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Yu Kuai 6a440e6d04 blk-mq: fix null pointer dereference in blk_mq_clear_rq_mapping()
[ Upstream commit 76dd298094 ]

Our syzkaller report a null pointer dereference, root cause is
following:

__blk_mq_alloc_map_and_rqs
 set->tags[hctx_idx] = blk_mq_alloc_map_and_rqs
  blk_mq_alloc_map_and_rqs
   blk_mq_alloc_rqs
    // failed due to oom
    alloc_pages_node
    // set->tags[hctx_idx] is still NULL
    blk_mq_free_rqs
     drv_tags = set->tags[hctx_idx];
     // null pointer dereference is triggered
     blk_mq_clear_rq_mapping(drv_tags, ...)

This is because commit 63064be150 ("blk-mq:
Add blk_mq_alloc_map_and_rqs()") merged the two steps:

1) set->tags[hctx_idx] = blk_mq_alloc_rq_map()
2) blk_mq_alloc_rqs(..., set->tags[hctx_idx])

into one step:

set->tags[hctx_idx] = blk_mq_alloc_map_and_rqs()

Since tags is not initialized yet in this case, fix the problem by
checking if tags is NULL pointer in blk_mq_clear_rq_mapping().

Fixes: 63064be150 ("blk-mq: Add blk_mq_alloc_map_and_rqs()")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20221011142253.4015966-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-29 10:08:33 +02:00
Documentation x86/apic: Don't disable x2APIC if locked 2022-10-21 12:39:07 +02:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
arch x86/topology: Fix duplicated core ID within a package 2022-10-29 10:08:31 +02:00
block blk-mq: fix null pointer dereference in blk_mq_clear_rq_mapping() 2022-10-29 10:08:33 +02:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto crypto: akcipher - default implementation for setting a private key 2022-10-21 12:38:59 +02:00
drivers net: stmmac: Enable mac_managed_pm phylink config 2022-10-29 10:08:32 +02:00
fs erofs: shouldn't churn the mapping page for duplicated copies 2022-10-29 10:08:33 +02:00
include net: phylink: add mac_managed_pm in phylink_config structure 2022-10-29 10:08:32 +02:00
init arm64 fixes for -rc3 2022-08-26 11:32:53 -07:00
io_uring io-wq: Fix memory leak in worker creation 2022-10-26 12:22:57 +02:00
ipc ipc: mqueue: fix possible memory leak in init_mqueue_fs() 2022-10-21 12:38:55 +02:00
kernel gcov: support GCC 12.1 and newer compilers 2022-10-26 12:22:57 +02:00
lib lib/Kconfig.debug: Add check for non-constant .{s,u}leb128 support to DWARF5 2022-10-21 12:39:29 +02:00
mm mm,hugetlb: take hugetlb_lock before decrementing h->resv_huge_pages 2022-10-29 10:08:30 +02:00
net skmsg: pass gfp argument to alloc_sk_msg() 2022-10-29 10:08:32 +02:00
samples Tracing updates for 5.20 / 6.0 2022-08-05 09:41:12 -07:00
scripts kbuild: rpm-pkg: fix breakage when V=1 is used 2022-10-21 12:39:01 +02:00
security selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context() 2022-10-29 10:08:29 +02:00
sound Revert "ALSA: hda: Fix page fault in snd_hda_codec_shutdown()" 2022-10-26 12:22:57 +02:00
tools perf intel-pt: Fix system_wide dummy event for hybrid 2022-10-21 12:39:26 +02:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt kvm: Add support for arch compat vm ioctls 2022-10-29 10:08:30 +02:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap Qualcomm ARM64 DTS fixes for 6.0 2022-09-23 16:44:37 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS One MAINTAINERS update, two MM fixes, both cc:stable 2022-10-01 09:13:29 -07:00
Makefile Linux 6.0.5 2022-10-26 12:53:32 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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.