[PATCH 4.0 35/55] selinux: fix setting of security labels on NFS

From: Greg Kroah-Hartman
Date: Wed Jul 08 2015 - 04:08:16 EST


4.0-stable review patch. If anyone has any objections, please let me know.

------------------

From: "J. Bruce Fields" <bfields@xxxxxxxxxx>

commit 9fc2b4b436cff7d8403034676014f1be9d534942 upstream.

Before calling into the filesystem, vfs_setxattr calls
security_inode_setxattr, which ends up calling selinux_inode_setxattr in
our case. That returns -EOPNOTSUPP whenever SBLABEL_MNT is not set.
SBLABEL_MNT was supposed to be set by sb_finish_set_opts, which sets it
only if selinux_is_sblabel_mnt returns true.

The selinux_is_sblabel_mnt logic was broken by eadcabc697e9 "SELinux: do
all flags twiddling in one place", which didn't take into the account
the SECURITY_FS_USE_NATIVE behavior that had been introduced for nfs
with eb9ae686507b "SELinux: Add new labeling type native labels".

This caused setxattr's of security labels over NFSv4.2 to fail.

Cc: Eric Paris <eparis@xxxxxxxxxx>
Cc: David Quigley <dpquigl@xxxxxxxxxxxxxxx>
Reported-by: Richard Chan <rc556677@xxxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Acked-by: Stephen Smalley <sds@xxxxxxxxxxxxx>
[PM: added the stable dependency]
Signed-off-by: Paul Moore <pmoore@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
security/selinux/hooks.c | 1 +
1 file changed, 1 insertion(+)

--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -404,6 +404,7 @@ static int selinux_is_sblabel_mnt(struct
return sbsec->behavior == SECURITY_FS_USE_XATTR ||
sbsec->behavior == SECURITY_FS_USE_TRANS ||
sbsec->behavior == SECURITY_FS_USE_TASK ||
+ sbsec->behavior == SECURITY_FS_USE_NATIVE ||
/* Special handling. Genfs but also in-core setxattr handler */
!strcmp(sb->s_type->name, "sysfs") ||
!strcmp(sb->s_type->name, "pstore") ||


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