6.12-stable review patch. If anyone has any objections, please let me know.
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From: Shardul Bankar shardul.b@mpiricsoftware.com
[ Upstream commit df8d829bba3adcf3cc744c01d933b6fd7cf06e91 ]
When nfsd_create_serv() calls percpu_ref_init() to initialize nn->nfsd_net_ref, it allocates both a percpu reference counter and a percpu_ref_data structure (64 bytes). However, if the function fails later due to svc_create_pooled() returning NULL or svc_bind() returning an error, these allocations are not cleaned up, resulting in a memory leak.
The leak manifests as: - Unreferenced percpu allocation (8 bytes per CPU) - Unreferenced percpu_ref_data structure (64 bytes)
Fix this by adding percpu_ref_exit() calls in both error paths to properly clean up the percpu_ref_init() allocations.
This patch fixes the percpu_ref leak in nfsd_create_serv() seen as an auxiliary leak in syzbot report 099461f8558eb0a1f4f3; the prepare_creds() and vsock-related leaks in the same report remain to be addressed separately.
Reported-by: syzbot+099461f8558eb0a1f4f3@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=099461f8558eb0a1f4f3 Fixes: 47e988147f40 ("nfsd: add nfsd_serv_try_get and nfsd_serv_put") Signed-off-by: Shardul Bankar shardul.b@mpiricsoftware.com 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/nfssvc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 571a6ae90833..cc185c00e309 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -667,13 +667,16 @@ int nfsd_create_serv(struct net *net) serv = svc_create_pooled(nfsd_programs, ARRAY_SIZE(nfsd_programs), &nn->nfsd_svcstats, nfsd_max_blksize, nfsd); - if (serv == NULL) + if (serv == NULL) { + percpu_ref_exit(&nn->nfsd_net_ref); return -ENOMEM; + }
serv->sv_maxconn = nn->max_connections; error = svc_bind(serv, net); if (error < 0) { svc_destroy(&serv); + percpu_ref_exit(&nn->nfsd_net_ref); return error; } spin_lock(&nfsd_notifier_lock);