linux-kernel - [PATCH v8 16/32] vfs: make chroot retry once on ESTALE error

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1351341219-17837-17-git-send-email-jlayton@redhat.com>
Date:	Sat, 27 Oct 2012 08:33:23 -0400
From:	Jeff Layton <jlayton@...hat.com>
To:	viro@...iv.linux.org.uk
Cc:	linux-fsdevel@...r.kernel.org, linux-nfs@...r.kernel.org,
	linux-kernel@...r.kernel.org, michael.brantley@...haw.com,
	hch@...radead.org, miklos@...redi.hu, pstaubach@...grid.com
Subject: [PATCH v8 16/32] vfs: make chroot retry once on ESTALE error

Signed-off-by: Jeff Layton <jlayton@...hat.com>
---
 fs/open.c | 37 +++++++++++++++++++++----------------
 1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/fs/open.c b/fs/open.c
index 5c2a973..a1331f1 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -434,27 +434,32 @@ SYSCALL_DEFINE1(chroot, const char __user *, filename)
 {
 	struct path path;
 	int error;
+	int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
+	unsigned int try = 0;
 
-	error = user_path_dir(filename, &path);
-	if (error)
-		goto out;
+	do {
+		error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
+		if (error)
+			break;
 
-	error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
-	if (error)
-		goto dput_and_out;
+		error = inode_permission(path.dentry->d_inode,
+					 MAY_EXEC | MAY_CHDIR);
+		if (error)
+			goto dput_and_out;
 
-	error = -EPERM;
-	if (!capable(CAP_SYS_CHROOT))
-		goto dput_and_out;
-	error = security_path_chroot(&path);
-	if (error)
-		goto dput_and_out;
+		error = -EPERM;
+		if (!capable(CAP_SYS_CHROOT))
+			goto dput_and_out;
+		error = security_path_chroot(&path);
+		if (error)
+			goto dput_and_out;
 
-	set_fs_root(current->fs, &path);
-	error = 0;
+		set_fs_root(current->fs, &path);
+		error = 0;
 dput_and_out:
-	path_put(&path);
-out:
+		path_put(&path);
+		lookup_flags |= LOOKUP_REVAL;
+	} while (retry_estale(error, try++));
 	return error;
 }
 
-- 
1.7.11.7

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/