github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-07 14:04:54 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph
Linux kernel source tree
1,140,713 Commits 1 Branch 933 Tags 20 GiB
C 97%
Assembly 1%
Shell 0.6%
Rust 0.5%
Python 0.4%
Other 0.3%
99dc4520b7
Go to file
Reinette Chatre 99dc4520b7 dmaengine: idxd: Let probe fail when workqueue cannot be enabled 
commit b51b75f060 upstream.

The workqueue is enabled when the appropriate driver is loaded and
disabled when the driver is removed. When the driver is removed it
assumes that the workqueue was enabled successfully and proceeds to
free allocations made during workqueue enabling.

Failure during workqueue enabling does not prevent the driver from
being loaded. This is because the error path within drv_enable_wq()
returns success unless a second failure is encountered
during the error path. By returning success it is possible to load
the driver even if the workqueue cannot be enabled and
allocations that do not exist are attempted to be freed during
driver remove.

Some examples of problematic flows:
(a)

 idxd_dmaengine_drv_probe() -> drv_enable_wq() -> idxd_wq_request_irq():
 In above flow, if idxd_wq_request_irq() fails then
 idxd_wq_unmap_portal() is called on error exit path, but
 drv_enable_wq() returns 0 because idxd_wq_disable() succeeds. The
 driver is thus loaded successfully.

 idxd_dmaengine_drv_remove()->drv_disable_wq()->idxd_wq_unmap_portal()
 Above flow on driver unload triggers the WARN in devm_iounmap() because
 the device resource has already been removed during error path of
 drv_enable_wq().

(b)

 idxd_dmaengine_drv_probe() -> drv_enable_wq() -> idxd_wq_request_irq():
 In above flow, if idxd_wq_request_irq() fails then
 idxd_wq_init_percpu_ref() is never called to initialize the percpu
 counter, yet the driver loads successfully because drv_enable_wq()
 returns 0.

 idxd_dmaengine_drv_remove()->__idxd_wq_quiesce()->percpu_ref_kill():
 Above flow on driver unload triggers a BUG when attempting to drop the
 initial ref of the uninitialized percpu ref:
 BUG: kernel NULL pointer dereference, address: 0000000000000010

Fix the drv_enable_wq() error path by returning the original error that
indicates failure of workqueue enabling. This ensures that the probe
fails when an error is encountered and the driver remove paths are only
attempted when the workqueue was enabled successfully.

Fixes: 1f2bb40337 ("dmaengine: idxd: move wq_enable() to device.c")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/e8d8116e5efa0fd14fadc5adae6ffd319f0e5ff1.1670452419.git.reinette.chatre@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24 07:24:39 +01:00
arch arm64: dts: imx8mp: correct usb clocks 2023-01-24 07:24:38 +01:00
block block: handle bio_split_to_limits() NULL return 2023-01-18 11:58:33 +01:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto crypto: tcrypt - Fix multibuffer skcipher speed test mem leak 2022-12-31 13:32:34 +01:00
Documentation dt-bindings: phy: g12a-usb3-pcie-phy: fix compatible string documentation 2023-01-24 07:24:38 +01:00
drivers dmaengine: idxd: Let probe fail when workqueue cannot be enabled 2023-01-24 07:24:39 +01:00
fs cifs: do not include page data when checking signature 2023-01-24 07:24:36 +01:00
include usb: acpi: add helper to check port lpm capability using acpi _DSM 2023-01-24 07:24:34 +01:00
init gcc: disable -Warray-bounds for gcc-11 too 2023-01-14 10:33:43 +01:00
io_uring io_uring/poll: don't reissue in case of poll race on multishot request 2023-01-24 07:24:37 +01:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel bpf: restore the ebpf program ID for BPF_AUDIT_UNLOAD and PERF_BPF_EVENT_PROG_UNLOAD 2023-01-24 07:24:37 +01:00
lib kunit: alloc_string_stream_fragment error handling bug fix 2023-01-12 12:02:41 +01:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm/MADV_COLLAPSE: don't expand collapse when vm_end is past requested end 2023-01-24 07:24:36 +01:00
net mptcp: netlink: respect v4/v6-only sockets 2023-01-24 07:24:37 +01:00
rust Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
samples samples: vfio-mdev: Fix missing pci_disable_device() in mdpy_fb_probe() 2022-12-31 13:32:42 +01:00
scripts - Handle different output of readelf on different distros running 2022-11-27 12:08:17 -08:00
security device_cgroup: Roll back to original exceptions after copy failure 2023-01-07 11:11:56 +01:00
sound ALSA: usb-audio: Fix possible NULL pointer dereference in snd_usb_pcm_has_fixed_rate() 2023-01-18 11:58:32 +01:00
tools selftests: mptcp: userspace: validate v4-v6 subflows mix 2023-01-24 07:24:37 +01:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt Merge branch 'kvm-dwmw2-fixes' into HEAD 2022-11-23 18:59:45 -05:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.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: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.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 MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
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 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
Makefile Linux 6.1.7 2023-01-18 11:58:34 +01:00
README

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.