Subject: CVE-2021-47047: spi: spi-zynqmp-gqspi: return -ENOMEM if dma_map_single fails

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

spi: spi-zynqmp-gqspi: return -ENOMEM if dma_map_single fails

The spi controller supports 44-bit address space on AXI in DMA mode,
so set dma_addr_t width to 44-bit to avoid using a swiotlb mapping.
In addition, if dma_map_single fails, it should return immediately
instead of continuing doing the DMA operation which bases on invalid
address.

This fixes the following crash which occurs in reading a big block
from flash:

[  123.633577] zynqmp-qspi ff0f0000.spi: swiotlb buffer is full (sz: 4194304 bytes), total 32768 (slots), used 0 (slots)
[  123.644230] zynqmp-qspi ff0f0000.spi: ERR:rxdma:memory not mapped
[  123.784625] Unable to handle kernel paging request at virtual address 00000000003fffc0
[  123.792536] Mem abort info:
[  123.795313]   ESR = 0x96000145
[  123.798351]   EC = 0x25: DABT (current EL), IL = 32 bits
[  123.803655]   SET = 0, FnV = 0
[  123.806693]   EA = 0, S1PTW = 0
[  123.809818] Data abort info:
[  123.812683]   ISV = 0, ISS = 0x00000145
[  123.816503]   CM = 1, WnR = 1
[  123.819455] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000805047000
[  123.825887] [00000000003fffc0] pgd=0000000803b45003, p4d=0000000803b45003, pud=0000000000000000
[  123.834586] Internal error: Oops: 96000145 [#1] PREEMPT SMP

The Linux kernel CVE team has assigned CVE-2021-47047 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 5.10 with commit 1c26372e5aa9 and fixed in 5.10.37 with commit 5980a3b9c933
	Issue introduced in 5.10 with commit 1c26372e5aa9 and fixed in 5.11.21 with commit c26c026eb496
	Issue introduced in 5.10 with commit 1c26372e5aa9 and fixed in 5.12.4 with commit bad5a23cf2b4
	Issue introduced in 5.10 with commit 1c26372e5aa9 and fixed in 5.13 with commit 126bdb606fd2

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2021-47047
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	drivers/spi/spi-zynqmp-gqspi.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/5980a3b9c933408bc22b0e349b78c3ebd7cbf880
	https://git.kernel.org/stable/c/c26c026eb496261dbc0adbf606cc81989cd2038c
	https://git.kernel.org/stable/c/bad5a23cf2b477fa78b85fd392736dae09a1e818
	https://git.kernel.org/stable/c/126bdb606fd2802454e6048caef1be3e25dd121e