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authorDongliang Mu <mudongliangabcd@gmail.com>2022-08-16 07:08:58 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2022-09-02 00:30:24 +0300
commit2e488f13755ffbb60f307e991b27024716a33b29 (patch)
treefa967a2ec7ee9bfdfddba2f6e73f91d7bbff075c /fs/inode.c
parent568035b01cfb107af8d2e4bd2fb9aea22cf5b868 (diff)
downloadlinux-2e488f13755ffbb60f307e991b27024716a33b29.tar.xz
fs: fix UAF/GPF bug in nilfs_mdt_destroy
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@mail.gmail.com Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com> Reported-by: Hao Sun <sunhao.th@gmail.com> Reported-by: Jiacheng Xu <stitch@zju.edu.cn> Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/inode.c')
-rw-r--r--fs/inode.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/fs/inode.c b/fs/inode.c
index 6462276dfdf0..5559a2983341 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -192,8 +192,6 @@ int inode_init_always(struct super_block *sb, struct inode *inode)
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);
@@ -228,11 +226,12 @@ int inode_init_always(struct super_block *sb, struct inode *inode)
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);