From bdbf7a05e26f3c5fd437c99e2755ffde186ddc80 Mon Sep 17 00:00:00 2001 From: Andrea zi0Black Cappa Date: Wed, 18 May 2022 16:30:08 +0000 Subject: [PATCH] net: nfs: Fix CVE-2022-30767 (old CVE-2019-14196) This patch mitigates the vulnerability identified via CVE-2019-14196. The previous patch was bypassed/ineffective, and now the vulnerability is identified via CVE-2022-30767. The patch removes the sanity check introduced to mitigate CVE-2019-14196 since it's ineffective. filefh3_length is changed to unsigned type integer, preventing negative numbers from being used during comparison with positive values during size sanity checks. Signed-off-by: Andrea zi0Black Cappa --- net/nfs.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/net/nfs.c b/net/nfs.c index 3c01cebd96..9152ab742e 100644 --- a/net/nfs.c +++ b/net/nfs.c @@ -52,7 +52,7 @@ static const ulong nfs_timeout = CONFIG_NFS_TIMEOUT; static char dirfh[NFS_FHSIZE]; /* NFSv2 / NFSv3 file handle of directory */ static char filefh[NFS3_FHSIZE]; /* NFSv2 / NFSv3 file handle */ -static int filefh3_length; /* (variable) length of filefh when NFSv3 */ +static unsigned int filefh3_length; /* (variable) length of filefh when NFSv3 */ static enum net_loop_state nfs_download_state; static struct in_addr nfs_server_ip; @@ -573,8 +573,6 @@ static int nfs_lookup_reply(uchar *pkt, unsigned len) filefh3_length = ntohl(rpc_pkt.u.reply.data[1]); if (filefh3_length > NFS3_FHSIZE) filefh3_length = NFS3_FHSIZE; - if (((uchar *)&(rpc_pkt.u.reply.data[0]) - (uchar *)(&rpc_pkt) + filefh3_length) > len) - return -NFS_RPC_DROP; memcpy(filefh, rpc_pkt.u.reply.data + 2, filefh3_length); } -- 2.39.5