CVE-2014-7970 VFS: DoS with USER_NS (rhbz 1151095 1151484)

This commit is contained in:
Josh Boyer 2014-10-10 11:19:12 -04:00
parent deaf6ef52a
commit 5c73e34a13
2 changed files with 53 additions and 0 deletions

View File

@ -753,6 +753,9 @@ Patch25109: revert-input-wacom-testing-result-shows-get_report-is-unnecessary.pa
Patch25110: 0001-ideapad-laptop-Blacklist-rfkill-control-on-the-Lenov.patch
Patch25111: 0002-ideapad-laptop-Change-Lenovo-Yoga-2-series-rfkill-ha.patch
#CVE-2014-7970 rhbz 1151095 1151484
Patch26032: mnt-Prevent-pivot_root-from-creating-a-loop-in-the-m.patch
# END OF PATCH DEFINITIONS
%endif
@ -1448,6 +1451,9 @@ ApplyPatch revert-input-wacom-testing-result-shows-get_report-is-unnecessary.pat
ApplyPatch 0001-ideapad-laptop-Blacklist-rfkill-control-on-the-Lenov.patch
ApplyPatch 0002-ideapad-laptop-Change-Lenovo-Yoga-2-series-rfkill-ha.patch
#CVE-2014-7970 rhbz 1151095 1151484
ApplyPatch mnt-Prevent-pivot_root-from-creating-a-loop-in-the-m.patch
# END OF PATCH APPLICATIONS
%endif
@ -2260,6 +2266,9 @@ fi
# and build.
%changelog
* Fri Oct 10 2014 Josh Boyer <jwboyer@fedoraproject.org>
- CVE-2014-7970 VFS: DoS with USER_NS (rhbz 1151095 1151484)
* Thu Oct 09 2014 Justin M. Forbes <jforbes@fedoraproject.org> - 3.14.21-100
- Linux v3.14.21

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@ -0,0 +1,44 @@
From: "Eric W. Biederman" <ebiederm@xmission.com>
Date: Wed, 8 Oct 2014 10:42:27 -0700
Subject: [PATCH] mnt: Prevent pivot_root from creating a loop in the mount
tree
Andy Lutomirski recently demonstrated that when chroot is used to set
the root path below the path for the new ``root'' passed to pivot_root
the pivot_root system call succeeds and leaks mounts.
In examining the code I see that starting with a new root that is
below the current root in the mount tree will result in a loop in the
mount tree after the mounts are detached and then reattached to one
another. Resulting in all kinds of ugliness including a leak of that
mounts involved in the leak of the mount loop.
Prevent this problem by ensuring that the new mount is reachable from
the current root of the mount tree.
Upstream-status: Submitted for 3.18
Bugzilla: 1151095,1151484
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
fs/namespace.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/namespace.c b/fs/namespace.c
index ef42d9bee212..74647c2fe69c 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2820,6 +2820,9 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
/* make sure we can reach put_old from new_root */
if (!is_path_reachable(old_mnt, old.dentry, &new))
goto out4;
+ /* make certain new is below the root */
+ if (!is_path_reachable(new_mnt, new.dentry, &root))
+ goto out4;
root_mp->m_count++; /* pin it so it won't go away */
lock_mount_hash();
detach_mnt(new_mnt, &parent_path);
--
1.9.3