linux-toradex.git/fs/fuse, branch v4.9.62

fuse: fix READDIRPLUS skipping an entry

2017-11-02T08:49:13+00:00

commit c6cdd51404b7ac12dd95173ddfc548c59ecf037f upstream.

Marios Titas running a Haskell program noticed a problem with fuse's
readdirplus: when it is interrupted by a signal, it skips one directory
entry.

The reason is that fuse erronously updates ctx->pos after a failed
dir_emit().

The issue originates from the patch adding readdirplus support.

Reported-by: Jakob Unterwurzacher 
Tested-by: Marios Titas 
Signed-off-by: Miklos Szeredi 
Fixes: 0b05b18381ee ("fuse: implement NFS-like readdirplus support")
Signed-off-by: Greg Kroah-Hartman

fuse: initialize the flock flag in fuse_file on allocation

2017-08-16T20:43:17+00:00

commit 68227c03cba84a24faf8a7277d2b1a03c8959c2c upstream.

Before the patch, the flock flag could remain uninitialized for the
lifespan of the fuse_file allocation. Unless set to true in
fuse_file_flock(), it would remain in an indeterminate state until read in
an if statement in fuse_release_common(). This could consequently lead to
taking an unexpected branch in the code.

The bug was discovered by a runtime instrumentation designed to detect use
of uninitialized memory in the kernel.

Signed-off-by: Mateusz Jurczyk 
Fixes: 37fb3a30b462 ("fuse: fix flock")
Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

fuse: add missing FR_FORCE

2017-03-12T05:41:47+00:00

commit 2e38bea99a80eab408adee27f873a188d57b76cb upstream.

fuse_file_put() was missing the "force" flag for the RELEASE request when
sending synchronously (fuseblk).

If this flag is not set, then a sync request may be interrupted before it
is dequeued by the userspace filesystem.  In this case the OPEN won't be
balanced with a RELEASE.

Signed-off-by: Miklos Szeredi 
Fixes: 5a18ec176c93 ("fuse: fix hang of single threaded fuseblk filesystem")
Signed-off-by: Greg Kroah-Hartman

fuse: fix uninitialized flags in pipe_buffer

2017-02-23T16:44:35+00:00

commit 84588a93d097bace24b9233930f82511d4f34210 upstream.

Signed-off-by: Miklos Szeredi 
Fixes: d82718e348fe ("fuse_dev_splice_read(): switch to add_to_pipe()")
Signed-off-by: Greg Kroah-Hartman

fuse: fix use after free issue in fuse_dev_do_read()

2017-02-23T16:44:35+00:00

commit 6ba4d2722d06960102c981322035239cd66f7316 upstream.

There is a potential race between fuse_dev_do_write()
and request_wait_answer() contexts as shown below:

TASK 1:
__fuse_request_send():
  |--spin_lock(&fiq->waitq.lock);
  |--queue_request();
  |--spin_unlock(&fiq->waitq.lock);
  |--request_wait_answer():
       |--if (test_bit(FR_SENT, &req->flags))
       
                                   TASK 2:
                                   fuse_dev_do_write():
                                     |--clears bit FR_SENT,
                                     |--request_end():
                                        |--sets bit FR_FINISHED
                                        |--spin_lock(&fiq->waitq.lock);
                                        |--list_del_init(&req->intr_entry);
                                        |--spin_unlock(&fiq->waitq.lock);
                                        |--fuse_put_request();
       |--queue_interrupt();
       
            |--wake_up_locked(&fiq->waitq);
       |--wait_event_freezable();
       

Now, the next fuse_dev_do_read(), see interrupts list is not empty
and then calls fuse_read_interrupt() which tries to access the request
which is already free'd and gets the below crash:

[11432.401266] Unable to handle kernel paging request at virtual address
6b6b6b6b6b6b6b6b
...
[11432.418518] Kernel BUG at ffffff80083720e0
[11432.456168] PC is at __list_del_entry+0x6c/0xc4
[11432.463573] LR is at fuse_dev_do_read+0x1ac/0x474
...
[11432.679999] [] __list_del_entry+0x6c/0xc4
[11432.687794] [] fuse_dev_do_read+0x1ac/0x474
[11432.693180] [] fuse_dev_read+0x6c/0x78
[11432.699082] [] __vfs_read+0xc0/0xe8
[11432.704459] [] vfs_read+0x90/0x108
[11432.709406] [] SyS_read+0x58/0x94

As FR_FINISHED bit is set before deleting the intr_entry with input
queue lock in request completion path, do the testing of this flag and
queueing atomically with the same lock in queue_interrupt().

