diff options
Diffstat (limited to 'git-compat-util.h')
| -rw-r--r-- | git-compat-util.h | 58 |
1 files changed, 57 insertions, 1 deletions
diff --git a/git-compat-util.h b/git-compat-util.h index c1e9cf4f73..f685a4f0fa 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -398,12 +398,68 @@ static inline int git_offset_1st_component(const char *path) #endif #ifndef is_path_owned_by_current_user + +#ifdef __TANDEM +#define ROOT_UID 65535 +#else +#define ROOT_UID 0 +#endif + +/* + * Do not use this function when + * (1) geteuid() did not say we are running as 'root', or + * (2) using this function will compromise the system. + * + * PORTABILITY WARNING: + * This code assumes uid_t is unsigned because that is what sudo does. + * If your uid_t type is signed and all your ids are positive then it + * should all work fine. + * If your version of sudo uses negative values for uid_t or it is + * buggy and return an overflowed value in SUDO_UID, then git might + * fail to grant access to your repository properly or even mistakenly + * grant access to someone else. + * In the unlikely scenario this happened to you, and that is how you + * got to this message, we would like to know about it; so sent us an + * email to git@vger.kernel.org indicating which platform you are + * using and which version of sudo, so we can improve this logic and + * maybe provide you with a patch that would prevent this issue again + * in the future. + */ +static inline void extract_id_from_env(const char *env, uid_t *id) +{ + const char *real_uid = getenv(env); + + /* discard anything empty to avoid a more complex check below */ + if (real_uid && *real_uid) { + char *endptr = NULL; + unsigned long env_id; + + errno = 0; + /* silent overflow errors could trigger a bug here */ + env_id = strtoul(real_uid, &endptr, 10); + if (!*endptr && !errno) + *id = env_id; + } +} + static inline int is_path_owned_by_current_uid(const char *path) { struct stat st; + uid_t euid; + if (lstat(path, &st)) return 0; - return st.st_uid == geteuid(); + + euid = geteuid(); + if (euid == ROOT_UID) + { + if (st.st_uid == ROOT_UID) + return 1; + else + extract_id_from_env("SUDO_UID", &euid); + } + + return st.st_uid == euid; } #define is_path_owned_by_current_user is_path_owned_by_current_uid |