diff options
Diffstat (limited to 'pkg/sentry/fs')
| -rw-r--r-- | pkg/sentry/fs/file_overlay.go | 12 | ||||
| -rw-r--r-- | pkg/sentry/fs/fsutil/file.go | 4 | ||||
| -rw-r--r-- | pkg/sentry/fs/fsutil/host_file_mapper.go | 21 |
3 files changed, 30 insertions, 7 deletions
diff --git a/pkg/sentry/fs/file_overlay.go b/pkg/sentry/fs/file_overlay.go index 031cd33ce..a27dd0b9a 100644 --- a/pkg/sentry/fs/file_overlay.go +++ b/pkg/sentry/fs/file_overlay.go @@ -16,6 +16,7 @@ package fs import ( "io" + "math" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/errors/linuxerr" @@ -360,10 +361,13 @@ func (*overlayFileOperations) ConfigureMMap(ctx context.Context, file *File, opt return linuxerr.ENODEV } - // FIXME(jamieliu): This is a copy/paste of fsutil.GenericConfigureMMap, - // which we can't use because the overlay implementation is in package fs, - // so depending on fs/fsutil would create a circular dependency. Move - // overlay to fs/overlay. + // TODO(gvisor.dev/issue/1624): This is a copy/paste of + // fsutil.GenericConfigureMMap, which we can't use because the overlay + // implementation is in package fs, so depending on fs/fsutil would create + // a circular dependency. VFS2 overlay doesn't have this issue. + if opts.Offset+opts.Length > math.MaxInt64 { + return linuxerr.EOVERFLOW + } opts.Mappable = o opts.MappingIdentity = file file.IncRef() diff --git a/pkg/sentry/fs/fsutil/file.go b/pkg/sentry/fs/fsutil/file.go index 3ece73b81..38e3ed42d 100644 --- a/pkg/sentry/fs/fsutil/file.go +++ b/pkg/sentry/fs/fsutil/file.go @@ -16,6 +16,7 @@ package fsutil import ( "io" + "math" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/errors/linuxerr" @@ -210,6 +211,9 @@ func (FileNoMMap) ConfigureMMap(context.Context, *fs.File, *memmap.MMapOpts) err // GenericConfigureMMap implements fs.FileOperations.ConfigureMMap for most // filesystems that support memory mapping. func GenericConfigureMMap(file *fs.File, m memmap.Mappable, opts *memmap.MMapOpts) error { + if opts.Offset+opts.Length > math.MaxInt64 { + return linuxerr.EOVERFLOW + } opts.Mappable = m opts.MappingIdentity = file file.IncRef() diff --git a/pkg/sentry/fs/fsutil/host_file_mapper.go b/pkg/sentry/fs/fsutil/host_file_mapper.go index 23528bf25..37ddb1a3c 100644 --- a/pkg/sentry/fs/fsutil/host_file_mapper.go +++ b/pkg/sentry/fs/fsutil/host_file_mapper.go @@ -93,7 +93,8 @@ func NewHostFileMapper() *HostFileMapper { func (f *HostFileMapper) IncRefOn(mr memmap.MappableRange) { f.refsMu.Lock() defer f.refsMu.Unlock() - for chunkStart := mr.Start &^ chunkMask; chunkStart < mr.End; chunkStart += chunkSize { + chunkStart := mr.Start &^ chunkMask + for { refs := f.refs[chunkStart] pgs := pagesInChunk(mr, chunkStart) if refs+pgs < refs { @@ -101,6 +102,10 @@ func (f *HostFileMapper) IncRefOn(mr memmap.MappableRange) { panic(fmt.Sprintf("HostFileMapper.IncRefOn(%v): adding %d page references to chunk %#x, which has %d page references", mr, pgs, chunkStart, refs)) } f.refs[chunkStart] = refs + pgs + chunkStart += chunkSize + if chunkStart >= mr.End || chunkStart == 0 { + break + } } } @@ -112,7 +117,8 @@ func (f *HostFileMapper) IncRefOn(mr memmap.MappableRange) { func (f *HostFileMapper) DecRefOn(mr memmap.MappableRange) { f.refsMu.Lock() defer f.refsMu.Unlock() - for chunkStart := mr.Start &^ chunkMask; chunkStart < mr.End; chunkStart += chunkSize { + chunkStart := mr.Start &^ chunkMask + for { refs := f.refs[chunkStart] pgs := pagesInChunk(mr, chunkStart) switch { @@ -128,6 +134,10 @@ func (f *HostFileMapper) DecRefOn(mr memmap.MappableRange) { case refs < pgs: panic(fmt.Sprintf("HostFileMapper.DecRefOn(%v): removing %d page references from chunk %#x, which has %d page references", mr, pgs, chunkStart, refs)) } + chunkStart += chunkSize + if chunkStart >= mr.End || chunkStart == 0 { + break + } } } @@ -161,7 +171,8 @@ func (f *HostFileMapper) forEachMappingBlockLocked(fr memmap.FileRange, fd int, if write { prot |= unix.PROT_WRITE } - for chunkStart := fr.Start &^ chunkMask; chunkStart < fr.End; chunkStart += chunkSize { + chunkStart := fr.Start &^ chunkMask + for { m, ok := f.mappings[chunkStart] if !ok { addr, _, errno := unix.Syscall6( @@ -201,6 +212,10 @@ func (f *HostFileMapper) forEachMappingBlockLocked(fr memmap.FileRange, fd int, endOff = fr.End - chunkStart } fn(f.unsafeBlockFromChunkMapping(m.addr).TakeFirst64(endOff).DropFirst64(startOff)) + chunkStart += chunkSize + if chunkStart >= fr.End || chunkStart == 0 { + break + } } return nil } |