5.15-stable review patch. If anyone has any objections, please let me know.
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From: Greg Kroah-Hartman gregkh@linuxfoundation.org
[ Upstream commit 8f5d9bed6122b8d96508436e5ad2498bb797eb6b ]
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 sfr@canb.auug.org.au Cc: Lizhi Xu lizhi.xu@windriver.com Link: https://lore.kernel.org/r/20250703171021.0aee1482@canb.auug.org.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 a8df60b9301c..c0b5e339d5a1 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;