* [patch v2] fs: umount on symlinlk leaks mnt count @ 2014-07-20 7:32 Vasily Averin 2014-07-20 10:48 ` Richard Weinberger 0 siblings, 1 reply; 7+ messages in thread From: Vasily Averin @ 2014-07-20 7:32 UTC (permalink / raw) To: Alexander Viro, linux-fsdevel, linux-kernel [-- Attachment #1: Type: text/plain, Size: 563 bytes --] v2: mntget(path->mnt) should not be called if mountpoint_last() returns 1. Currently umount on symlink blocks following umount: /vz is separate mount # ls /vz/ -al | grep test drwxr-xr-x. 2 root root 4096 Jul 19 01:14 testdir lrwxrwxrwx. 1 root root 11 Jul 19 01:16 testlink -> /vz/testdir # umount -l /vz/testlink umount: /vz/testlink: not mounted (expected) # lsof /vz # umount /vz umount: /vz: device is busy. (unexpected) In this case mountpoint_last() gets an extra refcount on path->mnt Signed-off-by: Vasily Averin <vvs@openvz.org> [-- Attachment #2: diff-umount-symlink-ms-2 --] [-- Type: text/plain, Size: 372 bytes --] diff --git a/fs/namei.c b/fs/namei.c index 985c6f3..9eb787e 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2256,9 +2256,10 @@ done: goto out; } path->dentry = dentry; - path->mnt = mntget(nd->path.mnt); + path->mnt = nd->path.mnt; if (should_follow_link(dentry, nd->flags & LOOKUP_FOLLOW)) return 1; + mntget(path->mnt); follow_mount(path); error = 0; out: ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [patch v2] fs: umount on symlinlk leaks mnt count 2014-07-20 7:32 [patch v2] fs: umount on symlinlk leaks mnt count Vasily Averin @ 2014-07-20 10:48 ` Richard Weinberger [not found] ` <cover.1405859651.git.vvs@openvz.org> 0 siblings, 1 reply; 7+ messages in thread From: Richard Weinberger @ 2014-07-20 10:48 UTC (permalink / raw) To: Vasily Averin; +Cc: Alexander Viro, linux-fsdevel, LKML On Sun, Jul 20, 2014 at 9:32 AM, Vasily Averin <vvs@parallels.com> wrote: > v2: mntget(path->mnt) should not be called if mountpoint_last() returns 1. > > Currently umount on symlink blocks following umount: > > /vz is separate mount > > # ls /vz/ -al | grep test > drwxr-xr-x. 2 root root 4096 Jul 19 01:14 testdir > lrwxrwxrwx. 1 root root 11 Jul 19 01:16 testlink -> /vz/testdir > > # umount -l /vz/testlink > umount: /vz/testlink: not mounted (expected) > > # lsof /vz > # umount /vz > umount: /vz: device is busy. (unexpected) > > In this case mountpoint_last() gets an extra refcount on path->mnt > > Signed-off-by: Vasily Averin <vvs@openvz.org> Sounds reasonable to me. Can you please send the patch inline and not as attachment? -- Thanks, //richard ^ permalink raw reply [flat|nested] 7+ messages in thread
[parent not found: <cover.1405859651.git.vvs@openvz.org>]
* [PATCH v3] fs: umount on symlink leaks mnt count [not found] ` <cover.1405859651.git.vvs@openvz.org> @ 2014-07-20 12:38 ` Vasily Averin 2014-07-21 8:30 ` [PATCH v4] " Vasily Averin 1 sibling, 0 replies; 7+ messages in thread From: Vasily Averin @ 2014-07-20 12:38 UTC (permalink / raw) To: Alexander Viro, linux-fsdevel, linux-kernel, Richard Weinberger v3: patch inline Currently umount on symlink blocks following umount: /vz is separate mount drwxr-xr-x. 2 root root 4096 Jul 19 01:14 testdir lrwxrwxrwx. 1 root root 11 Jul 19 01:16 testlink -> /vz/testdir umount: /vz/testlink: not mounted (expected) umount: /vz: device is busy. (unexpected) In this case mountpoint_last() gets an extra refcount on path->mnt Signed-off-by: Vasily Averin <vvs@openvz.org> --- fs/namei.