linux/fs/fuse
Miklos Szeredi 9fa248c65b fuse: fix readdir cache race
There's a race in fuse's readdir cache that can result in an uninitilized
page being read.  The page lock is supposed to prevent this from happening
but in the following case it doesn't:

Two fuse_add_dirent_to_cache() start out and get the same parameters
(size=0,offset=0).  One of them wins the race to create and lock the page,
after which it fills in data, sets rdc.size and unlocks the page.

In the meantime the page gets evicted from the cache before the other
instance gets to run.  That one also creates the page, but finds the
size to be mismatched, bails out and leaves the uninitialized page in the
cache.

Fix by marking a filled page uptodate and ignoring non-uptodate pages.

Reported-by: Frank Sorenson <fsorenso@redhat.com>
Fixes: 5d7bc7e868 ("fuse: allow using readdir cache")
Cc: <stable@vger.kernel.org> # v4.20
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2022-10-20 17:18:58 +02:00
..
acl.c vfs: add rcu argument to ->get_acl() callback 2021-08-18 22:08:24 +02:00
control.c fuse: Remove the control interface for virtio-fs 2022-07-21 16:06:19 +02:00
cuse.c cuse: simplify refcount 2021-04-14 10:40:58 +02:00
dax.c fuse: avoid unnecessary spinlock bump 2022-07-21 16:02:45 +02:00
dev.c mm: multi-gen LRU: groundwork 2022-09-26 19:46:09 -07:00
dir.c fuse: implement ->tmpfile() 2022-09-24 07:00:00 +02:00
file.c iov_iter stuff, part 2, rebased 2022-08-08 20:04:35 -07:00
fuse_i.h fuse: implement ->tmpfile() 2022-09-24 07:00:00 +02:00
inode.c fuse: retire block-device-based superblock on force unmount 2022-07-27 11:30:31 +02:00
ioctl.c fuse: ioctl: translate ENOSYS 2022-07-21 16:06:18 +02:00
Kconfig dax: remove CONFIG_DAX_DRIVER 2021-12-04 08:58:51 -08:00
Makefile fuse: move ioctl to separate source file 2021-04-12 15:04:30 +02:00
readdir.c fuse: fix readdir cache race 2022-10-20 17:18:58 +02:00
virtio_fs.c virtio_fs: Modify format for virtio_fs_direct_access 2022-07-26 10:38:58 +02:00
xattr.c fuse: move fuse_invalidate_attr() into fuse_update_ctime() 2021-10-22 17:03:01 +02:00