Messages in this thread Patch in this message | | | From | Mohammed Gamal <> | Subject | [PATCH v2] Drivers: vmbus: Check for channel allocation before looking up relids | Date | Tue, 14 Feb 2023 13:27:41 +0200 |
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relid2channel() assumes vmbus channel array to be allocated when called. However, in cases such as kdump/kexec, not all relids will be reset by the host. When the second kernel boots and if the guest receives a vmbus interrupt during vmbus driver initialization before vmbus_connect() is called, before it finishes, or if it fails, the vmbus interrupt service routine is called which in turn calls relid2channel() and can cause a null pointer dereference.
So Make relid2channel() check if vmbus channels is allocated first, and if not print a warning and return NULL to the caller.
Fixes: 8b6a877c060e ("Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of channels")
Signed-off-by: Mohammed Gamal <mgamal@redhat.com> --- Changes from v1: * Corrected and detailed description in commit message * Added detailed warning message --- drivers/hv/connection.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index 9dc27e5d367a..82876e84f719 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -409,6 +409,10 @@ void vmbus_disconnect(void) */ struct vmbus_channel *relid2channel(u32 relid) { + if (vmbus_connection.channels == NULL) { + WARN(1, "Requested relid=%u, but channel mapping not allocated!\n", relid); + return NULL; + } if (WARN_ON(relid >= MAX_CHANNEL_RELIDS)) return NULL; return READ_ONCE(vmbus_connection.channels[relid]); -- 2.38.1
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