Skip to contentSkip to conversation

xfs: add capability check to free eofblocks ioctl

PATCH Superseded Dwight Engen 4 participants 4 messages Aug 1, 2013 – Aug 2, 2013 XFS filesystem

lore
Share & tools
lore
#0 lore raw

PATCH v8 6/7 xfs: add capability check to free eofblocks ioctl

Check for CAP_SYS_ADMIN since the caller can truncate preallocated blocks from files they do not own nor have write access to. A more fine grained access check was considered: require the caller to specify their own uid/gid and to use inode_permission to check for write, but this would not catch the case of an inode not reachable via path traversal from the callers mount namespace.

Add check for read-only filesystem to free eofblocks ioctl.

---
 fs/xfs/xfs_ioctl.c | 6 ++++++
 1 file changed, 6 insertions(+)
fs/xfs/xfs_ioctl.c +6 -0
index 60d9d1e..c8f3511 100644
@@ -1620,6 +1620,12 @@ xfs_file_ioctl(
 		struct xfs_fs_eofblocks eofb;
 		struct xfs_eofblocks keofb;
 
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		if (mp->m_flags & XFS_MOUNT_RDONLY)
+			return -XFS_ERROR(EROFS);
+
 		if (copy_from_user(&eofb, arg, sizeof(eofb)))
 			return -XFS_ERROR(EFAULT);
 
Signature · 6 lines
1.8.1.4

_______________________________________________
xfs mailing list
[email protected]
http://oss.sgi.com/mailman/listinfo/xfs
Reviewed-by on v8 6/7
#1 lore raw
Quoted 11 lines · Dwight Engen

Check for CAP_SYS_ADMIN since the caller can truncate preallocated blocks from files they do not own nor have write access to. A more fine grained access check was considered: require the caller to specify their own uid/gid and to use inode_permission to check for write, but this would not catch the case of an inode not reachable via path traversal from the callers mount namespace.

Add check for read-only filesystem to free eofblocks ioctl.

---

Thanks Dwight!

Quoted 11 lines
 fs/xfs/xfs_ioctl.c | 6 ++++++
 1 file changed, 6 insertions(+)
fs/xfs/xfs_ioctl.c +0 -0
index 60d9d1e..c8f3511 100644
@@ -1620,6 +1620,12 @@ xfs_file_ioctl(
 		struct xfs_fs_eofblocks eofb;
 		struct xfs_eofblocks keofb;

fs/xfs/xfs_ioctl.c xfs_file_ioctl( · line 1631

Quoted 10 lines
fs/xfs/xfs_ioctl.c +6 -0
 
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		if (mp->m_flags & XFS_MOUNT_RDONLY)
+			return -XFS_ERROR(EROFS);
+
 		if (copy_from_user(&eofb, arg, sizeof(eofb)))
 			return -XFS_ERROR(EFAULT);
 

_______________________________________________
xfs mailing list
[email protected]
http://oss.sgi.com/mailman/listinfo/xfs

Reviewed-by on v8 6/7
#2 lore raw
In reply to Dwight Engen
Quoted 10 lines · Dwight Engen

Check for CAP_SYS_ADMIN since the caller can truncate preallocated blocks from files they do not own nor have write access to. A more fine grained access check was considered: require the caller to specify their own uid/gid and to use inode_permission to check for write, but this would not catch the case of an inode not reachable via path traversal from the callers mount namespace.

Add check for read-only filesystem to free eofblocks ioctl.

looks good.

Signature · 7 lines
Dave Chinner
[email protected]

_______________________________________________
xfs mailing list
[email protected]
http://oss.sgi.com/mailman/listinfo/xfs
Reviewed-by on v8 6/7
#3 lore raw
In reply to Dwight Engen
Quoted 11 lines · Dwight Engen

Check for CAP_SYS_ADMIN since the caller can truncate preallocated blocks from files they do not own nor have write access to. A more fine grained access check was considered: require the caller to specify their own uid/gid and to use inode_permission to check for write, but this would not catch the case of an inode not reachable via path traversal from the callers mount namespace.

Add check for read-only filesystem to free eofblocks ioctl.

---

looks good to me, thanks

Quoted 11 lines
 fs/xfs/xfs_ioctl.c | 6 ++++++
 1 file changed, 6 insertions(+)
fs/xfs/xfs_ioctl.c +0 -0
index 60d9d1e..c8f3511 100644
@@ -1620,6 +1620,12 @@ xfs_file_ioctl(
 		struct xfs_fs_eofblocks eofb;
 		struct xfs_eofblocks keofb;

fs/xfs/xfs_ioctl.c xfs_file_ioctl( · line 1631

Quoted 10 lines
fs/xfs/xfs_ioctl.c +6 -0
 
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		if (mp->m_flags & XFS_MOUNT_RDONLY)
+			return -XFS_ERROR(EROFS);
+
 		if (copy_from_user(&eofb, arg, sizeof(eofb)))
 			return -XFS_ERROR(EFAULT);
 

_______________________________________________
xfs mailing list
[email protected]
http://oss.sgi.com/mailman/listinfo/xfs