linux-stable.git/fs/ceph, branch v4.19.166

ceph: fix race in concurrent __ceph_remove_cap invocations

2020-12-30T10:26:13+00:00

commit e5cafce3ad0f8652d6849314d951459c2bff7233 upstream.

A NULL pointer dereference may occur in __ceph_remove_cap with some of the
callbacks used in ceph_iterate_session_caps, namely trim_caps_cb and
remove_session_caps_cb. Those callers hold the session->s_mutex, so they
are prevented from concurrent execution, but ceph_evict_inode does not.

Since the callers of this function hold the i_ceph_lock, the fix is simply
a matter of returning immediately if caps->ci is NULL.

Cc: stable@vger.kernel.org
URL: https://tracker.ceph.com/issues/43272
Suggested-by: Jeff Layton 
Signed-off-by: Luis Henriques 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Greg Kroah-Hartman

ceph: promote to unsigned long long before shifting

2020-11-05T10:08:53+00:00

commit c403c3a2fbe24d4ed33e10cabad048583ebd4edf upstream.

On 32-bit systems, this shift will overflow for files larger than 4GB.

Cc: stable@vger.kernel.org
Fixes: 61f68816211e ("ceph: check caps in filemap_fault and page_mkwrite")
Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Greg Kroah-Hartman

ceph: fix potential race in ceph_check_caps

2020-10-01T11:14:47+00:00

[ Upstream commit dc3da0461cc4b76f2d0c5b12247fcb3b520edbbf ]

Nothing ensures that session will still be valid by the time we
dereference the pointer. Take and put a reference.

In principle, we should always be able to get a reference here, but
throw a warning if that's ever not the case.

Signed-off-by: Jeff Layton 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Sasha Levin

ceph: ensure we have a new cap before continuing in fill_inode

2020-10-01T11:14:31+00:00

[ Upstream commit 9a6bed4fe0c8bf57785cbc4db9f86086cb9b193d ]

If the caller passes in a NULL cap_reservation, and we can't allocate
one then ensure that we fail gracefully.

Signed-off-by: Jeff Layton 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Sasha Levin

ceph: don't allow setlease on cephfs

2020-09-09T17:04:23+00:00

[ Upstream commit 496ceaf12432b3d136dcdec48424312e71359ea7 ]

Leases don't currently work correctly on kcephfs, as they are not broken
when caps are revoked. They could eventually be implemented similarly to
how we did them in libcephfs, but for now don't allow them.

[ idryomov: no need for simple_nosetlease() in ceph_dir_fops and
  ceph_snapdir_fops ]

Signed-off-by: Jeff Layton 
Reviewed-by: Ilya Dryomov 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Sasha Levin

ceph: fix potential mdsc use-after-free crash

2020-09-03T09:24:22+00:00

[ Upstream commit fa9967734227b44acb1b6918033f9122dc7825b9 ]

Make sure the delayed work stopped before releasing the resources.

cancel_delayed_work_sync() will only guarantee that the work finishes
executing if the work is already in the ->worklist.  That means after
the cancel_delayed_work_sync() returns, it will leave the work requeued
if it was rearmed at the end. That can lead to a use after free once the
work struct is freed.

Fix it by flushing the delayed work instead of trying to cancel it, and
ensure that the work doesn't rearm if the mdsc is stopping.

URL: https://tracker.ceph.com/issues/46293
Signed-off-by: Xiubo Li 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Sasha Levin

ceph: fix use-after-free for fsc->mdsc

2020-08-26T08:31:01+00:00

[ Upstream commit a7caa88f8b72c136f9a401f498471b8a8e35370d ]

If the ceph_mdsc_init() fails, it will free the mdsc already.

Reported-by: syzbot+b57f46d8d6ea51960b8c@syzkaller.appspotmail.com
Signed-off-by: Xiubo Li 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Sasha Levin

ceph: fix double unlock in handle_cap_export()

2020-05-27T15:37:34+00:00

[ Upstream commit 4d8e28ff3106b093d98bfd2eceb9b430c70a8758 ]

If the ceph_mdsc_open_export_target_session() return fails, it will
do a "goto retry", but the session mutex has already been unlocked.
Re-lock the mutex in that case to ensure that we don't unlock it
twice.

Signed-off-by: Wu Bo 
Reviewed-by: "Yan, Zheng" 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Sasha Levin

ceph: don't skip updating wanted caps when cap is stale

2020-04-29T14:31:11+00:00

[ Upstream commit 0aa971b6fd3f92afef6afe24ef78d9bb14471519 ]

1. try_get_cap_refs() fails to get caps and finds that mds_wanted
   does not include what it wants. It returns -ESTALE.
2. ceph_get_caps() calls ceph_renew_caps(). ceph_renew_caps() finds
   that inode has cap, so it calls ceph_check_caps().
3. ceph_check_caps() finds that issued caps (without checking if it's
   stale) already includes caps wanted by open file, so it skips
   updating wanted caps.

Above events can cause an infinite loop inside ceph_get_caps().

Signed-off-by: "Yan, Zheng" 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Sasha Levin

ceph: return ceph_mdsc_do_request() errors from __get_parent()

2020-04-29T14:31:10+00:00

[ Upstream commit c6d50296032f0b97473eb2e274dc7cc5d0173847 ]

Return the error returned by ceph_mdsc_do_request(). Otherwise,
r_target_inode ends up being NULL this ends up returning ENOENT
regardless of the error.

Signed-off-by: Qiujun Huang 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Sasha Levin