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| author | Jeff Mahoney <jeffm@suse.com> | 2016-07-05 17:32:30 -0400 |
|---|---|---|
| committer | Andreas Blaesius <skate4life@gmx.de> | 2017-03-17 11:02:52 +0100 |
| commit | e46c80f76c1f23ee3d904202e2a5725a09b9a1de (patch) | |
| tree | 911b435681323e45d4460e406b452fc6c9ad967e | |
| parent | 50821a944cf58e50039b0dc810e73b95cef986d8 (diff) | |
| download | kernel_samsung_espresso10-e46c80f76c1f23ee3d904202e2a5725a09b9a1de.tar.gz kernel_samsung_espresso10-e46c80f76c1f23ee3d904202e2a5725a09b9a1de.tar.bz2 kernel_samsung_espresso10-e46c80f76c1f23ee3d904202e2a5725a09b9a1de.zip | |
ecryptfs: don't allow mmap when the lower fs doesn't support it
There are legitimate reasons to disallow mmap on certain files, notably
in sysfs or procfs. We shouldn't emulate mmap support on file systems
that don't offer support natively.
CVE-2016-1583
Change-Id: I378990d848df48abfe4b58b08cc64e3563577474
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: stable@vger.kernel.org
[tyhicks: clean up f_op check by using ecryptfs_file_to_lower()]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
| -rw-r--r-- | fs/ecryptfs/file.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index d3f95f941c4..a2a97cb614d 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -151,7 +151,15 @@ static const struct vm_operations_struct ecryptfs_file_vm_ops = { static int ecryptfs_file_mmap(struct file *file, struct vm_area_struct *vma) { + struct file *lower_file = ecryptfs_file_to_lower(file); int rc; + /* + * Don't allow mmap on top of file systems that don't support it + * natively. If FILESYSTEM_MAX_STACK_DEPTH > 2 or ecryptfs + * allows recursive mounting, this will need to be extended. + */ + if (!lower_file->f_op->mmap) + return -ENODEV; rc = generic_file_mmap(file, vma); if (!rc) |