This is a note to let you know that I've just added the patch titled
lsm: fix default return value for inode_getsecctx
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
lsm-fix-default-return-value-for-inode_getsecctx.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b36995b8609a5a8fe5cf259a1ee768fcaed919f8 Mon Sep 17 00:00:00 2001
From: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
Date: Tue, 31 Oct 2023 13:32:07 +0100
Subject: lsm: fix default return value for inode_getsecctx
From: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
commit b36995b8609a5a8fe5cf259a1ee768fcaed919f8 upstream.
-EOPNOTSUPP is the return value that implements a "no-op" hook, not 0.
Without this fix having only the BPF LSM enabled (with no programs
attached) can cause uninitialized variable reads in
nfsd4_encode_fattr(), because the BPF hook returns 0 without touching
the 'ctxlen' variable and the corresponding 'contextlen' variable in
nfsd4_encode_fattr() remains uninitialized, yet being treated as valid
based on the 0 return value.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 98e828a0650f ("security: Refactor declaration of LSM hooks")
Reported-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
Signed-off-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
Signed-off-by: Paul Moore <paul@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/lsm_hook_defs.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -255,7 +255,7 @@ LSM_HOOK(void, LSM_RET_VOID, release_sec
LSM_HOOK(void, LSM_RET_VOID, inode_invalidate_secctx, struct inode *inode)
LSM_HOOK(int, 0, inode_notifysecctx, struct inode *inode, void *ctx, u32 ctxlen)
LSM_HOOK(int, 0, inode_setsecctx, struct dentry *dentry, void *ctx, u32 ctxlen)
-LSM_HOOK(int, 0, inode_getsecctx, struct inode *inode, void **ctx,
+LSM_HOOK(int, -EOPNOTSUPP, inode_getsecctx, struct inode *inode, void **ctx,
u32 *ctxlen)
#if defined(CONFIG_SECURITY) && defined(CONFIG_WATCH_QUEUE)
Patches currently in stable-queue which might be from omosnace@xxxxxxxxxx are
queue-5.10/lsm-fix-default-return-value-for-vm_enough_memory.patch
queue-5.10/lsm-fix-default-return-value-for-inode_getsecctx.patch
