diff options
| author | Andrei Vagin <avagin@google.com> | 2019-06-03 10:58:38 -0700 |
|---|---|---|
| committer | Shentubot <shentubot@google.com> | 2019-06-03 10:59:46 -0700 |
| commit | 8e926e3f74cef3d04b37c6a68ba5de966e9d9839 (patch) | |
| tree | 65cd28e8f15b58bf337a36aaec18d155f38eefe0 /pkg/sentry/mm | |
| parent | 216da0b733dbed9aad9b2ab92ac75bcb906fd7ee (diff) | |
gvisor: validate a new map region in the mremap syscall
Right now, mremap allows to remap a memory region over MaxUserAddress,
this means that we can change the stub region.
PiperOrigin-RevId: 251266886
Diffstat (limited to 'pkg/sentry/mm')
| -rw-r--r-- | pkg/sentry/mm/syscalls.go | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/pkg/sentry/mm/syscalls.go b/pkg/sentry/mm/syscalls.go index 0368c6794..af1e53f5d 100644 --- a/pkg/sentry/mm/syscalls.go +++ b/pkg/sentry/mm/syscalls.go @@ -470,6 +470,16 @@ func (mm *MemoryManager) MRemap(ctx context.Context, oldAddr usermem.Addr, oldSi return 0, syserror.EINVAL } + // Check that the new region is valid. + _, err := mm.findAvailableLocked(newSize, findAvailableOpts{ + Addr: newAddr, + Fixed: true, + Unmap: true, + }) + if err != nil { + return 0, err + } + // Unmap any mappings at the destination. mm.unmapLocked(ctx, newAR) |