Package: schroot
Version: 1.6.13-3+b2
Severity: important
Tags: patch
X-Debbugs-Cc: i...@ilbers.de, ub...@ilbers.de
Hello!
In case of multiple schroot processes checking for lock directory
presence at the same time more then one process can try to create this
directory. It happens because checking itself is not atomic:
(etc/setup.d/10mount, function do_umount_all)
```
if [ -e /var/lock/schroot ]; then
if [ ! -d /var/lock/schroot ]; then
error "/var/lock/schroot is not a directory"
exit 1
fi
else
mkdir -m 0700 /var/lock/schroot
fi
```
This will result in the following error:
| E: 10mount: mkdir: cannot create directory '/var/lock/schroot': File exists
To prevent second process fail on mkdir of already created lock
directory (and also allow creation of subfolders if not exist)
option -p can be added to mkdir command.
Pull request with the patch was sent to upstream repo:
https://codeberg.org/shelter/reschroot/pulls/12
-- System Information:
Debian Release: 12.8
APT prefers stable
APT policy: (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: arm64
Kernel: Linux 6.11.5+bpo-amd64 (SMP w/32 CPU threads; PREEMPT)
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: unable to detect
Versions of packages schroot depends on:
ii debconf [debconf-2.0] 1.5.82
ii libboost-filesystem1.74.0 1.74.0+ds1-21
ii libboost-iostreams1.74.0 1.74.0+ds1-21
ii libboost-program-options1.74.0 1.74.0+ds1-21
ii libc6 2.36-9+deb12u9
ii libgcc-s1 12.2.0-14
ii libpam0g 1.5.2-6+deb12u1
ii libstdc++6 12.2.0-14
ii libuuid1 2.38.1-5+deb12u2
ii schroot-common 1.6.13-3
ii sysvinit-utils [lsb-base] 3.06-4
schroot recommends no packages.
Versions of packages schroot suggests:
pn aufs-tools | unionfs-fuse <none>
pn btrfs-progs <none>
ii bzip2 1.0.8-5+b1
ii debootstrap 1.0.128+nmu2+deb12u1
pn lvm2 <none>
ii qemu-user-static 1:7.2+dfsg-7+deb12u7
ii xz-utils 5.4.1-0.2
pn zfsutils-linux <none>
ii zstd 1.5.4+dfsg2-5
-- debconf information:
schroot/bad-names:
>From 96e9404437efb826a0e81b36560b4430922616e6 Mon Sep 17 00:00:00 2001
From: Anton Mikanovich <ami...@ilbers.de>
Date: Mon, 2 Dec 2024 08:10:00 +0100
Subject: [PATCH] 10mount: Protect from races on do_umount_all
In case of multiple schroot processes checking for lock directory
presence at the same time more then one process can try to create this
directory. It happens because checking itself is not atomic.
This will result in the following error:
| E: 10mount: mkdir: cannot create directory '/var/lock/schroot': File exists
To prevent second process fail on mkdir of already created lock
directory (and also allow creation of subfolders if not exist) add -p
option to the command.
Signed-off-by: Anton Mikanovich <ami...@ilbers.de>
---
etc/setup.d/10mount | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/etc/setup.d/10mount b/etc/setup.d/10mount
index 5e734050..9fb8093a 100755
--- a/etc/setup.d/10mount
+++ b/etc/setup.d/10mount
@@ -83,7 +83,7 @@ do_umount_all()
exit 1
fi
else
- mkdir -m 0700 /var/lock/schroot
+ mkdir -m 0700 -p /var/lock/schroot
fi
if [ "$(stat -c "%u %g %a" /var/lock/schroot)" != "0 0 700" ]; then
--
2.39.5
