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authorSean Christopherson <seanjc@google.com>2022-12-19 17:19:24 +0000
committerSean Christopherson <seanjc@google.com>2023-02-01 11:25:05 -0800
commitb1cb1fac22abf102ffeb29dd3eeca208a3869d54 (patch)
tree93f3d49ce94a62019c2ef7b461465d4d6eb197b2 /virt
parentb9926482ab91cd6dc19e28ae4f0ae98c6c1217d7 (diff)
downloadlinux-next-b1cb1fac22abf102ffeb29dd3eeca208a3869d54.tar.gz
KVM: Destroy target device if coalesced MMIO unregistration fails
Destroy and free the target coalesced MMIO device if unregistering said device fails. As clearly noted in the code, kvm_io_bus_unregister_dev() does not destroy the target device. BUG: memory leak unreferenced object 0xffff888112a54880 (size 64): comm "syz-executor.2", pid 5258, jiffies 4297861402 (age 14.129s) hex dump (first 32 bytes): 38 c7 67 15 00 c9 ff ff 38 c7 67 15 00 c9 ff ff 8.g.....8.g..... e0 c7 e1 83 ff ff ff ff 00 30 67 15 00 c9 ff ff .........0g..... backtrace: [<0000000006995a8a>] kmalloc include/linux/slab.h:556 [inline] [<0000000006995a8a>] kzalloc include/linux/slab.h:690 [inline] [<0000000006995a8a>] kvm_vm_ioctl_register_coalesced_mmio+0x8e/0x3d0 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:150 [<00000000022550c2>] kvm_vm_ioctl+0x47d/0x1600 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3323 [<000000008a75102f>] vfs_ioctl fs/ioctl.c:46 [inline] [<000000008a75102f>] file_ioctl fs/ioctl.c:509 [inline] [<000000008a75102f>] do_vfs_ioctl+0xbab/0x1160 fs/ioctl.c:696 [<0000000080e3f669>] ksys_ioctl+0x76/0xa0 fs/ioctl.c:713 [<0000000059ef4888>] __do_sys_ioctl fs/ioctl.c:720 [inline] [<0000000059ef4888>] __se_sys_ioctl fs/ioctl.c:718 [inline] [<0000000059ef4888>] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:718 [<000000006444fa05>] do_syscall_64+0x9f/0x4e0 arch/x86/entry/common.c:290 [<000000009a4ed50b>] entry_SYSCALL_64_after_hwframe+0x49/0xbe BUG: leak checking failed Fixes: 5d3c4c79384a ("KVM: Stop looking for coalesced MMIO zones if the bus is destroyed") Cc: stable@vger.kernel.org Reported-by: 柳菁峰 <liujingfeng@qianxin.com> Reported-by: Michal Luczaj <mhal@rbox.co> Link: https://lore.kernel.org/r/20221219171924.67989-1-seanjc@google.com Link: https://lore.kernel.org/all/20230118220003.1239032-1-mhal@rbox.co Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/coalesced_mmio.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 0be80c213f7f..5ef88f5a0864 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -187,15 +187,17 @@ int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
r = kvm_io_bus_unregister_dev(kvm,
zone->pio ? KVM_PIO_BUS : KVM_MMIO_BUS, &dev->dev);
+ kvm_iodevice_destructor(&dev->dev);
+
/*
* On failure, unregister destroys all devices on the
* bus _except_ the target device, i.e. coalesced_zones
- * has been modified. No need to restart the walk as
- * there aren't any zones left.
+ * has been modified. Bail after destroying the target
+ * device, there's no need to restart the walk as there
+ * aren't any zones left.
*/
if (r)
break;
- kvm_iodevice_destructor(&dev->dev);
}
}