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[Qemu-devel] [PATCH] blockdev: check dinfo ptr before using
From: |
Ryan Harper |
Subject: |
[Qemu-devel] [PATCH] blockdev: check dinfo ptr before using |
Date: |
Wed, 8 Dec 2010 10:05:00 -0600 |
User-agent: |
Mutt/1.5.6+20040907i |
If a user decides to punish a guest by revoking its block device via
drive_del, and subsequently also attempts to remove the pci device
backing it, and the device is using blockdev_auto_del() then we get a
segfault when we attempt to access dinfo->auto_del.[1]
The fix is to check if drive_get_by_blockdev() actually returns a valid
dinfo pointer or not.
1. (qemu) pci_add auto storage
file=images/test01.raw,if=virtio,id=block1,snapshot=on
(qemu) drive_del block1
(qemu) pci_del 5
*segfault*
Signed-off-by: Ryan Harper <address@hidden>
--
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
address@hidden
diff --git a/blockdev.c b/blockdev.c
index f6ac439..3b3b82d 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -30,14 +30,16 @@ void blockdev_mark_auto_del(BlockDriverState *bs)
{
DriveInfo *dinfo = drive_get_by_blockdev(bs);
- dinfo->auto_del = 1;
+ if (dinfo) {
+ dinfo->auto_del = 1;
+ }
}
void blockdev_auto_del(BlockDriverState *bs)
{
DriveInfo *dinfo = drive_get_by_blockdev(bs);
- if (dinfo->auto_del) {
+ if (dinfo && dinfo->auto_del) {
drive_uninit(dinfo);
}
}
- [Qemu-devel] [PATCH] blockdev: check dinfo ptr before using,
Ryan Harper <=