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Raphael Zimmer b282c43ed1 libceph: Fix potential out-of-bounds access in ceph_handle_auth_reply()
This patch fixes an out-of-bounds access in ceph_handle_auth_reply()
that can be triggered by a message of type CEPH_MSG_AUTH_REPLY. In
ceph_handle_auth_reply(), the value of the payload_len field of such a
message is stored in a variable of type int. A value greater than
INT_MAX leads to an integer overflow and is interpreted as a negative
value. This leads to decrementing the pointer address by this value and
subsequently accessing it because ceph_decode_need() only checks that
the memory access does not exceed the end address of the allocation.

This patch fixes the issue by changing the data type of payload_len to
u32. Additionally, the data type of result_msg_len is changed to u32,
as it is also a variable holding a non-negative length.

Also, an additional layer of sanity checks is introduced, ensuring that
directly after reading it from the message, payload_len and
result_msg_len are not greater than the overall segment length.

BUG: KASAN: slab-out-of-bounds in ceph_handle_auth_reply+0x642/0x7a0 [libceph]
Read of size 4 at addr ffff88811404df14 by task kworker/20:1/262

CPU: 20 UID: 0 PID: 262 Comm: kworker/20:1 Not tainted 6.19.2 #5 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: ceph-msgr ceph_con_workfn [libceph]
Call Trace:
 <TASK>
 dump_stack_lvl+0x76/0xa0
 print_report+0xd1/0x620
 ? __pfx__raw_spin_lock_irqsave+0x10/0x10
 ? kasan_complete_mode_report_info+0x72/0x210
 kasan_report+0xe7/0x130
 ? ceph_handle_auth_reply+0x642/0x7a0 [libceph]
 ? ceph_handle_auth_reply+0x642/0x7a0 [libceph]
 __asan_report_load_n_noabort+0xf/0x20
 ceph_handle_auth_reply+0x642/0x7a0 [libceph]
 mon_dispatch+0x973/0x23d0 [libceph]
 ? apparmor_socket_recvmsg+0x6b/0xa0
 ? __pfx_mon_dispatch+0x10/0x10 [libceph]
 ? __kasan_check_write+0x14/0x30i
 ? mutex_unlock+0x7f/0xd0
 ? __pfx_mutex_unlock+0x10/0x10
 ? __pfx_do_recvmsg+0x10/0x10 [libceph]
 ceph_con_process_message+0x1f1/0x650 [libceph]
 process_message+0x1e/0x450 [libceph]
 ceph_con_v2_try_read+0x2e48/0x6c80 [libceph]
 ? __pfx_ceph_con_v2_try_read+0x10/0x10 [libceph]
 ? save_fpregs_to_fpstate+0xb0/0x230
 ? raw_spin_rq_unlock+0x17/0xa0
 ? finish_task_switch.isra.0+0x13b/0x760
 ? __switch_to+0x385/0xda0
 ? __kasan_check_write+0x14/0x30
 ? mutex_lock+0x8d/0xe0
 ? __pfx_mutex_lock+0x10/0x10
 ceph_con_workfn+0x248/0x10c0 [libceph]
 process_one_work+0x629/0xf80
 ? __kasan_check_write+0x14/0x30
 worker_thread+0x87f/0x1570
 ? __pfx__raw_spin_lock_irqsave+0x10/0x10
 ? __pfx_try_to_wake_up+0x10/0x10
 ? kasan_print_address_stack_frame+0x1f7/0x280
 ? __pfx_worker_thread+0x10/0x10
 kthread+0x396/0x830
 ? __pfx__raw_spin_lock_irq+0x10/0x10
 ? __pfx_kthread+0x10/0x10
 ? __kasan_check_write+0x14/0x30
 ? recalc_sigpending+0x180/0x210
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x3f7/0x610
 ? __pfx_ret_from_fork+0x10/0x10
 ? __switch_to+0x385/0xda0
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1a/0x30
 </TASK>

[ idryomov: replace if statements with ceph_decode_need() for
  payload_len and result_msg_len ]