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 985c6f3..9eb787e 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2256,9 +2256,10 @@ done: goto out; } path->dentry = dentry; - path->mnt = mntget(nd->path.mnt); + path->mnt = nd->path.mnt; if (should_follow_link(dentry, nd->flags & LOOKUP_FOLLOW)) return 1; + mntget(path->mnt); follow_mount(path); error = 0; out: -- 1.7.5.4 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v4] fs: umount on symlink leaks mnt count [not found] ` <cover.1405859651.git.vvs@openvz.org> 2014-07-20 12:38 ` [PATCH v3] fs: umount on symlink " Vasily Averin @ 2014-07-21 8:30 ` Vasily Averin 2014-07-21 12:10 ` Jeff Layton 2014-07-23 6:06 ` Ian Kent 1 sibling, 2 replies; 7+ messages in thread From: Vasily Averin @ 2014-07-21 8:30 UTC (permalink / raw) To: Alexander Viro, linux-fsdevel, linux-kernel, Richard Weinberger v4: description corrected v3: patch inline Currently umount on symlink blocks following umount: /vz is separate mount # ls /vz/ -al | grep test drwxr-xr-x. 2 root root 4096 Jul 19 01:14 testdir lrwxrwxrwx. 1 root root 11 Jul 19 01:16 testlink -> /vz/testdir # umount -l /vz/testlink umount: /vz/testlink: not mounted (expected) # lsof /vz # umount /vz umount: /vz: device is busy. (unexpected) In this case mountpoint_last() gets an extra refcount on path->mnt Signed-off-by: Vasily Averin <vvs@openvz.org> --- fs/namei.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 985c6f3..9eb787e 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2256,9 +2256,10 @@ done: goto out; } path->dentry = dentry; - path->mnt = mntget(nd->path.mnt); + path->mnt = nd->path.mnt; if (should_follow_link(dentry, nd->flags & LOOKUP_FOLLOW)) return 1; + mntget(path->mnt); follow_mount(path); error = 0; out: -- 1.7.5.4 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v4] fs: umount on symlink leaks mnt count 2014-07-21 8:30 ` [PATCH v4] " Vasily Averin @ 2014-07-21 12:10 ` Jeff Layton 2014-07-23 6:06 ` Ian Kent 1 sibling, 0 replies; 7+ messages in thread From: Jeff Layton @ 2014-07-21 12:10 UTC (permalink / raw) To: Vasily Averin Cc: Alexander Viro, linux-fsdevel, linux-kernel, Richard Weinberger On Mon, 21 Jul 2014 12:30:23 +0400 Vasily Averin <vvs@parallels.com> wrote: > v4: description corrected > v3: patch inline > > Currently umount on symlink blocks following umount: > > /vz is separate mount > > # ls /vz/ -al | grep test > drwxr-xr-x. 2 root root 4096 Jul 19 01:14 testdir > lrwxrwxrwx. 1 root root 11 Jul 19 01:16 testlink -> /vz/testdir > # umount -l /vz/testlink > umount: /vz/testlink: not mounted (expected) > > # lsof /vz > # umount /vz > umount: /vz: device is busy. (unexpected) > > In this case mountpoint_last() gets an extra refcount on path->mnt > > Signed-off-by: Vasily Averin <vvs@openvz.org> > --- > fs/namei.