android_kernel_oneplus_msm8998/fs/nfsd
J. Bruce Fields 198a54f07f nfsd: allow fh_want_write to be called twice
[ Upstream commit 0b8f62625dc309651d0efcb6a6247c933acd8b45 ]

A fuzzer recently triggered lockdep warnings about potential sb_writers
deadlocks caused by fh_want_write().

Looks like we aren't careful to pair each fh_want_write() with an
fh_drop_write().

It's not normally a problem since fh_put() will call fh_drop_write() for
us.  And was OK for NFSv3 where we'd do one operation that might call
fh_want_write(), and then put the filehandle.

But an NFSv4 protocol fuzzer can do weird things like call unlink twice
in a compound, and then we get into trouble.

I'm a little worried about this approach of just leaving everything to
fh_put().  But I think there are probably a lot of
fh_want_write()/fh_drop_write() imbalances so for now I think we need it
to be more forgiving.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-22 08:18:20 +02:00
..
acl.h
auth.c
auth.h
blocklayout.c
blocklayoutxdr.c
blocklayoutxdr.h
cache.h
current_stateid.h
export.c
export.h
fault_inject.c
idmap.h
Kconfig
lockd.c
Makefile
netns.h
nfs2acl.c
nfs3acl.c
nfs3proc.c nfsd: fix memory corruption caused by readdir 2019-03-23 08:44:39 +01:00
nfs3xdr.c nfsd: fix memory corruption caused by readdir 2019-03-23 08:44:39 +01:00
nfs4acl.c
nfs4callback.c nfsd: Don't release the callback slot unless it was actually held 2019-05-16 19:44:44 +02:00
nfs4idmap.c
nfs4layouts.c
nfs4proc.c nfsd: fix corrupted reply to badly ordered compound 2018-10-10 08:52:07 +02:00
nfs4recover.c
nfs4state.c
nfs4xdr.c
nfscache.c
nfsctl.c nfsd: fix wrong check in write_v4_end_grace() 2019-03-23 08:44:39 +01:00
nfsd.h
nfsfh.c
nfsfh.h
nfsproc.c
nfssvc.c
nfsxdr.c
pnfs.h
state.h nfsd: Don't release the callback slot unless it was actually held 2019-05-16 19:44:44 +02:00
stats.c
stats.h
trace.c
trace.h
vfs.c
vfs.h nfsd: allow fh_want_write to be called twice 2019-06-22 08:18:20 +02:00
xdr.h
xdr3.h
xdr4.h
xdr4cb.h