From 8f5d9bed6122b8d96508436e5ad2498bb797eb6b Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 3 Jul 2025 10:30:09 +0200 Subject: [PATCH] Revert "vmci: Prevent the dispatching of uninitialized payloads" This reverts commit bfb4cf9fb97e4063f0aa62e9e398025fb6625031. While the code "looks" correct, the compiler has no way to know that doing "fun" pointer math like this really isn't a write off the end of the structure as there is no hint anywhere that the structure has data at the end of it. This causes the following build warning: In function 'fortify_memset_chk', inlined from 'ctx_fire_notification.isra' at drivers/misc/vmw_vmci/vmci_context.c:254:3: include/linux/fortify-string.h:480:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] 480 | __write_overflow_field(p_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ So revert it for now and it can come back in the future in a "sane" way that either correctly makes the structure know that there is trailing data, OR just the payload structure is properly referenced and zeroed out. Fixes: bfb4cf9fb97e ("vmci: Prevent the dispatching of uninitialized payloads") Cc: Stephen Rothwell Cc: Lizhi Xu Link: https://lore.kernel.org/r/20250703171021.0aee1482@canb.auug.org.au Signed-off-by: Greg Kroah-Hartman --- drivers/misc/vmw_vmci/vmci_context.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/misc/vmw_vmci/vmci_context.c b/drivers/misc/vmw_vmci/vmci_context.c index c60b50a24007..843f98fb17f6 100644 --- a/drivers/misc/vmw_vmci/vmci_context.c +++ b/drivers/misc/vmw_vmci/vmci_context.c @@ -251,8 +251,6 @@ static int ctx_fire_notification(u32 context_id, u32 priv_flags) ev.msg.hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID, VMCI_CONTEXT_RESOURCE_ID); ev.msg.hdr.payload_size = sizeof(ev) - sizeof(ev.msg.hdr); - memset((char*)&ev.msg.hdr + sizeof(ev.msg.hdr), 0, - ev.msg.hdr.payload_size); ev.msg.event_data.event = VMCI_EVENT_CTX_REMOVED; ev.payload.context_id = context_id; -- 2.47.2