From: Chuck Lever chuck.lever@oracle.com
stable inclusion from stable-v4.19.325 commit d9a0d1f6e15859ea7a86a327f28491e23deaaa62 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBEAET CVE: CVE-2024-53217
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 1e02c641c3a43c88cecc08402000418e15578d38 ]
@ses is initialized to NULL. If __nfsd4_find_backchannel() finds no available backchannel session, setup_callback_client() will try to dereference @ses and segfault.
Fixes: dcbeaa68dbbd ("nfsd4: allow backchannel recovery") Reviewed-by: Jeff Layton jlayton@kernel.org Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Li Lingfeng lilingfeng3@huawei.com --- fs/nfsd/nfs4callback.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index b601e5915e6f..7ee25be394dc 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -1145,6 +1145,8 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb) ses = c->cn_session; } spin_unlock(&clp->cl_lock); + if (!c) + return;
err = setup_callback_client(clp, &conn, ses); if (err) {