This is a note to let you know that I've just added the patch titled
fs: fix UAF/GPF bug in nilfs_mdt_destroy
to the 5.15-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:
fs-fix-uaf-gpf-bug-in-nilfs_mdt_destroy.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2e488f13755ffbb60f307e991b27024716a33b29 Mon Sep 17 00:00:00 2001
From: Dongliang Mu <mudongliangabcd@xxxxxxxxx>
Date: Tue, 16 Aug 2022 12:08:58 +0800
Subject: fs: fix UAF/GPF bug in nilfs_mdt_destroy
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
From: Dongliang Mu <mudongliangabcd@xxxxxxxxx>
commit 2e488f13755ffbb60f307e991b27024716a33b29 upstream.
In alloc_inode, inode_init_always() could return -ENOMEM if
security_inode_alloc() fails, which causes inode->i_private
uninitialized. Then nilfs_is_metadata_file_inode() returns
true and nilfs_free_inode() wrongly calls nilfs_mdt_destroy(),
which frees the uninitialized inode->i_private
and leads to crashes(e.g., UAF/GPF).
Fix this by moving security_inode_alloc just prior to
this_cpu_inc(nr_inodes)
Link: https://lkml.kernel.org/r/CAFcO6XOcf1Jj2SeGt=jJV59wmhESeSKpfR0omdFRq+J9nD1vfQ@xxxxxxxxxxxxxx
Reported-by: butt3rflyh4ck <butterflyhuangxx@xxxxxxxxx>
Reported-by: Hao Sun <sunhao.th@xxxxxxxxx>
Reported-by: Jiacheng Xu <stitch@xxxxxxxxxx>
Reviewed-by: Christian Brauner (Microsoft) <brauner@xxxxxxxxxx>
Signed-off-by: Dongliang Mu <mudongliangabcd@xxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/inode.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -167,8 +167,6 @@ int inode_init_always(struct super_block
inode->i_wb_frn_history = 0;
#endif
- if (security_inode_alloc(inode))
- goto out;
spin_lock_init(&inode->i_lock);
lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key);
@@ -205,11 +203,12 @@ int inode_init_always(struct super_block
inode->i_fsnotify_mask = 0;
#endif
inode->i_flctx = NULL;
+
+ if (unlikely(security_inode_alloc(inode)))
+ return -ENOMEM;
this_cpu_inc(nr_inodes);
return 0;
-out:
- return -ENOMEM;
}
EXPORT_SYMBOL(inode_init_always);
Patches currently in stable-queue which might be from mudongliangabcd@xxxxxxxxx are
queue-5.15/fs-fix-uaf-gpf-bug-in-nilfs_mdt_destroy.patch
