diff options
Diffstat (limited to 'apt-pkg/acquire.cc')
| -rw-r--r-- | apt-pkg/acquire.cc | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/apt-pkg/acquire.cc b/apt-pkg/acquire.cc index f8b077367..cb32e8f2b 100644 --- a/apt-pkg/acquire.cc +++ b/apt-pkg/acquire.cc @@ -34,6 +34,7 @@ #include <stdlib.h> #include <string.h> #include <unistd.h> +#include <fcntl.h> #include <pwd.h> #include <grp.h> #include <dirent.h> @@ -446,8 +447,58 @@ void pkgAcquire::RunFds(fd_set *RSet,fd_set *WSet) /* This runs the queues. It manages a select loop for all of the Worker tasks. The workers interact with the queues and items to manage the actual fetch. */ +static void CheckDropPrivsMustBeDisabled(pkgAcquire const &Fetcher) +{ + if(getuid() != 0) + return; + + std::string SandboxUser = _config->Find("APT::Sandbox::User"); + if (SandboxUser.empty()) + return; + + struct passwd const * const pw = getpwnam(SandboxUser.c_str()); + if (pw == NULL) + return; + + if (setegid(pw->pw_gid) != 0) + _error->Errno("setegid", "setegid %u failed", pw->pw_gid); + if (seteuid(pw->pw_uid) != 0) + _error->Errno("seteuid", "seteuid %u failed", pw->pw_uid); + + bool dropPrivs = true; + for (pkgAcquire::ItemCIterator I = Fetcher.ItemsBegin(); + I != Fetcher.ItemsEnd() && dropPrivs == true; ++I) + { + if ((*I)->DestFile.empty()) + continue; + + // we check directory instead of file as the file might or might not + // exist already as a link or not which complicates everything… + std::string dirname = flNotFile((*I)->DestFile); + if (DirectoryExists(dirname)) + ; + else + continue; // assume it is created correctly by the acquire system + + if (faccessat(AT_FDCWD, dirname.c_str(), R_OK | W_OK | X_OK, AT_EACCESS | AT_SYMLINK_NOFOLLOW) != 0) + { + dropPrivs = false; + _error->WarningE("pkgAcquire::Run", _("Can't drop privileges for downloading as file '%s' couldn't be accessed by user '%s'."), + (*I)->DestFile.c_str(), SandboxUser.c_str()); + _config->Set("APT::Sandbox::User", ""); + break; + } + } + + if (seteuid(0) != 0) + _error->Errno("seteuid", "seteuid %u failed", 0); + if (setegid(0) != 0) + _error->Errno("setegid", "setegid %u failed", 0); +} pkgAcquire::RunResult pkgAcquire::Run(int PulseIntervall) { + CheckDropPrivsMustBeDisabled(*this); + Running = true; for (Queue *I = Queues; I != 0; I = I->Next) |