From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Jia-Ju Bai <baijiaju1990@gmail.com>,
Anna Schumaker <Anna.Schumaker@Netapp.com>,
Sasha Levin <sashal@kernel.org>,
linux-nfs@vger.kernel.org
Subject: [PATCH AUTOSEL 4.4 02/15] fs: nfs: Fix possible null-pointer dereferences in encode_attrs()
Date: Tue, 1 Oct 2019 12:45:20 -0400 [thread overview]
Message-ID: <20191001164533.16915-2-sashal@kernel.org> (raw)
In-Reply-To: <20191001164533.16915-1-sashal@kernel.org>
From: Jia-Ju Bai <baijiaju1990@gmail.com>
[ Upstream commit e2751463eaa6f9fec8fea80abbdc62dbc487b3c5 ]
In encode_attrs(), there is an if statement on line 1145 to check
whether label is NULL:
if (label && (attrmask[2] & FATTR4_WORD2_SECURITY_LABEL))
When label is NULL, it is used on lines 1178-1181:
*p++ = cpu_to_be32(label->lfs);
*p++ = cpu_to_be32(label->pi);
*p++ = cpu_to_be32(label->len);
p = xdr_encode_opaque_fixed(p, label->label, label->len);
To fix these bugs, label is checked before being used.
These bugs are found by a static analysis tool STCheck written by us.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/nfs4xdr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 1cb50bb898b01..15cd9db6d616d 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1123,7 +1123,7 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap,
} else
*p++ = cpu_to_be32(NFS4_SET_TO_SERVER_TIME);
}
- if (bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
+ if (label && (bmval[2] & FATTR4_WORD2_SECURITY_LABEL)) {
*p++ = cpu_to_be32(label->lfs);
*p++ = cpu_to_be32(label->pi);
*p++ = cpu_to_be32(label->len);
--
2.20.1
parent reply other threads:[~2019-10-01 16:46 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <20191001164533.16915-1-sashal@kernel.org>]
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