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| author | Vivek Goyal <vgoyal@redhat.com> | 2021-02-11 21:03:03 +0300 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2021-03-09 03:34:38 +0300 |
| commit | 7fa2e79a6bb924fa4b2de5766dab31f0f47b5ab6 (patch) | |
| tree | 7646b2b0ede6c9943b5e90c591951715b9d92040 /security | |
| parent | a38fd8748464831584a19438cbb3082b5a2dab15 (diff) | |
| download | linux-7fa2e79a6bb924fa4b2de5766dab31f0f47b5ab6.tar.xz | |
selinux: Allow context mounts for unpriviliged overlayfs
Now overlayfs allow unpriviliged mounts. That is root inside a non-init
user namespace can mount overlayfs. This is being added in 5.11 kernel.
Giuseppe tried to mount overlayfs with option "context" and it failed
with error -EACCESS.
$ su test
$ unshare -rm
$ mkdir -p lower upper work merged
$ mount -t overlay -o lowerdir=lower,workdir=work,upperdir=upper,userxattr,context='system_u:object_r:container_file_t:s0' none merged
This fails with -EACCESS. It works if option "-o context" is not specified.
Little debugging showed that selinux_set_mnt_opts() returns -EACCESS.
So this patch adds "overlay" to the list, where it is fine to specific
context from non init_user_ns.
Reported-by: Giuseppe Scrivano <gscrivan@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
[PM: trimmed the changelog from the description]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Diffstat (limited to 'security')
| -rw-r--r-- | security/selinux/hooks.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index ddd097790d47..eca9fc0ba764 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -760,7 +760,8 @@ static int selinux_set_mnt_opts(struct super_block *sb, if (sb->s_user_ns != &init_user_ns && strcmp(sb->s_type->name, "tmpfs") && strcmp(sb->s_type->name, "ramfs") && - strcmp(sb->s_type->name, "devpts")) { + strcmp(sb->s_type->name, "devpts") && + strcmp(sb->s_type->name, "overlay")) { if (context_sid || fscontext_sid || rootcontext_sid || defcontext_sid) { rc = -EACCES; |