ksh/ksh-20120801-segfault-strdup.patch
Lukáš Zaoral 505cee0471
Fix segfault in strdup
Resolves: RHEL-11982
2023-11-01 13:19:55 +01:00

46 lines
1.7 KiB
Diff

From 9a9da2c299a0adcd36b4efd1b1c0ee2883beba7b Mon Sep 17 00:00:00 2001
From: Johnothan King <johnothanking@protonmail.com>
Date: Mon, 6 Jul 2020 13:51:44 -0700
Subject: [PATCH] Fix use of strdup on a NULL pointer (#63)
The following set of commands can rarely cause a memory fault
when auditing[*] is enabled, although most of the time it will
simply cause ksh to write '(null)' to the auditing file in place
of a tty name:
$ [ -e /etc/ksh_audit ] || echo "/tmp/ksh_auditfile;$(id -u)" | sudo tee /etc/ksh_audit;
$ v=$(ksh 2> /dev/null +o rc -ic $'getopts a:bc: opt --man\nprint $?')
$ cat /tmp/ksh_auditfile
1000;1593599493;(null); getopts a:bc: opt --man
This happens because strdup is used unconditionally on the pointer
returned by 'ttyname', which can be NULL if stderr is closed. This
then causes 'hp->tty' to be set to null, as strdup returns NULL.
See https://github.com/att/ast/issues/1028
src/cmd/ksh93/edit/history.c:
- Make strdup duplicate 'notty' instead of NULL to prevent
crashes.
[*] https://blog.fpmurphy.com/2008/12/ksh93-auditing-and-accounting.html
Cherry-picked-by: Lukáš Zaoral <lzaoral@redhat.com>
Upstream-commit: 9a9da2c299a0adcd36b4efd1b1c0ee2883beba7b
---
src/cmd/ksh93/edit/history.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/src/cmd/ksh93/edit/history.c b/src/cmd/ksh93/edit/history.c
index d6737e209ca0..f40f27b4a4d7 100644
--- a/src/cmd/ksh93/edit/history.c
+++ b/src/cmd/ksh93/edit/history.c
@@ -395,7 +395,7 @@ int sh_histinit(void *sh_context)
if(fd>=0)
{
fcntl(fd,F_SETFD,FD_CLOEXEC);
- hp->tty = strdup(ttyname(2));
+ hp->tty = strdup(isatty(2)?ttyname(2):"notty");
hp->auditfp = sfnew((Sfio_t*)0,NULL,-1,fd,SF_WRITE);
}
}