diff options
| author | Jeff Mahoney <jeffm@suse.com> | 2016-07-05 17:32:30 -0400 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2016-07-20 11:35:52 -0400 |
| commit | 8c8e669bb8c5f690976883dd3b7a32d605c58d9a (patch) | |
| tree | cb314be772fb025fb5025792ebab87361a1daf4b | |
| parent | 050216f65a9d2caa4385996a4a226c1b6f4969f7 (diff) | |
ecryptfs: don't allow mmap when the lower fs doesn't support it
[ Upstream commit f0fe970df3838c202ef6c07a4c2b36838ef0a88b ]
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
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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
| -rw-r--r-- | fs/ecryptfs/file.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index 77a3db3791c7..c02f52cfe64a 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -177,6 +177,19 @@ out: return rc; } +static int ecryptfs_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct file *lower_file = ecryptfs_file_to_lower(file); + /* + * 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; + return generic_file_mmap(file, vma); +} + /** * ecryptfs_open * @inode: inode speciying file to open @@ -374,7 +387,7 @@ const struct file_operations ecryptfs_main_fops = { #ifdef CONFIG_COMPAT .compat_ioctl = ecryptfs_compat_ioctl, #endif - .mmap = generic_file_mmap, + .mmap = ecryptfs_mmap, .open = ecryptfs_open, .flush = ecryptfs_flush, .release = ecryptfs_release, |