kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-10-22 19:14:51 +00:00
Code Issues Releases Packages Activity
No description
1,163,179 commits 117 branches 5,803 tags 5.7 GiB
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Victor Nogueira 23c165dde8 net/sched: Abort __tc_modify_qdisc if parent class does not exist 
[ Upstream commit ffdde7bf5a ]

Lion's patch [1] revealed an ancient bug in the qdisc API.
Whenever a user creates/modifies a qdisc specifying as a parent another
qdisc, the qdisc API will, during grafting, detect that the user is
not trying to attach to a class and reject. However grafting is
performed after qdisc_create (and thus the qdiscs' init callback) is
executed. In qdiscs that eventually call qdisc_tree_reduce_backlog
during init or change (such as fq, hhf, choke, etc), an issue
arises. For example, executing the following commands:

sudo tc qdisc add dev lo root handle a: htb default 2
sudo tc qdisc add dev lo parent a: handle beef fq

Qdiscs such as fq, hhf, choke, etc unconditionally invoke
qdisc_tree_reduce_backlog() in their control path init() or change() which
then causes a failure to find the child class; however, that does not stop
the unconditional invocation of the assumed child qdisc's qlen_notify with
a null class. All these qdiscs make the assumption that class is non-null.

The solution is ensure that qdisc_leaf() which looks up the parent
class, and is invoked prior to qdisc_create(), should return failure on
not finding the class.
In this patch, we leverage qdisc_leaf to return ERR_PTRs whenever the
parentid doesn't correspond to a class, so that we can detect it
earlier on and abort before qdisc_create is called.

[1] https://lore.kernel.org/netdev/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com/

Fixes: 5e50da01d0 ("[NET_SCHED]: Fix endless loops (part 2): "simple" qdiscs")
Reported-by: syzbot+d8b58d7b0ad89a678a16@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/68663c93.a70a0220.5d25f.0857.GAE@google.com/
Reported-by: syzbot+5eccb463fa89309d8bdc@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/68663c94.a70a0220.5d25f.0858.GAE@google.com/
Reported-by: syzbot+1261670bbdefc5485a06@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/686764a5.a00a0220.c7b3.0013.GAE@google.com/
Reported-by: syzbot+15b96fc3aac35468fe77@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/686764a5.a00a0220.c7b3.0014.GAE@google.com/
Reported-by: syzbot+4dadc5aecf80324d5a51@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/68679e81.a70a0220.29cf51.0016.GAE@google.com/
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20250707210801.372995-1-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2025-07-17 18:32:06 +02:00
arch x86/CPU/AMD: Properly check the TSA microcode 2025-07-14 15:54:48 +02:00
block scsi: sd_zbc: block: Respect bio vector limits for REPORT ZONES buffer 2025-05-22 14:10:06 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2025-04-25 10:44:04 +02:00
crypto crypto: xts - Only add ecb if it is not already there 2025-06-27 11:07:06 +01:00
Documentation x86/bugs: Add a Transient Scheduler Attacks mitigation 2025-07-10 15:59:54 +02:00
drivers net: phy: smsc: Fix link failure in forced mode with Auto-MDIX 2025-07-17 18:32:05 +02:00
fs fix proc_sys_compare() handling of in-lookup dentries 2025-07-17 18:32:05 +02:00
include x86/bugs: Add a Transient Scheduler Attacks mitigation 2025-07-10 15:59:54 +02:00
init sched/isolation: Make CONFIG_CPU_ISOLATION depend on CONFIG_SMP 2025-05-02 07:47:04 +02:00
io_uring io_uring/kbuf: account ring io_buffer_list memory 2025-07-06 10:58:04 +02:00
ipc ipc: fix to protect IPCS lookups using RCU 2025-06-27 11:07:30 +01:00
kernel perf: Revert to requiring CAP_SYS_ADMIN for uprobes 2025-07-17 18:32:04 +02:00
lib lib: test_objagg: Set error message in check_expect_hints_stats() 2025-07-10 15:59:48 +02:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm/huge_memory: fix dereferencing invalid pmd migration entry 2025-06-27 11:07:38 +01:00
net net/sched: Abort __tc_modify_qdisc if parent class does not exist 2025-07-17 18:32:06 +02:00
rust rust: module: place cleanup_module() in .exit.text section 2025-07-06 10:57:54 +02:00
samples samples/bpf: Fix compilation failure for samples/bpf on LoongArch Fedora 2025-06-04 14:40:02 +02:00
scripts kbuild: Add KBUILD_CPPFLAGS to as-option invocation 2025-06-27 11:07:24 +01:00
security selinux: fix selinux_xfrm_alloc_user() to set correct ctx_len 2025-06-27 11:07:37 +01:00
sound ASoC: fsl_asrc: use internal measured ratio for non-ideal ratio mode 2025-07-17 18:32:04 +02:00
tools libbpf: Fix null pointer dereference in btf_dump__free on allocation failure 2025-07-06 10:58:00 +02:00
usr kbuild: hdrcheck: fix cross build with clang 2025-06-27 11:07:25 +01:00
virt KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() 2024-06-27 13:46:21 +02:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.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: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Remove *.orig pattern from .gitignore 2024-10-17 15:21:15 +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 sign-file,extract-cert: move common SSL helper functions to a header 2025-04-25 10:44:04 +02:00
Makefile Linux 6.1.145 2025-07-14 15:54:48 +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.