Re: FAILED: patch "[PATCH] scsi: fnic: fix invalid stack access" failed to apply to 4.9-stable tree

[Sasha Levin <sashal@kernel.org>]

On Sun, Jan 19, 2020 at 02:43:27PM +0100, gregkh@linuxfoundation.org wrote:
>
>The patch below does not apply to the 4.9-stable tree.
>If someone wants it applied there, or to any other stable or longterm
>tree, then please email the backport, including the original git commit
>id to <stable@vger.kernel.org>.
>
>thanks,
>
>greg k-h
>
>------------------ original commit in Linus's tree ------------------
>
>From 42ec15ceaea74b5f7a621fc6686cbf69ca66c4cf Mon Sep 17 00:00:00 2001
>From: Arnd Bergmann <arnd@arndb.de>
>Date: Tue, 7 Jan 2020 21:15:49 +0100
>Subject: [PATCH] scsi: fnic: fix invalid stack access
>
>gcc -O3 warns that some local variables are not properly initialized:
>
>drivers/scsi/fnic/vnic_dev.c: In function 'fnic_dev_hang_notify':
>drivers/scsi/fnic/vnic_dev.c:511:16: error: 'a0' is used uninitialized in this function [-Werror=uninitialized]
>  vdev->args[0] = *a0;
>  ~~~~~~~~~~~~~~^~~~~
>drivers/scsi/fnic/vnic_dev.c:691:6: note: 'a0' was declared here
>  u64 a0, a1;
>      ^~
>drivers/scsi/fnic/vnic_dev.c:512:16: error: 'a1' is used uninitialized in this function [-Werror=uninitialized]
>  vdev->args[1] = *a1;
>  ~~~~~~~~~~~~~~^~~~~
>drivers/scsi/fnic/vnic_dev.c:691:10: note: 'a1' was declared here
>  u64 a0, a1;
>          ^~
>drivers/scsi/fnic/vnic_dev.c: In function 'fnic_dev_mac_addr':
>drivers/scsi/fnic/vnic_dev.c:512:16: error: 'a1' is used uninitialized in this function [-Werror=uninitialized]
>  vdev->args[1] = *a1;
>  ~~~~~~~~~~~~~~^~~~~
>drivers/scsi/fnic/vnic_dev.c:698:10: note: 'a1' was declared here
>  u64 a0, a1;
>          ^~
>
>Apparently the code relies on the local variables occupying adjacent memory
>locations in the same order, but this is of course not guaranteed.
>
>Use an array of two u64 variables where needed to make it work correctly.
>
>I suspect there is also an endianness bug here, but have not digged in deep
>enough to be sure.
>
>Fixes: 5df6d737dd4b ("[SCSI] fnic: Add new Cisco PCI-Express FCoE HBA")
>Fixes: mmtom ("init/Kconfig: enable -O3 for all arches")
>Cc: stable@vger.kernel.org
>Link: https://lore.kernel.org/r/20200107201602.4096790-1-arnd@arndb.de
>Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

I've grabbed 36fe90b0f0bd ("scsi: fnic: use kernel's '%pM' format option
to print MAC") to resolve this conflict and queued both for 4.9 and 4.4

-- 
Thanks,
Sasha