ppp, slip: Validate VJ compression slot parameters completely
authorBen Hutchings <ben@decadent.org.uk>
Sun, 1 Nov 2015 16:22:53 +0000 (16:22 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 29 Jan 2016 05:49:35 +0000 (21:49 -0800)
commitf82699de104eaf8a7ffc2849a566a94818dd8a3c
treeb4f323ad2f9bc6f8a95124df9fd1e1c8d6d91004
parent069872265c33b108afcc613b489cb3070437c249
ppp, slip: Validate VJ compression slot parameters completely

[ Upstream commit 4ab42d78e37a294ac7bc56901d563c642e03c4ae ]

Currently slhc_init() treats out-of-range values of rslots and tslots
as equivalent to 0, except that if tslots is too large it will
dereference a null pointer (CVE-2015-7799).

Add a range-check at the top of the function and make it return an
ERR_PTR() on error instead of NULL.  Change the callers accordingly.

Compile-tested only.

Reported-by: 郭永刚 <guoyonggang@360.cn>
References: http://article.gmane.org/gmane.comp.security.oss.general/17908
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/isdn/i4l/isdn_ppp.c
drivers/net/ppp/ppp_generic.c
drivers/net/slip/slhc.c
drivers/net/slip/slip.c