54 lines
1.7 KiB
Diff
54 lines
1.7 KiB
Diff
From 9eb8532ccacf1cfdb7ba18f51eba68776852ef7c Mon Sep 17 00:00:00 2001
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From: Vincent Mihalkovic <vmihalko@redhat.com>
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Date: Thu, 8 Feb 2024 22:10:58 +0100
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Subject: [PATCH] Re-fix use of strdup on a NULL pointer (re: 9a9da2c2) (#718)
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Thank you @lzaoral for debugging this issue and creating this
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reproducer:
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$ tty # check that the shell is connected to a pseudoterminal
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/dev/pts/4
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$ mkdir /var/tmp/chroottest
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$ dnf --releasever=39 --installroot=/var/tmp/chroottest install ksh
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$ echo "/dev/udp/127.0.0.1/514;0;104" |
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sudo tee /var/tmp/chroottest/etc/ksh_audit
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$ sudo chroot /var/tmp/chroottest /bin/ksh -lic 'exit 0'
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(ksh segfaults)
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Analysis: On Linux, ttyname(3)[*] may fail if:
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* EBADF Bad file descriptor.
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* ENODEV fd refers to a slave pseudoterminal device but the
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corresponding pathname could not be found [...].
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* ENOTTY fd does not refer to a terminal device.
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Calling isatty(3) before ttyname(3) only prevents the first and
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third cases.
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src/cmd/ksh93/edit/history.c: sh_histinit():
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- To catch the second case, let's call ttyname(2) directly, check
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for NULL and remove the redundant isatty() call.
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[*] https://man7.org/linux/man-pages/man3/ttyname.3.html
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---
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src/cmd/ksh93/edit/history.c | 3 ++-
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1 file changed, 2 insertions(+), 1 deletion(-)
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diff --git a/src/cmd/ksh93/edit/history.c b/src/cmd/ksh93/edit/history.c
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index de5e4a8..222d4bc 100644
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--- a/src/cmd/ksh93/edit/history.c
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+++ b/src/cmd/ksh93/edit/history.c
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@@ -395,7 +395,8 @@ retry:
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if(fd>=0)
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{
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fcntl(fd,F_SETFD,FD_CLOEXEC);
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- hp->tty = strdup(ttyname(2));
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+ const char* tty = ttyname(2);
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+ hp->tty = strdup(tty?tty:"notty");
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hp->auditfp = sfnew((Sfio_t*)0,NULL,-1,fd,SF_WRITE);
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}
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}
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--
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2.43.0
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