The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x b2dd05f107b11966e26fe52a313b418364cf497b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2023071608-regain-untapped-0931@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: b2dd05f107b1 ("ovl: let helper ovl_i_path_real() return the realinode") e67fe63341b8 ("fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap") 9452e93e6dae ("fs: port privilege checking helpers to mnt_idmap") f2d40141d5d9 ("fs: port inode_init_owner() to mnt_idmap") 4609e1f18e19 ("fs: port ->permission() to pass mnt_idmap") 13e83a4923be ("fs: port ->set_acl() to pass mnt_idmap") 77435322777d ("fs: port ->get_acl() to pass mnt_idmap") 011e2b717b1b ("fs: port ->tmpfile() to pass mnt_idmap") 5ebb29bee8d5 ("fs: port ->mknod() to pass mnt_idmap") c54bd91e9eab ("fs: port ->mkdir() to pass mnt_idmap") 7a77db95511c ("fs: port ->symlink() to pass mnt_idmap") 6c960e68aaed ("fs: port ->create() to pass mnt_idmap") b74d24f7a74f ("fs: port ->getattr() to pass mnt_idmap") c1632a0f1120 ("fs: port ->setattr() to pass mnt_idmap") abf08576afe3 ("fs: port vfs_*() helpers to struct mnt_idmap") 6022ec6ee2c3 ("Merge tag 'ntfs3_for_6.2' of https://github.com/Paragon-Software-Group/linux-ntfs3";) thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b2dd05f107b11966e26fe52a313b418364cf497b Mon Sep 17 00:00:00 2001 From: Zhihao Cheng <chengzhihao1@xxxxxxxxxx> Date: Tue, 16 May 2023 22:16:17 +0800 Subject: [PATCH] ovl: let helper ovl_i_path_real() return the realinode Let helper ovl_i_path_real() return the realinode to prepare for checking non-null realinode in RCU walking path. [msz] Use d_inode_rcu() since we are depending on the consitency between dentry and inode being non-NULL in an RCU setting. Signed-off-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx> Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> Fixes: ffa5723c6d25 ("ovl: store lower path in ovl_inode") Cc: <stable@xxxxxxxxxxxxxxx> # v5.19 Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx> diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 4d0b278f5630..7398de332527 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -382,7 +382,7 @@ enum ovl_path_type ovl_path_type(struct dentry *dentry); void ovl_path_upper(struct dentry *dentry, struct path *path); void ovl_path_lower(struct dentry *dentry, struct path *path); void ovl_path_lowerdata(struct dentry *dentry, struct path *path); -void ovl_i_path_real(struct inode *inode, struct path *path); +struct inode *ovl_i_path_real(struct inode *inode, struct path *path); enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); struct dentry *ovl_dentry_upper(struct dentry *dentry); diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 923d66d131c1..5a6f34c7ed03 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -250,7 +250,7 @@ struct dentry *ovl_i_dentry_upper(struct inode *inode) return ovl_upperdentry_dereference(OVL_I(inode)); } -void ovl_i_path_real(struct inode *inode, struct path *path) +struct inode *ovl_i_path_real(struct inode *inode, struct path *path) { path->dentry = ovl_i_dentry_upper(inode); if (!path->dentry) { @@ -259,6 +259,8 @@ void ovl_i_path_real(struct inode *inode, struct path *path) } else { path->mnt = ovl_upper_mnt(OVL_FS(inode->i_sb)); } + + return path->dentry ? d_inode_rcu(path->dentry) : NULL; } struct inode *ovl_inode_upper(struct inode *inode) @@ -1105,8 +1107,7 @@ void ovl_copyattr(struct inode *inode) vfsuid_t vfsuid; vfsgid_t vfsgid; - ovl_i_path_real(inode, &realpath); - realinode = d_inode(realpath.dentry); + realinode = ovl_i_path_real(inode, &realpath); real_idmap = mnt_idmap(realpath.mnt); vfsuid = i_uid_into_vfsuid(real_idmap, realinode);
