6 +29,7 @@ SRC_URI = "gitsm://github.com/iovisor/bcc;branch=master;protocol=https \
            file://0001-Vendor-just-enough-extra-headers-to-allow-libbpf-to-.patch \
            file://run-ptest \
            file://ptest_wrapper.sh \
+           file://CVE-2024-2314.patch \
            "
 
 SRCREV = "8f40d6f57a8d94e7aee74ce358572d34d31b4ed4"