[PATCH RESEND 0/5] cachefiles: some bugfixes for withdraw and xattr

[libaokun at huaweicloud.com]

From: Baokun Li <libaokun1 at huawei.com>

Hi all!

There are some fixes for some cachefiles generic processes. We found these
issues when testing the on-demand mode, but the non-on-demand mode is also
involved. The following is a brief overview of the patches, see the patches
for more details.

Patch 1-2: Add fscache_try_get_volume() helper function to avoid
fscache_volume use-after-free on cache withdrawal.

Patch 3: Fix cachefiles_lookup_cookie() and cachefiles_withdraw_cache()
concurrency causing cachefiles_volume use-after-free.

Patch 4-5: Propagate error codes returned by vfs_getxattr() to avoid
endless loops.

Comments and questions are, as always, welcome.

Thanks,
Baokun

Baokun Li (5):
  netfs, fscache: export fscache_put_volume() and add
    fscache_try_get_volume()
  cachefiles: fix slab-use-after-free in fscache_withdraw_volume()
  cachefiles: fix slab-use-after-free in cachefiles_withdraw_cookie()
  cachefiles: correct the return value of
    cachefiles_check_volume_xattr()
  cachefiles: correct the return value of cachefiles_check_auxdata()

 fs/cachefiles/cache.c          | 45 +++++++++++++++++++++++++++++++++-
 fs/cachefiles/volume.c         |  1 -
 fs/cachefiles/xattr.c          |  5 +++-
 fs/netfs/fscache_volume.c      | 14 +++++++++++
 fs/netfs/internal.h            |  2 --
 include/linux/fscache-cache.h  |  6 +++++
 include/trace/events/fscache.h |  4 +++
 7 files changed, 72 insertions(+), 5 deletions(-)

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2.39.2