From: Christoph Hellwig <hch@lst.de> mainline inclusion from mainline-v5.11-rc4 commit 01ea173e103edd5ec41acec65b9261b87e123fc2 category: bugfix bugzilla: 185881 https://gitee.com/openeuler/kernel/issues/I4DDEL CVE: CVE-2021-4037 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------- XFS always inherits the SGID bit if it is set on the parent inode, while the generic inode_init_owner does not do this in a few cases where it can create a possible security problem, see commit 0fa3ecd87848 ("Fix up non-directory creation in SGID directories") for details. Switch XFS to use the generic helper for the normal path to fix this, just keeping the simple field inheritance open coded for the case of the non-sgid case with the bsdgrpid mount option. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> conflicts: fs/xfs/xfs_inode.c Signed-off-by: Guo Xuenan <guoxuenan@huawei.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- fs/xfs/xfs_inode.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index 64b8408af9f1..af54224ebbe7 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -802,6 +802,7 @@ xfs_ialloc( xfs_buf_t **ialloc_context, xfs_inode_t **ipp) { + struct inode *dir = pip ? VFS_I(pip) : NULL; struct xfs_mount *mp = tp->t_mountp; xfs_ino_t ino; xfs_inode_t *ip; @@ -847,18 +848,17 @@ xfs_ialloc( return error; ASSERT(ip != NULL); inode = VFS_I(ip); - inode->i_mode = mode; set_nlink(inode, nlink); - inode->i_uid = current_fsuid(); inode->i_rdev = rdev; ip->i_d.di_projid = prid; - if (pip && XFS_INHERIT_GID(pip)) { - inode->i_gid = VFS_I(pip)->i_gid; - if ((VFS_I(pip)->i_mode & S_ISGID) && S_ISDIR(mode)) - inode->i_mode |= S_ISGID; + if (dir && !(dir->i_mode & S_ISGID) && + (mp->m_flags & XFS_MOUNT_GRPID)) { + inode->i_uid = current_fsuid(); + inode->i_gid = dir->i_gid; + inode->i_mode = mode; } else { - inode->i_gid = current_fsgid(); + inode_init_owner(inode, dir, mode); } /* -- 2.20.1