Draft: Drivers: vmbus: Check for channel allocation before looking up relids
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2156126
Upstream Status: https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git/ (hyperv-fixes branch)
commit 1eb65c8687316c65140b48fad27133d583178e15
Author: Mohammed Gamal <mgamal@redhat.com>
Date: Fri Feb 17 22:44:11 2023 +0200
Drivers: vmbus: Check for channel allocation before looking up relids
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.
Print a warning and error out in relid2channel() for a channel id that's invalid
in the second kernel.
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>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Link: https://lore.kernel.org/r/20230217204411.212709-1-mgamal@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Mohamed Gamal Morsy mgamal@redhat.com