From c732623b0bb3631d61203e1e9f87bee34b7fd169 Mon Sep 17 00:00:00 2001 From: Tim Sell Date: Tue, 1 Mar 2016 19:45:03 -0500 Subject: [PATCH] staging: unisys: visorbus: tolerate larger-than-expected controlvm channel Use the dynamic size of the controlvm channel (struct channel_header.size) instead of the statically computed sizeof(struct controlvm_channel) when determining the valid bounds for visorchannel_read() and visorchannel_write(). This prevents an observed problem where kdump was failing because controlvm_channel.local_crash_msg_offset was pointing beyond the statically computed size of the channel, even though the channel was physically large enough. This was causing visorchannel_read() to unecessarily fail, because we thought we were attempting to access memory outside of the channel. Signed-off-by: Timothy Sell Signed-off-by: David Kershner Signed-off-by: Greg Kroah-Hartman --- drivers/staging/unisys/visorbus/visorchipset.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/staging/unisys/visorbus/visorchipset.c b/drivers/staging/unisys/visorbus/visorchipset.c index e1a5b67..166a067 100644 --- a/drivers/staging/unisys/visorbus/visorchipset.c +++ b/drivers/staging/unisys/visorbus/visorchipset.c @@ -2251,7 +2251,6 @@ visorchipset_init(struct acpi_device *acpi_device) { int rc = 0; u64 addr; - int tmp_sz = sizeof(struct spar_controlvm_channel_protocol); uuid_le uuid = SPAR_CONTROLVM_CHANNEL_PROTOCOL_UUID; addr = controlvm_get_channel_address(); @@ -2261,8 +2260,10 @@ visorchipset_init(struct acpi_device *acpi_device) memset(&busdev_notifiers, 0, sizeof(busdev_notifiers)); memset(&controlvm_payload_info, 0, sizeof(controlvm_payload_info)); - controlvm_channel = visorchannel_create_with_lock(addr, tmp_sz, + controlvm_channel = visorchannel_create_with_lock(addr, 0, GFP_KERNEL, uuid); + if (!controlvm_channel) + return -ENODEV; if (SPAR_CONTROLVM_CHANNEL_OK_CLIENT( visorchannel_get_header(controlvm_channel))) { initialize_controlvm_payload(); -- 2.7.4