diff options
| author | Brendan Gregg <brendan@intel.com> | 2024-03-07 05:27:14 +1100 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-03-06 10:27:14 -0800 |
| commit | 008ea09e891194c072f2a9305a3c872a241dc342 (patch) | |
| tree | f8b8627cdcb806ebd7516314240067b687a7796d | |
| parent | 6cd272189771bbc7120d9d834e2588b93d8e9cfa (diff) | |
| download | bcc-008ea09e891194c072f2a9305a3c872a241dc342.tar.gz | |
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
#include "./include/linux/kconfig.h"
^~~~~~~~~~~~~~~~~~~~~~~~~~~
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.
| -rw-r--r-- | src/cc/frontends/clang/kbuild_helper.cc | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/src/cc/frontends/clang/kbuild_helper.cc b/src/cc/frontends/clang/kbuild_helper.cc index 50e2da9a..d4b9d3e6 100644 --- a/src/cc/frontends/clang/kbuild_helper.cc +++ b/src/cc/frontends/clang/kbuild_helper.cc @@ -140,15 +140,22 @@ 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 const char *get_tmp_dir() { @@ -224,7 +231,7 @@ int get_proc_kheaders(std::string &dirpath) 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 |