3.16.60-rc1 review patch. If anyone has any objections, please let me know.
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From: Marc Dionne marc.dionne@auristor.com
commit fd2498211a551fd42b2d6b9050d649d43536e75c upstream.
The AFS_ACE_READ and AFS_ACE_WRITE permission bits should not be used to make access decisions for the directory itself. They are meant to control access for the objects contained in that directory.
Reading a directory is allowed if the AFS_ACE_LOOKUP bit is set. This would cause an incorrect access denied error for a directory with AFS_ACE_LOOKUP but not AFS_ACE_READ.
The AFS_ACE_WRITE bit does not allow operations that modify the directory. For a directory with AFS_ACE_WRITE but neither AFS_ACE_INSERT nor AFS_ACE_DELETE, this would result in trying operations that would ultimately be denied by the server.
Signed-off-by: Marc Dionne marc.dionne@auristor.com Signed-off-by: David Howells dhowells@redhat.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Ben Hutchings ben@decadent.org.uk --- fs/afs/security.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
--- a/fs/afs/security.c +++ b/fs/afs/security.c @@ -327,12 +327,11 @@ int afs_permission(struct inode *inode, if (!(access & AFS_ACE_LOOKUP)) goto permission_denied; } else if (mask & MAY_READ) { - if (!(access & AFS_ACE_READ)) + if (!(access & AFS_ACE_LOOKUP)) goto permission_denied; } else if (mask & MAY_WRITE) { if (!(access & (AFS_ACE_DELETE | /* rmdir, unlink, rename from */ - AFS_ACE_INSERT | /* create, mkdir, symlink, rename to */ - AFS_ACE_WRITE))) /* chmod */ + AFS_ACE_INSERT))) /* create, mkdir, symlink, rename to */ goto permission_denied; } else { BUG();