From ec572b9e81b1df79147c2e6f69458e65cf248598 Mon Sep 17 00:00:00 2001 From: Eryu Guan Date: Fri, 29 Sep 2017 15:01:10 +0800 Subject: [PATCH] nfsd4: define nfsd4_secinfo_no_name_release() Commit 34b1744c91cc ("nfsd4: define ->op_release for compound ops") defined a couple ->op_release functions and run them if necessary. But there's a problem with that is that it reused nfsd4_secinfo_release() as the op_release of OP_SECINFO_NO_NAME, and caused a leak on struct nfsd4_secinfo_no_name in nfsd4_encode_secinfo_no_name(), because there's no .si_exp field in struct nfsd4_secinfo_no_name. I found this because I was unable to umount an ext4 partition after exporting it via NFS & run fsstress on the nfs mount. A simplified reproducer would be: # mount a local-fs device at /mnt/test, and export it via NFS with # fsid=0 export option (this is required) mount /dev/sda5 /mnt/test echo "/mnt/test *(rw,no_root_squash,fsid=0)" >> /etc/exports service nfs restart # locally mount the nfs export with all default, note that I have # nfsv4.1 configured as the default nfs version, because of the # fsid export option, v4 mount would fail and fall back to v3 mount localhost:/mnt/test /mnt/nfs # try to umount the underlying device, but got EBUSY umount /mnt/nfs service nfs stop umount /mnt/test <=== EBUSY here Fixed it by defining a separate nfsd4_secinfo_no_name_release() function as the op_release method of OP_SECINFO_NO_NAME that releases the correct nfsd4_secinfo_no_name structure. Fixes: 34b1744c91cc ("nfsd4: define ->op_release for compound ops") Signed-off-by: Eryu Guan Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4proc.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 3c69db7d4905..8487486ec496 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -927,6 +927,13 @@ nfsd4_secinfo_release(union nfsd4_op_u *u) exp_put(u->secinfo.si_exp); } +static void +nfsd4_secinfo_no_name_release(union nfsd4_op_u *u) +{ + if (u->secinfo_no_name.sin_exp) + exp_put(u->secinfo_no_name.sin_exp); +} + static __be32 nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, union nfsd4_op_u *u) @@ -2375,7 +2382,7 @@ static const struct nfsd4_operation nfsd4_ops[] = { }, [OP_SECINFO_NO_NAME] = { .op_func = nfsd4_secinfo_no_name, - .op_release = nfsd4_secinfo_release, + .op_release = nfsd4_secinfo_no_name_release, .op_flags = OP_HANDLES_WRONGSEC, .op_name = "OP_SECINFO_NO_NAME", .op_rsize_bop = nfsd4_secinfo_rsize,