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author | Jeff Mahoney <jeffm@suse.com> | 2016-07-05 17:32:29 -0400 |
---|---|---|
committer | Sasha Levin <alexander.levin@verizon.com> | 2016-07-19 15:49:44 -0400 |
commit | f1e8b05914912c9a6309c450f266aa21d5667524 (patch) | |
tree | ea7957883e6d6b042c4be85f675fdc9d2d4f24fd | |
parent | 9c9497d5b1e93187ea6c0cdca3f3706fd7713acf (diff) | |
download | lwn-f1e8b05914912c9a6309c450f266aa21d5667524.tar.gz lwn-f1e8b05914912c9a6309c450f266aa21d5667524.zip |
Revert "ecryptfs: forbid opening files without mmap handler"
[ Upstream commit 78c4e172412de5d0456dc00d2b34050aa0b683b5 ]
This reverts commit 2f36db71009304b3f0b95afacd8eba1f9f046b87.
It fixed a local root exploit but also introduced a dependency on
the lower file system implementing an mmap operation just to open a file,
which is a bit of a heavy hammer. The right fix is to have mmap depend
on the existence of the mmap handler instead.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
-rw-r--r-- | fs/ecryptfs/kthread.c | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/fs/ecryptfs/kthread.c b/fs/ecryptfs/kthread.c index e818f5ac7a26..866bb18efefe 100644 --- a/fs/ecryptfs/kthread.c +++ b/fs/ecryptfs/kthread.c @@ -25,7 +25,6 @@ #include <linux/slab.h> #include <linux/wait.h> #include <linux/mount.h> -#include <linux/file.h> #include "ecryptfs_kernel.h" struct ecryptfs_open_req { @@ -148,7 +147,7 @@ int ecryptfs_privileged_open(struct file **lower_file, flags |= IS_RDONLY(d_inode(lower_dentry)) ? O_RDONLY : O_RDWR; (*lower_file) = dentry_open(&req.path, flags, cred); if (!IS_ERR(*lower_file)) - goto have_file; + goto out; if ((flags & O_ACCMODE) == O_RDONLY) { rc = PTR_ERR((*lower_file)); goto out; @@ -166,16 +165,8 @@ int ecryptfs_privileged_open(struct file **lower_file, mutex_unlock(&ecryptfs_kthread_ctl.mux); wake_up(&ecryptfs_kthread_ctl.wait); wait_for_completion(&req.done); - if (IS_ERR(*lower_file)) { + if (IS_ERR(*lower_file)) rc = PTR_ERR(*lower_file); - goto out; - } -have_file: - if ((*lower_file)->f_op->mmap == NULL) { - fput(*lower_file); - *lower_file = NULL; - rc = -EMEDIUMTYPE; - } out: return rc; } |