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/fs/namei.c b/fs/namei.c > index 985c6f3..9eb787e 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -2256,9 +2256,10 @@ done: > goto out; > } > path->dentry = dentry; > - path->mnt = mntget(nd->path.mnt); > + path->mnt = nd->path.mnt; > if (should_follow_link(dentry, nd->flags & LOOKUP_FOLLOW)) > return 1; > + mntget(path->mnt); > follow_mount(path); > error = 0; > out: Looks correct, I think... Acked-by: -- Jeff Layton <jlayton@primarydata.com> ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v4] fs: umount on symlink leaks mnt count 2014-07-21 8:30 ` [PATCH v4] " Vasily Averin 2014-07-21 12:10 ` Jeff Layton @ 2014-07-23 6:06 ` Ian Kent 2014-07-24 5:59 ` Vasily Averin 1 sibling, 1 reply; 7+ messages in thread From: Ian Kent @ 2014-07-23 6:06 UTC (permalink / raw) To: Vasily Averin Cc: Alexander Viro, linux-fsdevel, linux-kernel, Richard Weinberger On Mon, 2014-07-21 at 12:30 +0400, Vasily Averin wrote: > v4: description corrected > v3: patch inline > > Currently umount on symlink blocks following umount: > > /vz is separate mount > > # ls /vz/ -al | grep test > drwxr-xr-x. 2 root root 4096 Jul 19 01:14 testdir > lrwxrwxrwx. 1 root root 11 Jul 19 01:16 testlink -> /vz/testdir > # umount -l /vz/testlink > umount: /vz/testlink: not mounted (expected) > > # lsof /vz > # umount /vz > umount: /vz: device is busy. (unexpected) > > In this case mountpoint_last() gets an extra refcount on path->mnt > > Signed-off-by: Vasily Averin <vvs@openvz.org> Acked-by: Ian Kent <raven@themaw.net> I was working on this too. I prefer this patch over my own. Haven't tested it yet but it is very similar to the patch I was working with which had seen some basic testing. > --- > fs/namei.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/fs/namei.c b/fs/namei.c > index 985c6f3..9eb787e 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -2256,9 +2256,10 @@ done: > goto out; > } > path->dentry = dentry; > - path->mnt = mntget(nd->path.mnt); > + path->mnt = nd->path.mnt; > if (should_follow_link(dentry, nd->flags & LOOKUP_FOLLOW)) > return 1; > + mntget(path->mnt); > follow_mount(path); > error = 0; > out: ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v4] fs: umount on symlink leaks mnt count 2014-07-23 6:06 ` Ian Kent @ 2014-07-24 5:59 ` Vasily Averin 0 siblings, 0 replies; 7+ messages in thread From: Vasily Averin @ 2014-07-24 5:59 UTC (permalink / raw) Cc: Alexander Viro, linux-fsdevel, linux-kernel, Richard Weinberger CVE-2014-5045 was assigned for this issue On 07/23/2014 10:06 AM, Ian Kent wrote: > On Mon, 2014-07-21 at 12:30 +0400, Vasily Averin wrote: >> Currently umount on symlink blocks following umount: >> >> /vz is separate mount >> >> # ls /vz/ -al | grep test >> drwxr-xr-x. 2 root root 4096 Jul 19 01:14 testdir >> lrwxrwxrwx. 1 root root 11 Jul 19 01:16 testlink -> /vz/testdir >> # umount -l /vz/testlink >> umount: /vz/testlink: not mounted (expected) >> >> # lsof /vz >> # umount /vz >> umount: /vz: device is busy. (unexpected) >> >> In this case mountpoint_last() gets an extra refcount on path->mnt >> >> Signed-off-by: Vasily Averin <vvs@openvz.org> > > Acked-by: Ian Kent <raven@themaw.net> ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2014-07-24 6:00 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-07-20 7:32 [patch v2] fs: umount on symlinlk leaks mnt count Vasily Averin
2014-07-20 10:48 ` Richard Weinberger
[not found] ` <cover.1405859651.git.vvs@openvz.org>
2014-07-20 12:38 ` [PATCH v3] fs: umount on symlink " Vasily Averin
2014-07-21 8:30 ` [PATCH v4] " Vasily Averin
2014-07-21 12:10 ` Jeff Layton
2014-07-23 6:06 ` Ian Kent
2014-07-24 5:59 ` Vasily Averin
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox