| Date | Wed, 02 Nov 2011 15:15:11 -0700 | From | Greg KH <> | Subject | [105/107] Bluetooth: Prevent buffer overflow in l2cap config request |
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2.6.32-longterm review patch. If anyone has any objections, please let us know.
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From: Dan Rosenberg <drosenberg@vsecurity.com>
commit 7ac28817536797fd40e9646452183606f9e17f71 upstream.
A remote user can provide a small value for the command size field in the command header of an l2cap configuration request, resulting in an integer underflow when subtracting the size of the configuration request header. This results in copying a very large amount of data via memcpy() and destroying the kernel heap. Check for underflow.
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- net/bluetooth/l2cap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/bluetooth/l2cap.c +++ b/net/bluetooth/l2cap.c @@ -2720,7 +2720,7 @@ static inline int l2cap_config_req(struc /* Reject if config buffer is too small. */ len = cmd_len - sizeof(*req); - if (l2cap_pi(sk)->conf_len + len > sizeof(l2cap_pi(sk)->conf_req)) { + if (len < 0 || l2cap_pi(sk)->conf_len + len > sizeof(l2cap_pi(sk)->conf_req)) { l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, l2cap_build_conf_rsp(sk, rsp, L2CAP_CONF_REJECT, flags), rsp);
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