2.5.53: VFS: brelse: Trying to free free buffer

Got this in the syslog today:

VFS: brelse: Trying to free free buffer
buffer layer error at fs/buffer.c:1182

Call Trace:
 [<c014c345>] __brelse+0x35/0x40
 [<c0180efe>] ext3_htree_fill_tree+0x14e/0x240
 [<c017a809>] ext3_dx_readdir+0x99/0x1e0
 [<c015b390>] filldir64+0x0/0xf0
 [<c017a3f5>] ext3_readdir+0x465/0x490
 [<c015b390>] filldir64+0x0/0xf0
 [<c01d5258>] __blk_put_request+0xd8/0x110
 [<c01d320f>] elv_queue_empty+0x1f/0x30
 [<c01e8d8c>] choose_drive+0x1c/0x190
 [<c01e844a>] ide_do_request+0x3a/0x290
 [<c015b0ca>] vfs_readdir+0x8a/0x90
 [<c015b390>] filldir64+0x0/0xf0
 [<c015b505>] sys_getdents64+0x85/0xc4
 [<c015b390>] filldir64+0x0/0xf0
 [<c010b598>] do_IRQ+0xd8/0x160
 [<c01094e3>] syscall_call+0x7/0xb

Kernel is 2.5.53 (pulled from bk, so it might have a changeset or two applied after 2.5.53) compiled with all debug options enabled. The filesystem is on an IDE drive, ext3 with htree enabled. I'm not very sure how the error came up, I think it was during copying something from a CD-ROM. Do let me know if there is any other info I should provide.

Petru