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| author | Nicolas Lacasse <nlacasse@google.com> | 2019-07-01 15:24:18 -0700 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2019-07-01 15:25:22 -0700 |
| commit | 06537129a67cbdced394f514a7d2399c19082f47 (patch) | |
| tree | 2c925f789c745f661c4000c4084309144ea576ad /pkg/sentry/syscalls | |
| parent | 3446f4e29bd547e5576caf16d8c2bb45560439e9 (diff) | |
Check remaining traversal limit when creating a file through a symlink.
This fixes the case when an app tries to create a file that already exists, and
is a symlink to itself. A test was added.
PiperOrigin-RevId: 256044811
Diffstat (limited to 'pkg/sentry/syscalls')
| -rw-r--r-- | pkg/sentry/syscalls/linux/sys_file.go | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/pkg/sentry/syscalls/linux/sys_file.go b/pkg/sentry/syscalls/linux/sys_file.go index 3ef7441c2..3410af69c 100644 --- a/pkg/sentry/syscalls/linux/sys_file.go +++ b/pkg/sentry/syscalls/linux/sys_file.go @@ -354,6 +354,12 @@ func createAt(t *kernel.Task, dirFD kdefs.FD, addr usermem.Addr, flags uint, mod break } + // Are we able to resolve further? + if remainingTraversals == 0 { + found.DecRef() + return syscall.ELOOP + } + // Resolve the symlink to a path via Readlink. path, err := found.Inode.Readlink(t) if err != nil { |