[V3] mke2fs: prevent creation of filesystem with unsupported revision

Submitted by Eric Sandeen on May 1, 2014, 10:35 p.m.

Details

Message ID 5362CC14.2070902@redhat.com
State Accepted, archived
Headers show

Commit Message

Eric Sandeen May 1, 2014, 10:35 p.m.
From: Frank Sorenson <fsorenso@redhat.com>

It's a bit strange to accept revision levels higher than
the code creating the filesystem can understand, so don't
allow it.

At least the kernel will mount the fs readonly if it's too
high, but no other utility will touch it, so you can't
fix the error.

Just reject anything > EXT2_MAX_SUPP_REV at mkfs time.

Signed-off-by: Frank Sorenson <fsorenso@redhat.com>
[sandeen@redhat.com: Add more verbose commit log]
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---

V2: Frank did this independently, and it's better.  I forgot about
using com_err here.

V3: go back to V1's commit log for Andreas :)


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Comments

Theodore Ts'o July 4, 2014, 7:32 p.m.
On Thu, May 01, 2014 at 05:35:00PM -0500, Eric Sandeen wrote:
> From: Frank Sorenson <fsorenso@redhat.com>
> 
> It's a bit strange to accept revision levels higher than
> the code creating the filesystem can understand, so don't
> allow it.
> 
> At least the kernel will mount the fs readonly if it's too
> high, but no other utility will touch it, so you can't
> fix the error.
> 
> Just reject anything > EXT2_MAX_SUPP_REV at mkfs time.
> 
> Signed-off-by: Frank Sorenson <fsorenso@redhat.com>
> [sandeen@redhat.com: Add more verbose commit log]
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>

Thanks, applied.

					- Ted
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Patch hide | download patch | download mbox

--- a/misc/mke2fs.c	
+++ a/misc/mke2fs.c	
@@ -1684,6 +1684,11 @@  profile_error:
 					_("bad revision level - %s"), optarg);
 				exit(1);
 			}
+			if (r_opt > EXT2_MAX_SUPP_REV) {
+				com_err(program_name, EXT2_ET_REV_TOO_HIGH,
+					_("while trying to create revision %d"), r_opt);
+				exit(1);
+			}
 			fs_param.s_rev_level = r_opt;
 			break;
 		case 's':	/* deprecated */