machined: when copying files from/to userns containers chown to root

This changes the file copy logic of machined to set the UID/GID of all
copied files to 0 if the host and container do not share the same user
namespace.

Fixes: #4078
This commit is contained in:
Lennart Poettering
2017-02-17 10:22:28 +01:00
parent 1c876927e4
commit d01cd40196
6 changed files with 102 additions and 36 deletions
+74 -25
View File
@@ -45,6 +45,7 @@
#include "strv.h"
#include "time-util.h"
#include "umask-util.h"
#include "user-util.h"
#include "xattr-util.h"
#define COPY_BUFFER_SIZE (16*1024u)
@@ -176,7 +177,16 @@ int copy_bytes(int fdf, int fdt, uint64_t max_bytes, CopyFlags copy_flags) {
return 0; /* return 0 if we hit EOF earlier than the size limit */
}
static int fd_copy_symlink(int df, const char *from, const struct stat *st, int dt, const char *to) {
static int fd_copy_symlink(
int df,
const char *from,
const struct stat *st,
int dt,
const char *to,
uid_t override_uid,
gid_t override_gid,
CopyFlags copy_flags) {
_cleanup_free_ char *target = NULL;
int r;
@@ -191,13 +201,25 @@ static int fd_copy_symlink(int df, const char *from, const struct stat *st, int
if (symlinkat(target, dt, to) < 0)
return -errno;
if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
if (fchownat(dt, to,
uid_is_valid(override_uid) ? override_uid : st->st_uid,
gid_is_valid(override_gid) ? override_gid : st->st_gid,
AT_SYMLINK_NOFOLLOW) < 0)
return -errno;
return 0;
}
static int fd_copy_regular(int df, const char *from, const struct stat *st, int dt, const char *to, CopyFlags copy_flags) {
static int fd_copy_regular(
int df,
const char *from,
const struct stat *st,
int dt,
const char *to,
uid_t override_uid,
gid_t override_gid,
CopyFlags copy_flags) {
_cleanup_close_ int fdf = -1, fdt = -1;
struct timespec ts[2];
int r, q;
@@ -220,7 +242,9 @@ static int fd_copy_regular(int df, const char *from, const struct stat *st, int
return r;
}
if (fchown(fdt, st->st_uid, st->st_gid) < 0)
if (fchown(fdt,
uid_is_valid(override_uid) ? override_uid : st->st_uid,
gid_is_valid(override_gid) ? override_gid : st->st_gid) < 0)
r = -errno;
if (fchmod(fdt, st->st_mode & 07777) < 0)
@@ -229,7 +253,6 @@ static int fd_copy_regular(int df, const char *from, const struct stat *st, int
ts[0] = st->st_atim;
ts[1] = st->st_mtim;
(void) futimens(fdt, ts);
(void) copy_xattr(fdf, fdt);
q = close(fdt);
@@ -243,7 +266,15 @@ static int fd_copy_regular(int df, const char *from, const struct stat *st, int
return r;
}
static int fd_copy_fifo(int df, const char *from, const struct stat *st, int dt, const char *to) {
static int fd_copy_fifo(
int df,
const char *from,
const struct stat *st,
int dt,
const char *to,
uid_t override_uid,
gid_t override_gid,
CopyFlags copy_flags) {
int r;
assert(from);
@@ -254,7 +285,10 @@ static int fd_copy_fifo(int df, const char *from, const struct stat *st, int dt,
if (r < 0)
return -errno;
if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
if (fchownat(dt, to,
uid_is_valid(override_uid) ? override_uid : st->st_uid,
gid_is_valid(override_gid) ? override_gid : st->st_gid,
AT_SYMLINK_NOFOLLOW) < 0)
r = -errno;
if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
@@ -263,7 +297,15 @@ static int fd_copy_fifo(int df, const char *from, const struct stat *st, int dt,
return r;
}
static int fd_copy_node(int df, const char *from, const struct stat *st, int dt, const char *to) {
static int fd_copy_node(
int df,
const char *from,
const struct stat *st,
int dt,
const char *to,
uid_t override_uid,
gid_t override_gid,
CopyFlags copy_flags) {
int r;
assert(from);
@@ -274,7 +316,10 @@ static int fd_copy_node(int df, const char *from, const struct stat *st, int dt,
if (r < 0)
return -errno;
if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
if (fchownat(dt, to,
uid_is_valid(override_uid) ? override_uid : st->st_uid,
gid_is_valid(override_gid) ? override_gid : st->st_gid,
AT_SYMLINK_NOFOLLOW) < 0)
r = -errno;
if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
@@ -290,6 +335,8 @@ static int fd_copy_directory(
int dt,
const char *to,
dev_t original_device,
uid_t override_uid,
gid_t override_gid,
CopyFlags copy_flags) {
_cleanup_close_ int fdf = -1, fdt = -1;
@@ -343,15 +390,15 @@ static int fd_copy_directory(
continue;
if (S_ISREG(buf.st_mode))
q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name, copy_flags);
q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags);
else if (S_ISDIR(buf.st_mode))
q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, copy_flags);
