diff options
| author | Eric Biggers <ebiggers@google.com> | 2019-06-12 20:43:13 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2019-06-17 23:36:07 +0200 |
| commit | 1b0b9cc8d3793e31b313e6c9685513b08cd883c4 (patch) | |
| tree | 35a629a4bfb4025cf8a49335d5d3d39dd0187d01 /fs/namespace.c | |
| parent | Linux 5.2-rc5 (diff) | |
| download | linux-1b0b9cc8d3793e31b313e6c9685513b08cd883c4.tar.xz linux-1b0b9cc8d3793e31b313e6c9685513b08cd883c4.zip | |
vfs: fsmount: add missing mntget()
sys_fsmount() needs to take a reference to the new mount when adding it
to the anonymous mount namespace. Otherwise the filesystem can be
unmounted while it's still in use, as found by syzkaller.
Reported-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: syzbot+99de05d099a170867f22@syzkaller.appspotmail.com
Reported-by: syzbot+7008b8b8ba7df475fdc8@syzkaller.appspotmail.com
Fixes: 93766fbd2696 ("vfs: syscall: Add fsmount() to create a mount for a superblock")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namespace.c')
| -rw-r--r-- | fs/namespace.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index b26778bdc236..5dc137a22d40 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -3445,6 +3445,7 @@ SYSCALL_DEFINE3(fsmount, int, fs_fd, unsigned int, flags, ns->root = mnt; ns->mounts = 1; list_add(&mnt->mnt_list, &ns->list); + mntget(newmount.mnt); /* Attach to an apparent O_PATH fd with a note that we need to unmount * it, not just simply put it. |