mirror/syncthing
1
0
Fork 0
mirror of https://github.com/syncthing/syncthing.git synced 2026-06-23 16:10:33 -04:00
Code Issues Packages Projects Releases Wiki Activity

fix(fs, model): improve symlink resilience in file shortcut (#10739)

Browse Source 
Ensure file was a file before the shortcut as well as after... (This was
implied when talking to a correct implementation, but not enforced.)

Make our file opening operations safe by default by ensuring the last
path component is not a symlink.

---------

Signed-off-by: Jakob Borg <jakob@kastelo.net>
This commit is contained in:
Jakob Borg
2026-06-11 18:50:11 +02:00
committed by GitHub
parent 5dbf809a4c
commit a5cbeeafea
4 changed files with 9 additions and 19 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
lib/fs/basicfs.go
View File

@@ -241,15 +241,7 @@ func (f *BasicFilesystem) DirNames(name string) ([]string, error) {
}
func (f *BasicFilesystem) Open(name string) (File, error) {
rootedName, err := f.rooted(name)
if err != nil {
return nil, err
}
fd, err := os.Open(rootedName)
if err != nil {
return nil, err
}
return basicFile{fd, name}, err
return f.OpenFile(name, os.O_RDONLY, 0)
}
func (f *BasicFilesystem) OpenFile(name string, flags int, mode FileMode) (File, error) {
@@ -257,6 +249,7 @@ func (f *BasicFilesystem) OpenFile(name string, flags int, mode FileMode) (File,
if err != nil {
return nil, err
}
flags |= alwaysOpenFlags // enforce extra bits in flags
fd, err := os.OpenFile(rootedName, flags, os.FileMode(mode))
if err != nil {
return nil, err
@@ -265,15 +258,7 @@ func (f *BasicFilesystem) OpenFile(name string, flags int, mode FileMode) (File,
}
func (f *BasicFilesystem) Create(name string) (File, error) {
rootedName, err := f.rooted(name)
if err != nil {
return nil, err
}
fd, err := os.Create(rootedName)
if err != nil {
return nil, err
}
return basicFile{fd, name}, err
return f.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o666)
}
func (*BasicFilesystem) Walk(_ string, _ WalkFunc) error {

3
lib/fs/basicfs_unix.go
View File

@@ -14,8 +14,11 @@ import (
"path/filepath"
"strconv"
"strings"
"syscall"
)
const alwaysOpenFlags = syscall.O_NOFOLLOW // never open symlinks as the final path component
func (f *BasicFilesystem) CreateSymlink(target, name string) error {
name, err := f.rooted(name)
if err != nil {

2
lib/fs/basicfs_windows.go
View File

@@ -21,6 +21,8 @@ import (
"golang.org/x/sys/windows"
)
const alwaysOpenFlags = 0 // no extra flags
var errNotSupported = errors.New("symlinks not supported")
func (BasicFilesystem) ReadSymlink(path string) (string, error) {

2
lib/model/folder_sendrecv.go
View File

@@ -382,7 +382,7 @@ loop:
if err != nil {
return nil, nil, err
}
if hasCurFile && file.BlocksEqual(curFile) {
if hasCurFile && curFile.Type == file.Type && file.BlocksEqual(curFile) {
// We are supposed to copy the entire file, and then fetch nothing. We
// are only updating metadata, so we don't actually *need* to make the
// copy.