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Commit 80aa4e10 authored by Dan Carpenter's avatar Dan Carpenter Committed by David S. Miller
Browse files

x25: add a sanity check parsing X.25 facilities 



This was found with a manual audit and I don't have a reproducer.  We
limit ->calling_len and ->called_len when we get them from
copy_from_user() in x25_ioctl() so when they come from skb->data then
we should cap them there as well.

Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cab6ce9e

net/x25/x25_facilities.c

+4 −0
Original line number Diff line number Diff line
@@ -156,6 +156,8 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities, 
			case X25_FAC_CALLING_AE:

				if (p[1] > X25_MAX_DTE_FACIL_LEN || p[1] <= 1)

					return -1;

				if (p[2] > X25_MAX_AE_LEN)

					return -1;

				dte_facs->calling_len = p[2];

				memcpy(dte_facs->calling_ae, &p[3], p[1] - 1);

				*vc_fac_mask |= X25_MASK_CALLING_AE;
@@ -163,6 +165,8 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities, 
			case X25_FAC_CALLED_AE:

				if (p[1] > X25_MAX_DTE_FACIL_LEN || p[1] <= 1)

					return -1;

				if (p[2] > X25_MAX_AE_LEN)

					return -1;

				dte_facs->called_len = p[2];

				memcpy(dte_facs->called_ae, &p[3], p[1] - 1);

				*vc_fac_mask |= X25_MASK_CALLED_AE;