| Andrew Geissler | 220dafd | 2023-10-04 10:18:08 -0500 | [diff] [blame] | 1 | From 4133a888aa256312186962ab70d4a36eed5920c1 Mon Sep 17 00:00:00 2001 |
| 2 | From: Brooks Davis <brooks@FreeBSD.org> |
| 3 | Date: Mon, 26 Sep 2022 18:56:51 +0100 |
| 4 | Subject: [PATCH] telnetd: fix two-byte input crash |
| 5 | |
| 6 | Move initialization of the slc table earlier so it doesn't get |
| 7 | accessed before that happens. |
| 8 | |
| 9 | For details on the issue, see: |
| 10 | https://pierrekim.github.io/blog/2022-08-24-2-byte-dos-freebsd-netbsd-telnetd-netkit-telnetd-inetutils-telnetd-kerberos-telnetd.html |
| 11 | |
| 12 | Reviewed by: cy |
| 13 | Obtained from: NetBSD via cy |
| 14 | Differential Revision: https://reviews.freebsd.org/D36680 |
| 15 | |
| 16 | CVE: CVE-2022-39028 |
| 17 | Upstream-Status: Backport [https://cgit.freebsd.org/src/commit/?id=6914ffef4e23] |
| 18 | |
| 19 | (cherry picked from commit 6914ffef4e2318ca1d0ead28eafb6f06055ce0f8) |
| 20 | Signed-off-by: Sanjay Chitroda <sanjay.chitroda@einfochips.com> |
| 21 | |
| 22 | --- |
| 23 | telnetd/telnetd.c | 10 +++++----- |
| 24 | 1 file changed, 5 insertions(+), 5 deletions(-) |
| 25 | |
| 26 | diff --git a/telnetd/telnetd.c b/telnetd/telnetd.c |
| 27 | index f36f505..efa0fe1 100644 |
| 28 | --- a/telnetd/telnetd.c |
| 29 | +++ b/telnetd/telnetd.c |
| 30 | @@ -615,6 +615,11 @@ doit(struct sockaddr_in *who) |
| 31 | int level; |
| 32 | char user_name[256]; |
| 33 | |
| 34 | + /* |
| 35 | + * Initialize the slc mapping table. |
| 36 | + */ |
| 37 | + get_slc_defaults(); |
| 38 | + |
| 39 | /* |
| 40 | * Find an available pty to use. |
| 41 | */ |
| 42 | @@ -698,11 +703,6 @@ void telnet(int f, int p) |
| 43 | char *HE; |
| 44 | const char *IM; |
| 45 | |
| 46 | - /* |
| 47 | - * Initialize the slc mapping table. |
| 48 | - */ |
| 49 | - get_slc_defaults(); |
| 50 | - |
| 51 | /* |
| 52 | * Do some tests where it is desireable to wait for a response. |
| 53 | * Rather than doing them slowly, one at a time, do them all |