q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, override_uid, override_gid, copy_flags);
else if (S_ISLNK(buf.st_mode))
q = fd_copy_symlink(dirfd(d), de->d_name, &buf, fdt, de->d_name);
q = fd_copy_symlink(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags);
else if (S_ISFIFO(buf.st_mode))
q = fd_copy_fifo(dirfd(d), de->d_name, &buf, fdt, de->d_name);
q = fd_copy_fifo(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags);
else if (S_ISBLK(buf.st_mode) || S_ISCHR(buf.st_mode) || S_ISSOCK(buf.st_mode))
q = fd_copy_node(dirfd(d), de->d_name, &buf, fdt, de->d_name);
q = fd_copy_node(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags);
else
q = -EOPNOTSUPP;
@@ -368,7 +415,9 @@ static int fd_copy_directory(
st->st_mtim
};
if (fchown(fdt, st->st_uid, st->st_gid) < 0)
if (fchown(fdt,
uid_is_valid(override_uid) ? override_uid : st->st_uid,
gid_is_valid(override_gid) ? override_gid : st->st_gid) < 0)
r = -errno;
if (fchmod(fdt, st->st_mode & 07777) < 0)
@@ -381,7 +430,7 @@ static int fd_copy_directory(
return r;
}
int copy_tree_at(int fdf, const char *from, int fdt, const char *to, CopyFlags copy_flags) {
int copy_tree_at(int fdf, const char *from, int fdt, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags) {
struct stat st;
assert(from);
@@ -391,21 +440,21 @@ int copy_tree_at(int fdf, const char *from, int fdt, const char *to, CopyFlags c
return -errno;
if (S_ISREG(st.st_mode))
return fd_copy_regular(fdf, from, &st, fdt, to, copy_flags);
return fd_copy_regular(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags);
else if (S_ISDIR(st.st_mode))
return fd_copy_directory(fdf, from, &st, fdt, to, st.st_dev, copy_flags);
return fd_copy_directory(fdf, from, &st, fdt, to, st.st_dev, override_uid, override_gid, copy_flags);
else if (S_ISLNK(st.st_mode))
return fd_copy_symlink(fdf, from, &st, fdt, to);
return fd_copy_symlink(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags);
else if (S_ISFIFO(st.st_mode))
return fd_copy_fifo(fdf, from, &st, fdt, to);
return fd_copy_fifo(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags);
else if (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode) || S_ISSOCK(st.st_mode))
return fd_copy_node(fdf, from, &st, fdt, to);
return fd_copy_node(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags);
else
return -EOPNOTSUPP;
}
int copy_tree(const char *from, const char *to, CopyFlags copy_flags) {
return copy_tree_at(AT_FDCWD, from, AT_FDCWD, to, copy_flags);
int copy_tree(const char *from, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags) {
return copy_tree_at(AT_FDCWD, from, AT_FDCWD, to, override_uid, override_gid, copy_flags);
}
int copy_directory_fd(int dirfd, const char *to, CopyFlags copy_flags) {
@@ -420,7 +469,7 @@ int copy_directory_fd(int dirfd, const char *to, CopyFlags copy_flags) {
if (!S_ISDIR(st.st_mode))
return -ENOTDIR;
return fd_copy_directory(dirfd, NULL, &st, AT_FDCWD, to, st.st_dev, copy_flags);
return fd_copy_directory(dirfd, NULL, &st, AT_FDCWD, to, st.st_dev, UID_INVALID, GID_INVALID, copy_flags);
}
int copy_directory(const char *from, const char *to, CopyFlags copy_flags) {
@@ -435,7 +484,7 @@ int copy_directory(const char *from, const char *to, CopyFlags copy_flags) {
if (!S_ISDIR(st.st_mode))
return -ENOTDIR;
return fd_copy_directory(AT_FDCWD, from, &st, AT_FDCWD, to, st.st_dev, copy_flags);
return fd_copy_directory(AT_FDCWD, from, &st, AT_FDCWD, to, st.st_dev, UID_INVALID, GID_INVALID, copy_flags);
}
int copy_file_fd(const char *from, int fdt, CopyFlags copy_flags) {
+2 -2
View File
@@ -33,8 +33,8 @@ typedef enum CopyFlags {
int copy_file_fd(const char *from, int to, CopyFlags copy_flags);
int copy_file(const char *from, const char *to, int open_flags, mode_t mode, unsigned chattr_flags, CopyFlags copy_flags);
int copy_file_atomic(const char *from, const char *to, mode_t mode, unsigned chattr_flags, CopyFlags copy_flags);
int copy_tree(const char *from, const char *to, CopyFlags copy_flags);
int copy_tree_at(int fdf, const char *from, int fdt, const char *to, CopyFlags copy_flags);
int copy_tree(const char *from, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags);
int copy_tree_at(int fdf, const char *from, int fdt, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags);
int copy_directory_fd(int dirfd, const char *to, CopyFlags copy_flags);
int copy_directory(const char *from, const char *to, CopyFlags copy_flags);
int copy_bytes(int fdf, int fdt, uint64_t max_bytes, CopyFlags copy_flags);