On Tue, 31 Aug 2004 01:15:40 +0100 Richard Mortimer <richm@oldelvet.org.uk> wrote: > I'm seeing problems with lvm on sparc64. I have a reproducible test case > using snapshots where I can reliably reproduce an error similar to > > Trying to vfree() nonexistent vm area (0000000140072000) For once it's not sparc64's fault, it's a bug in the generic LVM ioctl handling :-) It saves both pointers, clobbers the userspace copy, then only restores one of the two pointers correctly. Easy to fix, see below. Marcelo, please apply, thanks. # This is a BitKeeper generated diff -Nru style patch. # # ChangeSet # 2004/08/30 17:24:05-07:00 davem@nuts.davemloft.net # [LVM]: Do not forget to restore both user pointers. # # This in particular can make compatability layers # crash, and it is a bug for regular applications # too. # # Signed-off-by: David S. Miller <davem@davemloft.net> # # drivers/md/lvm.c # 2004/08/30 17:23:48-07:00 davem@nuts.davemloft.net +12 -0 # [LVM]: Do not forget to restore both user pointers. # # This in particular can make compatability layers # crash, and it is a bug for regular applications # too. # # Signed-off-by: David S. Miller <davem@davemloft.net> # diff -Nru a/drivers/md/lvm.c b/drivers/md/lvm.c --- a/drivers/md/lvm.c 2004-08-30 17:24:13 -07:00 +++ b/drivers/md/lvm.c 2004-08-30 17:24:13 -07:00 @@ -2689,6 +2689,10 @@ (&lv_status_byname_req.lv->lv_current_pe, &saved_ptr1, sizeof(void *)) != 0) return -EFAULT; + if (copy_to_user + (&lv_status_byname_req.lv->lv_block_exception, + &saved_ptr2, sizeof(void *)) != 0) + return -EFAULT; return 0; } } @@ -2743,6 +2747,10 @@ (&lv_status_byindex_req.lv->lv_current_pe, &saved_ptr1, sizeof(void *)) != 0) return -EFAULT; + if (copy_to_user + (&lv_status_byindex_req.lv->lv_block_exception, &saved_ptr2, + sizeof(void *)) != 0) + return -EFAULT; return 0; } /* lvm_do_lv_status_byindex() */ @@ -2799,6 +2807,10 @@ /* Restore usermode pointers */ if (copy_to_user (&lv_status_bydev_req.lv->lv_current_pe, &saved_ptr1, + sizeof(void *)) != 0) + return -EFAULT; + if (copy_to_user + (&lv_status_bydev_req.lv->lv_block_exception, &saved_ptr2, sizeof(void *)) != 0) return -EFAULT; _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
