5.10-stable review patch. If anyone has any objections, please let me know.
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From: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp
[ Upstream commit bd86c69dae65de30f6d47249418ba7889809e31a ]
syzbot is reporting UAF read at register_shrinker_prepared() [1], for commit 7746b32f467b3813 ("NFSD: add shrinker to reap courtesy clients on low memory condition") missed that nfsd4_leases_net_shutdown() from nfsd_exit_net() is called only when nfsd_init_net() succeeded. If nfsd_init_net() fails due to nfsd_reply_cache_init() failure, register_shrinker() from nfsd4_init_leases_net() has to be undone before nfsd_init_net() returns.
Link: https://syzkaller.appspot.com/bug?extid=ff796f04613b4c84ad89 [1] Reported-by: syzbot syzbot+ff796f04613b4c84ad89@syzkaller.appspotmail.com Signed-off-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Fixes: 7746b32f467b3813 ("NFSD: add shrinker to reap courtesy clients on low memory condition") Reviewed-by: Jeff Layton jlayton@kernel.org Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfsd/nfsctl.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 6a29bcfc93909..dc74a947a440c 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1458,12 +1458,14 @@ static __net_init int nfsd_init_net(struct net *net) goto out_drc_error; retval = nfsd_reply_cache_init(nn); if (retval) - goto out_drc_error; + goto out_cache_error; get_random_bytes(&nn->siphash_key, sizeof(nn->siphash_key)); seqlock_init(&nn->writeverf_lock);
return 0;
+out_cache_error: + nfsd4_leases_net_shutdown(nn); out_drc_error: nfsd_idmap_shutdown(net); out_idmap_error: