fix by ignoring EINVAL on remount of proc

cherry-pick from: 0b7633309620df26f57673682eca33806b3826e7
This commit is contained in:
shangyibin 2022-02-19 18:02:46 +08:00 committed by z30031144
parent 7ec1c7315a
commit 222cd35a97
2 changed files with 59 additions and 14 deletions

View File

@ -0,0 +1,40 @@
From 1961dccea09176a401bc8fc5e1769ab426308314 Mon Sep 17 00:00:00 2001
From: benaryorg <binary@benary.org>
Date: Fri, 4 Jun 2021 12:34:52 +0000
Subject: [PATCH] fix #648 by ignoring EINVAL on-remount of proc
When using --mount-proc=/some/path then unshare fails if the path provided is not already mounted due to the mount(2) call to change the propagation of the mount.
In such a case mount(2) returns EINVAL, which however is used for a variety of other errors.
If this error is ignored mistakenly the effects however should be neglible since:
1. the mount of proc afterwards happens regardless, errors of which are not ignored
2. the propagation change of root uses MS_REC, which shold already change the propagation of all mounts recursively
Furthermore /proc is not touched if --mount-proc specifies a different mount point.
This should not cause too much unexpected behaviour due to point 2 from above in any case.
Specifying --mount-proc with a different path also means that unshare(3) is not instructed to touch /proc, thus /proc not being touched should not be unexpected.
As a side note, if unshare is called with /proc as an (implicit) parameter to --mount-proc then /proc is a stacked mount, meaning if /proc is unmounted it in the namespace the host /proc is visible again, thus not touching /proc with a different parameter does not constitute more information leakage than the alternative, quite contary it may even be the desired behaviour.
Signed-off-by: benaryorg <binary@benary.org>
---
sys-utils/unshare.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/sys-utils/unshare.c b/sys-utils/unshare.c
index e5627d3c64..820691ba35 100644
--- a/sys-utils/unshare.c
+++ b/sys-utils/unshare.c
@@ -650,8 +650,11 @@ int main(int argc, char *argv[])
err(EXIT_FAILURE, _("cannot chdir to '%s'"), newdir);
if (procmnt) {
- if (!newroot && mount("none", procmnt, NULL, MS_PRIVATE|MS_REC, NULL) != 0)
- err(EXIT_FAILURE, _("cannot change %s filesystem propagation"), procmnt);
+ if (!newroot && mount("none", procmnt, NULL, MS_PRIVATE|MS_REC, NULL))
+ /* custom procmnt means that proc is very likely not mounted, causing EINVAL
+ ignoring the error in this specific instance is safe */
+ if(errno != EINVAL)
+ err(EXIT_FAILURE, _("cannot change %s filesystem propagation"), procmnt);
if (mount("proc", procmnt, "proc", MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL) != 0)
err(EXIT_FAILURE, _("mount %s failed"), procmnt);
}

View File

@ -3,7 +3,7 @@
Name: util-linux
Version: 2.37.2
Release: 4
Release: 6
Summary: A random collection of Linux utilities
License: GPLv2 and GPLv2+ and LGPLv2+ and BSD with advertising and Public Domain
URL: https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git
@ -24,17 +24,17 @@ Patch6002: backport-CVE-2021-3996.patch
Patch6003: realloc-buffer-when-header-size-changed.patch
Patch6004: fix-size-use-for-stdin.patch
Patch6005: segmentation-fault-on-invalid-unicode-input-passed-to-s-option.patch
Patch6006: backport-su-bash-completion-offer-usernames-rather-than-files.patch
Patch6007: backport-Fix-memory-leaks-in-the-chcpu.patch
Patch6008: backport-logger-fix-prio-prefix-doesn-t-use-priority-default.patch
Patch6009: backport-vipw-flush-stdout-before-getting-answer.patch
Patch6010: backport-login-Restore-tty-size-after-calling-vhangup.patch
Patch6011: backport-Forward-value-of-sector_size-instead-of-its-address.patch
Patch6012: backport-libfdisk-dereference-of-possibly-NULL-gcc-analyzer.patch
Patch6013: backport-libfdisk-check-calloc-return-gcc-analyzer.patch
Patch6014: backport-mcookie-fix-infinite-loop-when-use-f.patch
Patch6015: backport-sfdisk-write-empty-label-also-when-only-ignored-part.patch
Patch6006: backport-fix-by-ignoring-EINVAL-on-remount-of-proc.patch
Patch6007: backport-su-bash-completion-offer-usernames-rather-than-files.patch
Patch6008: backport-Fix-memory-leaks-in-the-chcpu.patch
Patch6009: backport-logger-fix-prio-prefix-doesn-t-use-priority-default.patch
Patch6010: backport-vipw-flush-stdout-before-getting-answer.patch
Patch6011: backport-login-Restore-tty-size-after-calling-vhangup.patch
Patch6012: backport-Forward-value-of-sector_size-instead-of-its-address.patch
Patch6013: backport-libfdisk-dereference-of-possibly-NULL-gcc-analyzer.patch
Patch6014: backport-libfdisk-check-calloc-return-gcc-analyzer.patch
Patch6015: backport-mcookie-fix-infinite-loop-when-use-f.patch
Patch6016: backport-sfdisk-write-empty-label-also-when-only-ignored-part.patch
Patch9000: Add-check-to-resolve-uname26-version-test-failed.patch
Patch9001: SKIPPED-no-root-permissions-test.patch
@ -56,7 +56,6 @@ Provides: /bin/dmesg /bin/kill /bin/more /bin/mount /bin/umount /sbin/blki
Provides: /sbin/blockdev /sbin/findfs /sbin/fsck /sbin/nologin
Obsoletes: eject <= 2.1.5 rfkill <= 0.5 util-linux-ng < 2.19 hardlink <= 1:1.3-9
%description
The util-linux package contains a random collection of files that
implements some low-level basic linux utilities.
@ -405,12 +404,18 @@ fi
%{_mandir}/man8/{swapoff.8*,swapon.8*,switch_root.8*,umount.8*,wdctl.8.gz,wipefs.8*,zramctl.8*}
%changelog
* Thu Jun 30 2022 shangyibin<shangyibin1@h-partners.com> - 2.37.2-4
* Thu Jun 30 2022 shangyibin<shangyibin1@h-partners.com> - 2.37.2-6
- Type:bugfix
- ID:NA
- SUG:NA
- DESC:Sync community patches
* Sat Feb 19 2022 shangyibin<shangyibin1@h-partners.com> - 2.37.2-5
- Type:bugfix
- ID:NA
- SUG:NA
- DESC:fix by ignoring EINVAL on remount of proc
* Fri Feb 18 2022 shangyibin<shangyibin1@h-partners.com> - 2.37.2-4
- Type:bugfix
- ID:NA