Main-line Linux kernel tree http://www.kernel.org
Go to file
Yunfei Wang dcdb3ba7e2 iommu/iova: Fix alloc iova overflows issue
In __alloc_and_insert_iova_range, there is an issue that retry_pfn
overflows. The value of iovad->anchor.pfn_hi is ~0UL, then when
iovad->cached_node is iovad->anchor, curr_iova->pfn_hi + 1 will
overflow. As a result, if the retry logic is executed, low_pfn is
updated to 0, and then new_pfn < low_pfn returns false to make the
allocation successful.

This issue occurs in the following two situations:
1. The first iova size exceeds the domain size. When initializing
iova domain, iovad->cached_node is assigned as iovad->anchor. For
example, the iova domain size is 10M, start_pfn is 0x1_F000_0000,
and the iova size allocated for the first time is 11M. The
following is the log information, new->pfn_lo is smaller than
iovad->cached_node.

Example log as follows:
[  223.798112][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range
start_pfn:0x1f0000,retry_pfn:0x0,size:0xb00,limit_pfn:0x1f0a00
[  223.799590][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range
success start_pfn:0x1f0000,new->pfn_lo:0x1efe00,new->pfn_hi:0x1f08ff

2. The node with the largest iova->pfn_lo value in the iova domain
is deleted, iovad->cached_node will be updated to iovad->anchor,
and then the alloc iova size exceeds the maximum iova size that can
be allocated in the domain.

After judging that retry_pfn is less than limit_pfn, call retry_pfn+1
to fix the overflow issue.

Signed-off-by: jianjiao zeng <jianjiao.zeng@mediatek.com>
Signed-off-by: Yunfei Wang <yf.wang@mediatek.com>
Cc: <stable@vger.kernel.org> # 5.15.*
Fixes: 4e89dce725 ("iommu/iova: Retry from last rb tree node if iova search fails")
Acked-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20230111063801.25107-1-yf.wang@mediatek.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-01-13 13:46:31 +01:00
arch powerpc fixes for 6.2 #2 2023-01-08 06:55:08 -07:00
block
certs
crypto
Documentation
drivers iommu/iova: Fix alloc iova overflows issue 2023-01-13 13:46:31 +01:00
fs NFS client fixes for Linux 6.2 2023-01-07 10:38:11 -08:00
include NFS client fixes for Linux 6.2 2023-01-07 10:38:11 -08:00
init
io_uring
ipc
kernel
lib
LICENSES
mm
net NFS client fixes for Linux 6.2 2023-01-07 10:38:11 -08:00
rust
samples
scripts
security
sound
tools memblock: small fixes in kernel-doc and tests 2023-01-08 02:54:24 -08:00
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
.rustfmt.toml
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile Linux 6.2-rc3 2023-01-08 11:49:43 -06:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.