[Bug 1422795] Re: bash crashes often if inputrc contains revert-all-at-newline
Mathew Hodson
mathew.hodson at gmail.com
Tue Nov 3 20:19:54 UTC 2015
** Changed in: bash (Ubuntu)
Importance: Undecided => High
** Changed in: bash (Ubuntu)
Status: Confirmed => Fix Released
** Project changed: gnubash => ubuntu-translations
** No longer affects: ubuntu-translations
--
You received this bug notification because you are a member of Ubuntu
Sponsors Team, which is subscribed to the bug report.
https://bugs.launchpad.net/bugs/1422795
Title:
bash crashes often if inputrc contains revert-all-at-newline
Status in bash package in Ubuntu:
Fix Released
Status in bash package in Debian:
Fix Released
Bug description:
Debian bug: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=747341
The Debian bug includes complete reproduction case. Basically:
with .inputrc containing
set revert-all-at-newline On
Go back in the commandline history, edit a command, then submit a different command (may be empty)
Such as:
$ ls something
$ <UP><CTRL+W><DOWN><ENTER>
Attached diff is confirmed to fix the issue.
ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: bash 4.3-7ubuntu1.5 [origin: goobuntu-trusty-testing-desktop]
ProcVersionSignature: Ubuntu 3.13.0-44.73-generic 3.13.11-ckt12
Uname: Linux 3.13.0-44-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.14.1-0ubuntu3.6
Architecture: amd64
CurrentDesktop: X-Cinnamon
Date: Tue Feb 17 15:49:30 2015
SourcePackage: bash
UpgradeStatus: No upgrade log present (probably fresh install)
modified.conffile..etc.bash.bashrc: [modified]
mtime.conffile..etc.bash.bashrc: 2015-01-27T03:27:18.751405
[Test Case]
Adapted from the Debian bug report:
1. echo "set revert-all-at-newline on" > bug.inputrc
2. INPUTRC=bug.inputrc bash
3. echo hello
4. ^P^U^N^M [Hold down control and type "punm".]
Bash should die immediately with SIGABRT.
[Regression Potential]
Relatively low.
The change has no effect at all unless _rl_revert_all_lines() is called,
which only happens if revert-all-at-newline is set, and then only when a
newline is typed. So, the potential for regression is essentially zero for
non-interactive shells and for anyone not using revert-all-at-newline (which
is not the default).
Further, this change appeared upstream and in both Debian and Ubuntu over
a year ago, so it's had plenty of public testing.
lib/readline/misc.c:_rl_revert_all_lines() contains a loop which iterates
over history entries, reverting changes to each history entry. This patch
causes entry->data, which points to the per-entry undo list, to be cleared
before reverting edits rather than after. At first glance, this shouldn't
make any difference. However, it prevents rl_do_undo() from replacing the
history entry with one reflecting the change. Otherwise, the entry gets
freed, leaving _rl_revert_all_lines() with an invalid pointer.
_Not_ having an invalid pointer and double-free certainly can't be worse
than the current situation. Since we're avoiding is making the pointer
invalid rather than not doing the free, the chance of a new leak is pretty
much nonexistent.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/bash/+bug/1422795/+subscriptions
More information about the Ubuntu-sponsors
mailing list