Blame SOURCES/CVE-2023-0386.patch

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From 49fc47e81624d594ff10837b9cd34f14c9e26046 Mon Sep 17 00:00:00 2001
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From: Ryan Sullivan <rysulliv@redhat.com>
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Date: Wed, 15 Mar 2023 09:20:36 -0400
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Subject: [KPATCH CVE-2023-0386] kpatch fixes for CVE-2023-0386
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Kernels:
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4.18.0-425.3.1.el8
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4.18.0-425.10.1.el8_7
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4.18.0-425.13.1.el8_7
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Kpatch-MR: https://gitlab.com/redhat/prdsc/rhel/src/kpatch/rhel-8/-/merge_requests/92
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Approved-by: Joe Lawrence (@joe.lawrence)
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Approved-by: Yannick Cote (@ycote1)
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Changes since last build:
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[x86_64]:
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copy_up.o: changed function: ovl_copy_up_one
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copy_up.o: new function: ovl_do_copy_up
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[ppc64le]:
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copy_up.o: changed function: ovl_copy_up_one
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---------------------------
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Modifications: none
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commit a9ae1a96322125120bbb5177b1c76586f886a8db
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Author: Miklos Szeredi <mszeredi@redhat.com>
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Date:   Tue Jan 24 16:41:18 2023 +0100
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    ovl: fail on invalid uid/gid mapping at copy up
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    Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2165341
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    CVE: CVE-2023-0386
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    If st_uid/st_gid doesn't have a mapping in the mounter's user_ns, then
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    copy-up should fail, just like it would fail if the mounter task was doing
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    the copy using "cp -a".
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    There's a corner case where the "cp -a" would succeed but copy up fail: if
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    there's a mapping of the invalid uid/gid (65534 by default) in the user
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    namespace.  This is because stat(2) will return this value if the mapping
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    doesn't exist in the current user_ns and "cp -a" will in turn be able to
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    create a file with this uid/gid.
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    This behavior would be inconsistent with POSIX ACL's, which return -1 for
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    invalid uid/gid which result in a failed copy.
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    For consistency and simplicity fail the copy of the st_uid/st_gid are
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    invalid.
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    Fixes: 459c7c565ac3 ("ovl: unprivieged mounts")
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    Cc: <stable@vger.kernel.org> # v5.11
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    Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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    Reviewed-by: Christian Brauner <brauner@kernel.org>
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    Reviewed-by: Seth Forshee <sforshee@kernel.org>
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    (cherry picked from commit 4f11ada10d0ad3fd53e2bd67806351de63a4f9c3)
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    Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Signed-off-by: Ryan Sullivan <rysulliv@redhat.com>
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---
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 fs/overlayfs/copy_up.c | 4 ++++
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 1 file changed, 4 insertions(+)
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diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
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index edd818b77aac..7c51ca835fc7 100644
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--- a/fs/overlayfs/copy_up.c
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+++ b/fs/overlayfs/copy_up.c
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@@ -889,6 +889,10 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
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 	if (err)
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 		return err;
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+	if (!kuid_has_mapping(current_user_ns(), ctx.stat.uid) ||
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+	    !kgid_has_mapping(current_user_ns(), ctx.stat.gid))
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+		return -EOVERFLOW;
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+
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 	ctx.metacopy = ovl_need_meta_copy_up(dentry, ctx.stat.mode, flags);
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 	if (parent) {
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-- 
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2.39.2
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