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avoid assimilating
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@G4Vi
G4Vi committed Jan 19, 2024
1 parent 2e35c7b commit f34afc7
Showing 1 changed file with 133 additions and 33 deletions.
166 changes: 133 additions & 33 deletions libc/proc/fexecve.c
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Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,7 @@
#include "libc/calls/calls.h"
#include "libc/calls/cp.internal.h"
#include "libc/calls/internal.h"
#include "libc/calls/state.internal.h"
#include "libc/calls/struct/sigset.internal.h"
#include "libc/calls/struct/stat.internal.h"
#include "libc/calls/syscall-sysv.internal.h"
Expand Down Expand Up @@ -199,9 +200,9 @@ static int fd_to_mem_fd(const int infd, char *path) {
bool success = readRc != -1;
if (success) {
int ziperror;
if ((st.st_size > 8) && IsApeMagic(space)) {
success = ape_to_elf(space, st.st_size);
}
//if ((st.st_size > 8) && IsApeMagic(space)) {
// success = ape_to_elf(space, st.st_size);
//}
// we need to preserve the fd over exec if there's zipos
if (success && _weaken(GetZipEocd) && _weaken(GetZipEocd)(space, st.st_size, &ziperror)) {
int flags = fcntl(fd, F_GETFD);
Expand Down Expand Up @@ -232,6 +233,30 @@ static int fd_to_mem_fd(const int infd, char *path) {
return -1;
}

static int isZipFd(const int fd) {
if (!_weaken(mmap) || !_weaken(munmap) || !_weaken(GetZipEocd)) {
return enosys();
}
if (__vforked) {
return 0;
}
struct stat st;
if (fstat(fd, &st) == -1) {
return -1;
}
void *space = _weaken(mmap)(0, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
if (space == MAP_FAILED) {
STRACE("map failed");
return -1;
}
int ziperror;
int rc = _weaken(GetZipEocd)(space, st.st_size, &ziperror) != NULL;
if(_weaken(munmap)(space, st.st_size) == -1) {
return -1;
}
return rc;
}

/**
* Executes binary executable at file descriptor.
*
Expand Down Expand Up @@ -260,55 +285,130 @@ int fexecve(int fd, char *const argv[], char *const envp[]) {
rc = enosys();
break;
}
if (!__isfdkind(fd, kFdZip)) {
bool memfdReq;
int newfd = fd;
if (__isfdkind(fd, kFdZip)) {
BEGIN_CANCELATION_POINT;
BLOCK_SIGNALS;
strace_enabled(-1);
memfdReq = ((rc = fcntl(fd, F_GETFD)) != -1) && (rc & FD_CLOEXEC) &&
IsAPEFd(fd);
newfd = fd_to_mem_fd(fd, NULL);
strace_enabled(+1);
ALLOW_SIGNALS;
END_CANCELATION_POINT;
if (rc == -1) {
if (newfd == -1) {
break;
} else if (!memfdReq) {
fexecve_impl(fd, argv, envp);
if (errno != ENOEXEC) {
break;
}
savedErr = ENOEXEC;
}
}
int newfd;
char *path = alloca(PATH_MAX);
int isZipFdRc;
BEGIN_CANCELATION_POINT;
BLOCK_SIGNALS;
strace_enabled(-1);
newfd = fd_to_mem_fd(fd, path);
//strace_enabled(-1);
isZipFdRc = isZipFd(newfd);
strace_enabled(+1);
ALLOW_SIGNALS;
END_CANCELATION_POINT;
if (newfd == -1) {
break;
}
size_t numenvs;
for (numenvs = 0; envp[numenvs];) ++numenvs;
static _Thread_local char *envs[500];
memcpy(envs, envp, numenvs * sizeof(char *));
envs[numenvs] = path;
envs[numenvs + 1] = NULL;
fexecve_impl(newfd, argv, envs);
if (!savedErr) {
savedErr = errno;
if (isZipFdRc == -1) {
//savedErr = EACCES;
//STRACE("EACCESS 1");
//break;
isZipFdRc = 0;
}
bool isAPE;
BEGIN_CANCELATION_POINT;
BLOCK_SIGNALS;
strace_enabled(-1);
close(newfd);
strace_enabled(+1);
isAPE = IsAPEFd(newfd);
ALLOW_SIGNALS;
END_CANCELATION_POINT;
if ((isZipFdRc == 1) || isAPE) {
int flags = fcntl(newfd, F_GETFD);
if ((flags == -1) || (fcntl(newfd, F_SETFD, flags & (~FD_CLOEXEC)) == -1)) {
savedErr = EACCES;
STRACE("EACCESS 2");
break;
}
const int highfd = fcntl(newfd, F_DUPFD, 9001);
if (highfd != -1) {
close(newfd);
newfd = highfd;
}
}
if (isZipFdRc == 1) {
char *path = alloca(PATH_MAX);
FormatInt32(stpcpy(path, "COSMOPOLITAN_INIT_ZIPOS="), newfd);
size_t numenvs;
for (numenvs = 0; envp[numenvs];) ++numenvs;
static _Thread_local char *envs[500];
memcpy(envs, envp, numenvs * sizeof(char *));
envs[numenvs] = path;
envs[numenvs + 1] = NULL;
envp = envs;
}
if (isAPE) {
char path[14 + 12];
FormatInt32(stpcpy(path, "/proc/self/fd/"), newfd);
rc = sys_execve(path, argv, envp);
savedErr = errno;
BEGIN_CANCELATION_POINT;
BLOCK_SIGNALS;
strace_enabled(-1);
if (newfd != fd) {
close(newfd);
}
strace_enabled(+1);
ALLOW_SIGNALS;
END_CANCELATION_POINT;
break;
}
fexecve_impl(newfd, argv, envp);
savedErr = errno;
//if (!__isfdkind(fd, kFdZip)) {
// bool memfdReq;
// BEGIN_CANCELATION_POINT;
// BLOCK_SIGNALS;
// strace_enabled(-1);
// memfdReq = ((rc = fcntl(fd, F_GETFD)) != -1) && (rc & FD_CLOEXEC) &&
// IsAPEFd(fd);
// strace_enabled(+1);
// ALLOW_SIGNALS;
// END_CANCELATION_POINT;
// if (rc == -1) {
// break;
// } else if (!memfdReq) {
// fexecve_impl(fd, argv, envp);
// if (errno != ENOEXEC) {
// break;
// }
// savedErr = ENOEXEC;
// }
//}
//int newfd;
//char *path = alloca(PATH_MAX);
//BEGIN_CANCELATION_POINT;
//BLOCK_SIGNALS;
//strace_enabled(-1);
//newfd = fd_to_mem_fd(fd, path);
//strace_enabled(+1);
//ALLOW_SIGNALS;
//END_CANCELATION_POINT;
//if (newfd == -1) {
// break;
//}
//size_t numenvs;
//for (numenvs = 0; envp[numenvs];) ++numenvs;
//static _Thread_local char *envs[500];
//memcpy(envs, envp, numenvs * sizeof(char *));
//envs[numenvs] = path;
//envs[numenvs + 1] = NULL;
//fexecve_impl(newfd, argv, envs);
//if (!savedErr) {
// savedErr = errno;
//}
//BEGIN_CANCELATION_POINT;
//BLOCK_SIGNALS;
//strace_enabled(-1);
//close(newfd);
//strace_enabled(+1);
//ALLOW_SIGNALS;
//END_CANCELATION_POINT;
} while (0);
if (savedErr) {
errno = savedErr;
Expand Down

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