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Larysa Zaremba 0fcda0c9cb xsk: always clear DMA mapping information when unmapping the pool
[ Upstream commit ac9a48a6f1 ]

When the umem is shared, the DMA mapping is also shared between the xsk
pools, therefore it should stay valid as long as at least 1 user remains.
However, the pool also keeps the copies of DMA-related information that are
initialized in the same way in xp_init_dma_info(), but cleared by
xp_dma_unmap() only for the last remaining pool, this causes the problems
below.

The first one is that the commit adbf5a4234 ("ice: remove af_xdp_zc_qps
bitmap") relies on pool->dev to determine the presence of a ZC pool on a
given queue, avoiding internal bookkeeping. This works perfectly fine if
the UMEM is not shared, but reliably fails otherwise as stated in the
linked report.

The second one is pool->dma_pages which is dynamically allocated and
only freed in xp_dma_unmap(), this leads to a small memory leak. kmemleak
does not catch it, but by printing the allocation results after terminating
the userspace program it is possible to see that all addresses except the
one belonging to the last detached pool are still accessible through the
kmemleak dump functionality.

Always clear the DMA mapping information from the pool and free
pool->dma_pages when unmapping the pool, so that the only difference
between results of the last remaining user's call and the ones before would
be the destruction of the DMA mapping.

Fixes: adbf5a4234 ("ice: remove af_xdp_zc_qps bitmap")
Fixes: 921b68692a ("xsk: Enable sharing of dma mappings")
Reported-by: Alasdair McWilliam <alasdair.mcwilliam@outlook.com>
Closes: https://lore.kernel.org/PA4P194MB10056F208AF221D043F57A3D86512@PA4P194MB1005.EURP194.PROD.OUTLOOK.COM
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Link: https://lore.kernel.org/r/20241122112912.89881-1-larysa.zaremba@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2024-12-14 19:59:47 +01:00
arch powerpc/vdso: Drop -mstack-protector-guard flags in 32-bit files with clang 2024-12-14 19:59:44 +01:00
block block, bfq: fix bfqq uaf in bfq_limit_depth() 2024-12-09 10:33:00 +01:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: pcrypt - Call crypto layer directly when padata_do_parallel() return -EBUSY 2024-12-09 10:31:48 +01:00
Documentation zram: split memory-tracking and ac-time tracking 2024-12-14 19:59:44 +01:00
drivers scsi: ufs: core: Add ufshcd_send_bsg_uic_cmd() for UFS BSG 2024-12-14 19:59:47 +01:00
fs f2fs: fix to drop all discards after creating snapshot on lvm device 2024-12-14 19:59:45 +01:00
include i3c: master: Extend address status bit to 4 and add I3C_ADDR_SLOT_EXT_DESIRED 2024-12-14 19:59:46 +01:00
init Compiler Attributes: disable __counted_by for clang < 19.1.3 2024-12-09 10:32:46 +01:00
io_uring io_uring: fix possible deadlock in io_register_iowq_max_workers() 2024-11-17 15:08:58 +01:00
ipc ipc: fix memleak if msg_init_ns failed in create_ipc_ns 2024-12-09 10:32:54 +01:00
kernel ntp: Remove invalid cast in time offset math 2024-12-14 19:59:44 +01:00
lib maple_tree: refine mas_store_root() on storing NULL 2024-12-09 10:33:04 +01:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm/slub: Avoid list corruption when removing a slab from the full list 2024-12-09 10:33:06 +01:00
net xsk: always clear DMA mapping information when unmapping the pool 2024-12-14 19:59:47 +01:00
rust rust: macros: fix documentation of the paste! macro 2024-12-09 10:32:25 +01:00
samples bpf: Fix the xdp_adjust_tail sample prog issue 2024-12-09 10:32:02 +01:00
scripts modpost: remove incorrect code in do_eisa_entry() 2024-12-09 10:32:59 +01:00
security apparmor: test: Fix memory leak for aa_unpack_strdup() 2024-12-09 10:32:45 +01:00
sound ALSA: hda/realtek: Apply quirk for Medion E15433 2024-12-09 10:32:52 +01:00
tools selftests: hid: fix typo and exit code 2024-12-14 19:59:34 +01:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt KVM: Use dedicated mutex to protect kvm_usage_count to avoid deadlock 2024-10-04 16:29:47 +02:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Remove *.orig pattern from .gitignore 2024-10-04 16:29:44 +02:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS membarrier: riscv: Add full memory barrier in switch_mm() 2024-09-12 11:11:45 +02:00
Makefile Linux 6.6.65 2024-12-11 16:13:43 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.