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authorAndrea Parri (Microsoft) <parri.andrea@gmail.com>2020-12-09 08:08:26 +0100
committerWei Liu <wei.liu@kernel.org>2021-02-05 09:55:42 +0000
commite4d221b42354b2e2ddb9187a806afb651eee2cda (patch)
treeed8fb74205a96a8ca8c94eaccb1c8e2eec4ac5db /include/linux/hyperv.h
parente3fa4b747f085d2cda09bba0533b86fa76038635 (diff)
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Drivers: hv: vmbus: Resolve race condition in vmbus_onoffer_rescind()
An erroneous or malicious host could send multiple rescind messages for a same channel. In vmbus_onoffer_rescind(), the guest maps the channel ID to obtain a pointer to the channel object and it eventually releases such object and associated data. The host could time rescind messages and lead to an use-after-free. Add a new flag to the channel structure to make sure that only one instance of vmbus_onoffer_rescind() can get the reference to the channel object. Reported-by: Juan Vazquez <juvazq@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201209070827.29335-6-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'include/linux/hyperv.h')
-rw-r--r--include/linux/hyperv.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 2ea967bc17ad..f0d48a368f13 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -809,6 +809,7 @@ struct vmbus_channel {
u8 monitor_bit;
bool rescind; /* got rescind msg */
+ bool rescind_ref; /* got rescind msg, got channel reference */
struct completion rescind_event;
u32 ringbuffer_gpadlhandle;