From f58a08152ce4198a2a1da162b97ecf8264c24866 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Thu, 26 Jan 2012 19:13:25 +0200 Subject: lib/digsig: additional sanity checks against badly formated key payload Added sanity checks for possible wrongly formatted key payload data: - minimum key payload size - zero modulus length - corrected upper key payload boundary. Signed-off-by: Dmitry Kasatkin Reviewed-by: Tetsuo Handa Signed-off-by: James Morris --- lib/digsig.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/digsig.c b/lib/digsig.c index fd2402f67f8..5d840ac64fb 100644 --- a/lib/digsig.c +++ b/lib/digsig.c @@ -105,6 +105,10 @@ static int digsig_verify_rsa(struct key *key, down_read(&key->sem); ukp = key->payload.data; + + if (ukp->datalen < sizeof(*pkh)) + goto err1; + pkh = (struct pubkey_hdr *)ukp->data; if (pkh->version != 1) @@ -117,7 +121,7 @@ static int digsig_verify_rsa(struct key *key, goto err1; datap = pkh->mpi; - endp = datap + ukp->datalen; + endp = ukp->data + ukp->datalen; for (i = 0; i < pkh->nmpi; i++) { unsigned int remaining = endp - datap; @@ -128,7 +132,8 @@ static int digsig_verify_rsa(struct key *key, mblen = mpi_get_nbits(pkey[0]); mlen = (mblen + 7)/8; - err = -ENOMEM; + if (mlen == 0) + goto err; out1 = kzalloc(mlen, GFP_KERNEL); if (!out1) -- cgit v1.2.3-18-g5258