From ef9cc1ec63de22707cefdc57da64522376d7dbc2 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Tue, 27 Nov 2018 15:54:17 -0500 Subject: nfsd4: fix crash on writing v4_end_grace before nfsd startup [ Upstream commit 62a063b8e7d1db684db3f207261a466fa3194e72 ] Anatoly Trosinenko reports that this: 1) Checkout fresh master Linux branch (tested with commit e195ca6cb) 2) Copy x84_64-config-4.14 to .config, then enable NFS server v4 and build 3) From `kvm-xfstests shell`: results in NULL dereference in locks_end_grace. Check that nfsd has been started before trying to end the grace period. Reported-by: Anatoly Trosinenko Signed-off-by: J. Bruce Fields Signed-off-by: Sasha Levin --- fs/nfsd/nfsctl.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/nfsd/nfsctl.c') diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 9690cb4dd588..03c7a4e7b6ba 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1106,6 +1106,8 @@ static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size) case 'Y': case 'y': case '1': + if (nn->nfsd_serv) + return -EBUSY; nfsd4_end_grace(nn); break; default: -- cgit v1.2.3 From d18bcfe455106b23aa254d1da0c1a7f39b9b20fe Mon Sep 17 00:00:00 2001 From: Yihao Wu Date: Wed, 6 Mar 2019 21:03:50 +0800 Subject: nfsd: fix wrong check in write_v4_end_grace() commit dd838821f0a29781b185cd8fb8e48d5c177bd838 upstream. Commit 62a063b8e7d1 "nfsd4: fix crash on writing v4_end_grace before nfsd startup" is trying to fix a NULL dereference issue, but it mistakenly checks if the nfsd server is started. So fix it. Fixes: 62a063b8e7d1 "nfsd4: fix crash on writing v4_end_grace before nfsd startup" Cc: stable@vger.kernel.org Reviewed-by: Joseph Qi Signed-off-by: Yihao Wu Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfsctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/nfsd/nfsctl.c') diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 03c7a4e7b6ba..0cd57db5c5af 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1106,7 +1106,7 @@ static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size) case 'Y': case 'y': case '1': - if (nn->nfsd_serv) + if (!nn->nfsd_serv) return -EBUSY; nfsd4_end_grace(nn); break; -- cgit v1.2.3