Cc: stable@vger.kernel.org
Signed-off-by: Raphael Zimmer <raphael.zimmer@tu-ilmenau.de>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2026-03-11 10:18:56 +01:00
Documentation hwmon fixes for v7.0-rc3 2026-03-07 08:39:59 -08:00
LICENSES LICENSES: Add modern form of the LGPL-2.1 tags to the usage guide section 2025-10-22 07:58:19 +02:00
arch EFI fixes for v7.0 #2 2026-03-08 12:13:09 -07:00
block block-7.0-20260305 2026-03-06 08:36:18 -08:00
certs Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
crypto crypto: testmgr - Fix stale references to aes-generic 2026-03-03 11:57:15 -08:00
drivers EFI fixes for v7.0 #2 2026-03-08 12:13:09 -07:00
fs ceph: do not skip the first folio of the next object in writeback 2026-03-09 12:34:40 +01:00
include eventpoll: Convert epoll_put_uevent() to scoped user access 2026-03-07 15:03:14 -08:00
init io_uring-7.0-20260305 2026-03-06 08:31:36 -08:00
io_uring io_uring-7.0-20260305 2026-03-06 08:31:36 -08:00
ipc Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
kernel Make clock_adjtime() syscall timex validation slightly more 2026-03-07 17:09:15 -08:00
lib linux_kselftest-kunit-fixes-7.0-rc3 2026-03-06 12:34:49 -08:00
mm drm fixes for 7.0-rc3 2026-03-06 13:29:12 -08:00
net libceph: Fix potential out-of-bounds access in ceph_handle_auth_reply() 2026-03-11 10:18:56 +01:00
rust linux_kselftest-kunit-fixes-7.0-rc3 2026-03-06 12:34:49 -08:00
samples USB / Thunderbolt changes for 7.0-rc1 2026-02-17 09:36:43 -08:00
scripts kbuild: install-extmod-build: Package resolve_btfids if necessary 2026-02-26 14:49:34 -07:00
security Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses 2026-02-22 08:26:33 -08:00
sound ASoC: Fixes for v7.0 2026-03-05 17:22:14 +01:00
tools bpf-fixes 2026-03-07 12:20:37 -08:00
usr kbuild: uapi: drop dependency on CC_CAN_LINK 2026-01-16 15:02:11 -07:00
virt KVM: always define KVM_CAP_SYNC_MMU 2026-02-28 15:31:35 +01:00
.clang-format Devicetree updates for v7.0: 2026-02-11 18:27:08 -08:00
.clippy.toml rust: clean Rust 1.88.0's warning about `clippy::disallowed_macros` configuration 2025-05-07 00:11:47 +02:00
.cocciconfig
.editorconfig editorconfig: add rst extension 2026-01-26 19:07:09 -08:00
.get_maintainer.ignore MAINTAINERS: remove Alyssa Rosenzweig 2025-09-18 21:17:31 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: kbuild: add proc macro library support 2025-11-24 17:15:36 +01:00
.mailmap linux_kselftest-kunit-fixes-7.0-rc3 2026-03-06 12:34:49 -08:00
.pylintrc docs: Move the python libraries to tools/lib/python 2025-11-18 09:22:40 -07:00
.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 Thomas Falcon from IBM ibmvnic 2026-03-05 07:35:45 -08:00
Kbuild sched: Make migrate_{en,dis}able() inline 2025-09-25 09:57:16 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS MAINTAINERS: update email address of Dongsheng Yang 2026-03-10 12:16:01 +01:00
Makefile Linux 7.0-rc3 2026-03-08 16:56:54 -07:00
README docs: add AI Coding Assistants documentation 2026-01-06 14:55:06 -07:00

README

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

The Linux kernel is the core of any Linux operating system. It manages hardware,
system resources, and provides the fundamental services for all other software.

Quick Start
-----------

* Report a bug: See Documentation/admin-guide/reporting-issues.rst
* Get the latest kernel: https://kernel.org
* Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst
* Join the community: https://lore.kernel.org/

Essential Documentation
-----------------------

All users should be familiar with:

* Building requirements: Documentation/process/changes.rst
* Code of Conduct: Documentation/process/code-of-conduct.rst
* License: See COPYING

Documentation can be built with make htmldocs or viewed online at:
https://www.kernel.org/doc/html/latest/


Who Are You?
============

Find your role below:

* New Kernel Developer - Getting started with kernel development
* Academic Researcher - Studying kernel internals and architecture
* Security Expert - Hardening and vulnerability analysis
* Backport/Maintenance Engineer - Maintaining stable kernels
* System Administrator - Configuring and troubleshooting
* Maintainer - Leading subsystems and reviewing patches
* Hardware Vendor - Writing drivers for new hardware
* Distribution Maintainer - Packaging kernels for distros
* AI Coding Assistant - LLMs and AI-powered development tools


For Specific Users
==================

New Kernel Developer
--------------------

Welcome! Start your kernel development journey here:

* Getting Started: Documentation/process/development-process.rst
* Your First Patch: Documentation/process/submitting-patches.rst
* Coding Style: Documentation/process/coding-style.rst
* Build System: Documentation/kbuild/index.rst
* Development Tools: Documentation/dev-tools/index.rst
* Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst
* Core APIs: Documentation/core-api/index.rst

Academic Researcher
-------------------

Explore the kernel's architecture and internals:

* Researcher Guidelines: Documentation/process/researcher-guidelines.rst
* Memory Management: Documentation/mm/index.rst
* Scheduler: Documentation/scheduler/index.rst
* Networking Stack: Documentation/networking/index.rst
* Filesystems: Documentation/filesystems/index.rst
* RCU (Read-Copy Update): Documentation/RCU/index.rst
* Locking Primitives: Documentation/locking/index.rst
* Power Management: Documentation/power/index.rst

Security Expert
---------------

Security documentation and hardening guides:

* Security Documentation: Documentation/security/index.rst
* LSM Development: Documentation/security/lsm-development.rst
* Self Protection: Documentation/security/self-protection.rst
* Reporting Vulnerabilities: Documentation/process/security-bugs.rst
* CVE Procedures: Documentation/process/cve.rst
* Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst
* Security Features: Documentation/userspace-api/seccomp_filter.rst

Backport/Maintenance Engineer
-----------------------------

Maintain and stabilize kernel versions:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* Backporting Guide: Documentation/process/backporting.rst
* Applying Patches: Documentation/process/applying-patches.rst
* Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git for Maintainers: Documentation/maintainer/configure-git.rst

System Administrator
--------------------

Configure, tune, and troubleshoot Linux systems:

* Admin Guide: Documentation/admin-guide/index.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst
* Tracing/Debugging: Documentation/trace/index.rst
* Performance Security: Documentation/admin-guide/perf-security.rst
* Hardware Monitoring: Documentation/hwmon/index.rst

Maintainer
----------

Lead kernel subsystems and manage contributions:

* Maintainer Handbook: Documentation/maintainer/index.rst
* Pull Requests: Documentation/maintainer/pull-requests.rst
* Managing Patches: Documentation/maintainer/modifying-patches.rst
* Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst
* Development Process: Documentation/process/maintainer-handbooks.rst
* Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git Configuration: Documentation/maintainer/configure-git.rst

Hardware Vendor
---------------

Write drivers and support new hardware:

* Driver API Guide: Documentation/driver-api/index.rst
* Driver Model: Documentation/driver-api/driver-model/driver.rst
* Device Drivers: Documentation/driver-api/infrastructure.rst
* Bus Types: Documentation/driver-api/driver-model/bus.rst
* Device Tree Bindings: Documentation/devicetree/bindings/
* Power Management: Documentation/driver-api/pm/index.rst
* DMA API: Documentation/core-api/dma-api.rst

Distribution Maintainer
-----------------------

Package and distribute the kernel:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* ABI Documentation: Documentation/ABI/README
* Kernel Configuration: Documentation/kbuild/kconfig.rst
* Module Signing: Documentation/admin-guide/module-signing.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst

AI Coding Assistant
-------------------

CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and
follow the AI coding assistants documentation before contributing to the Linux
kernel:

* Documentation/process/coding-assistants.rst

This documentation contains essential requirements about licensing, attribution,
and the Developer Certificate of Origin that all AI tools must comply with.


Communication and Support
=========================

* Mailing Lists: https://lore.kernel.org/
* IRC: #kernelnewbies on irc.oftc.net
* Bugzilla: https://bugzilla.kernel.org/
* MAINTAINERS file: Lists subsystem maintainers and mailing lists
* Email Clients: Documentation/process/email-clients.rst