Signed-off-by: Sahitya Tummala 
Signed-off-by: Miklos Szeredi 
Fixes: fd22d62ed0c3 ("fuse: no fc->lock for iqueue parts")
Signed-off-by: Greg Kroah-Hartman

fuse: fix time_to_jiffies nsec sanity check

2017-01-26T07:24:38+00:00

commit 210675270caa33253e4c33f3c5e657e7d6060812 upstream.

Commit bcb6f6d2b9c2 ("fuse: use timespec64") introduced clamped nsec values
in time_to_jiffies but used the max of nsec and NSEC_PER_SEC - 1 instead of
the min. Because of this, dentries would stay in the cache longer than
requested and go stale in scenarios that relied on their timely eviction.

Fixes: bcb6f6d2b9c2 ("fuse: use timespec64")
Signed-off-by: David Sheets 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

fuse: clear FR_PENDING flag when moving requests out of pending queue

2017-01-26T07:24:38+00:00

commit a8a86d78d673b1c99fe9b0064739fde9e9774184 upstream.

fuse_abort_conn() moves requests from pending list to a temporary list
before canceling them. This operation races with request_wait_answer()
which also tries to remove the request after it gets a fatal signal. It
checks FR_PENDING flag to determine whether the request is still in the
pending list.

Make fuse_abort_conn() clear FR_PENDING flag so that request_wait_answer()
does not remove the request from temporary list.

This bug causes an Oops when trying to delete an already deleted list entry
in end_requests().

Fixes: ee314a870e40 ("fuse: abort: no fc->lock needed for request ending")
Signed-off-by: Tahsin Erdogan 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

fuse: fix clearing suid, sgid for chown()

2016-12-06T15:18:45+00:00

Basically, the pjdfstests set the ownership of a file to 06555, and then
chowns it (as root) to a new uid/gid. Prior to commit a09f99eddef4 ("fuse:
fix killing s[ug]id in setattr"), fuse would send down a setattr with both
the uid/gid change and a new mode.  Now, it just sends down the uid/gid
change.

Technically this is NOTABUG, since POSIX doesn't _require_ that we clear
these bits for a privileged process, but Linux (wisely) has done that and I
think we don't want to change that behavior here.

This is caused by the use of should_remove_suid(), which will always return
0 when the process has CAP_FSETID.

In fact we really don't need to be calling should_remove_suid() at all,
since we've already been indicated that we should remove the suid, we just
don't want to use a (very) stale mode for that.

This patch should fix the above as well as simplify the logic.

Reported-by: Jeff Layton  
Signed-off-by: Miklos Szeredi 
Fixes: a09f99eddef4 ("fuse: fix killing s[ug]id in setattr")
Cc: 
Reviewed-by: Jeff Layton

fuse: fix fuse_write_end() if zero bytes were copied

2016-11-15T11:34:21+00:00

If pos is at the beginning of a page and copied is zero then page is not
zeroed but is marked uptodate.

Fix by skipping everything except unlock/put of page if zero bytes were
copied.

Reported-by: Al Viro 
Fixes: 6b12c1b37e55 ("fuse: Implement write_begin/write_end callbacks")
Cc:  # v3.15+
Signed-off-by: Miklos Szeredi

fuse: fix root dentry initialization

2016-10-18T13:36:48+00:00

Add missing dentry initialization to root dentry.

Fixes: f75fdf22b0a8 ("fuse: don't use ->d_time")
Reported-by: Andreas Reis 
Signed-off-by: Miklos Szeredi