On Fri, Nov 22, 2019 at 12:23 PM Stephen Smalley [off-list ref] wrote:

commit bda0be7ad994 ("security: make inode_follow_link RCU-walk aware")
passed down the rcu flag to the SELinux AVC, but failed to adjust the
test in slow_avc_audit() to also return -ECHILD on LSM_AUDIT_DATA_DENTRY.
Previously, we only returned -ECHILD if generating an audit record with
LSM_AUDIT_DATA_INODE since this was only relevant from inode_permission.
Move the handling of MAY_NOT_BLOCK to avc_audit() and its inlined
equivalent in selinux_inode_permission() immediately after we determine
that audit is required, and always fall back to ref-walk in this case.

Fixes: bda0be7ad994 ("security: make inode_follow_link RCU-walk aware")
Reported-by: Will Deacon <will@kernel.org>
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Stephen Smalley <redacted>
---
 security/selinux/avc.c         | 24 +++++-------------------
 security/selinux/hooks.c       | 11 +++++++----
 security/selinux/include/avc.h |  8 +++++---
 3 files changed, 17 insertions(+), 26 deletions(-)

Also merged into selinux/next, thanks.

-- 
paul moore
www.paul-moore.com