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| author | Amir Goldstein <amir73il@gmail.com> | 2020-12-19 13:05:27 +0300 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2021-01-05 04:41:09 +0300 |
| commit | a9ffe682c58aaff643764547f5420e978b6e0830 (patch) | |
| tree | 9726400d6558859dd38e83caec80cceba6a4885a /security | |
| parent | 95ca90726ea6c9444c752ea370e35ec7b6776434 (diff) | |
| download | linux-a9ffe682c58aaff643764547f5420e978b6e0830.tar.xz | |
selinux: fix inconsistency between inode_getxattr and inode_listsecurity
When inode has no listxattr op of its own (e.g. squashfs) vfs_listxattr
calls the LSM inode_listsecurity hooks to list the xattrs that LSMs will
intercept in inode_getxattr hooks.
When selinux LSM is installed but not initialized, it will list the
security.selinux xattr in inode_listsecurity, but will not intercept it
in inode_getxattr. This results in -ENODATA for a getxattr call for an
xattr returned by listxattr.
This situation was manifested as overlayfs failure to copy up lower
files from squashfs when selinux is built-in but not initialized,
because ovl_copy_xattr() iterates the lower inode xattrs by
vfs_listxattr() and vfs_getxattr().
Match the logic of inode_listsecurity to that of inode_getxattr and
do not list the security.selinux xattr if selinux is not initialized.
Reported-by: Michael Labriola <michael.d.labriola@gmail.com>
Tested-by: Michael Labriola <michael.d.labriola@gmail.com>
Link: https://lore.kernel.org/linux-unionfs/2nv9d47zt7.fsf@aldarion.sourceruckus.org/
Fixes: c8e222616c7e ("selinux: allow reading labels before policy is loaded")
Cc: stable@vger.kernel.org#v5.9+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Diffstat (limited to 'security')
| -rw-r--r-- | security/selinux/hooks.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 75e7568cf607..7fb7ff03eaa9 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3414,6 +3414,10 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name, static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) { const int len = sizeof(XATTR_NAME_SELINUX); + + if (!selinux_initialized(&selinux_state)) + return 0; + if (buffer && len <= buffer_size) memcpy(buffer, XATTR_NAME_SELINUX, len); return len; |