No description
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Victor Nogueira 43d9a530c8 net/sched: ets: Remove drr class from the active list if it changes to strict
[ Upstream commit b1e125ae42 ]

Whenever a user issues an ets qdisc change command, transforming a
drr class into a strict one, the ets code isn't checking whether that
class was in the active list and removing it. This means that, if a
user changes a strict class (which was in the active list) back to a drr
one, that class will be added twice to the active list [1].

Doing so with the following commands:

tc qdisc add dev lo root handle 1: ets bands 2 strict 1
tc qdisc add dev lo parent 1:2 handle 20: \
    tbf rate 8bit burst 100b latency 1s
tc filter add dev lo parent 1: basic classid 1:2
ping -c1 -W0.01 -s 56 127.0.0.1
tc qdisc change dev lo root handle 1: ets bands 2 strict 2
tc qdisc change dev lo root handle 1: ets bands 2 strict 1
ping -c1 -W0.01 -s 56 127.0.0.1

Will trigger the following splat with list debug turned on:

[   59.279014][  T365] ------------[ cut here ]------------
[   59.279452][  T365] list_add double add: new=ffff88801d60e350, prev=ffff88801d60e350, next=ffff88801d60e2c0.
[   59.280153][  T365] WARNING: CPU: 3 PID: 365 at lib/list_debug.c:35 __list_add_valid_or_report+0x17f/0x220
[   59.280860][  T365] Modules linked in:
[   59.281165][  T365] CPU: 3 UID: 0 PID: 365 Comm: tc Not tainted 6.18.0-rc7-00105-g7e9f13163c13-dirty #239 PREEMPT(voluntary)
[   59.281977][  T365] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   59.282391][  T365] RIP: 0010:__list_add_valid_or_report+0x17f/0x220
[   59.282842][  T365] Code: 89 c6 e8 d4 b7 0d ff 90 0f 0b 90 90 31 c0 e9 31 ff ff ff 90 48 c7 c7 e0 a0 22 9f 48 89 f2 48 89 c1 4c 89 c6 e8 b2 b7 0d ff 90 <0f> 0b 90 90 31 c0 e9 0f ff ff ff 48 89 f7 48 89 44 24 10 4c 89 44
...
[   59.288812][  T365] Call Trace:
[   59.289056][  T365]  <TASK>
[   59.289224][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5
[   59.289546][  T365]  ets_qdisc_change+0xd2b/0x1e80
[   59.289891][  T365]  ? __lock_acquire+0x7e7/0x1be0
[   59.290223][  T365]  ? __pfx_ets_qdisc_change+0x10/0x10
[   59.290546][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5
[   59.290898][  T365]  ? __mutex_trylock_common+0xda/0x240
[   59.291228][  T365]  ? __pfx___mutex_trylock_common+0x10/0x10
[   59.291655][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5
[   59.291993][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5
[   59.292313][  T365]  ? trace_contention_end+0xc8/0x110
[   59.292656][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5
[   59.293022][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5
[   59.293351][  T365]  tc_modify_qdisc+0x63a/0x1cf0

Fix this by always checking and removing an ets class from the active list
when changing it to strict.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/tree/net/sched/sch_ets.c?id=ce052b9402e461a9aded599f5b47e76bc727f7de#n663

Fixes: cd9b50adc6 ("net/sched: ets: fix crash when flipping from 'strict' to 'quantum'")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/20251208190125.1868423-1-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2026-01-02 12:56:47 +01:00
arch x86/microcode: Mark early_parse_cmdline() as __init 2026-01-02 12:56:39 +01:00
block block: Use RCU in blk_mq_[un]quiesce_tagset() instead of set->tag_list_lock 2025-12-18 14:03:40 +01:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: ahash - Zero positive err value in ahash_update_finish 2025-12-18 14:03:12 +01:00
Documentation docs: hwmon: fix link to g762 devicetree binding 2025-12-18 14:03:38 +01:00
drivers broadcom: b44: prevent uninitialized value usage 2026-01-02 12:56:46 +01:00
fs gfs2: Fix use of bio_chain 2026-01-02 12:56:43 +01:00
include
init printk changes for 6.18 2025-10-04 11:13:11 -07:00
io_uring io_uring/kbuf: use READ_ONCE() for userspace-mapped memory 2025-12-18 14:03:36 +01:00
ipc namespace-6.18-rc1 2025-09-29 11:20:29 -07:00
kernel livepatch: Match old_sympos 0 and 1 in klp_find_func() 2026-01-02 12:56:39 +01:00
lib
LICENSES
mm shmem: fix recovery on rename failures 2026-01-02 12:56:37 +01:00
net
rust rust: Add -fno-isolate-erroneous-paths-dereference to bindgen_skip_c_flags 2025-11-10 08:37:06 +08:00
samples samples: work around glibc redefining some of our defines wrong 2025-11-21 09:29:02 -08:00
scripts kbuild: Use objtree for module signing key path 2026-01-02 12:56:40 +01:00
security landlock: Fix handling of disconnected directories 2025-12-18 14:03:27 +01:00
sound ALSA: wavefront: Fix integer overflow in sample size validation 2025-12-18 14:03:43 +01:00
tools selftests: netfilter: prefer xfail in case race wasn't triggered 2026-01-02 12:56:47 +01:00
usr gen_init_cpio: Ignore fsync() returning EINVAL on pipes 2025-10-07 09:53:05 -07:00
virt
.clang-format memblock: drop for_each_free_mem_pfn_range_in_zone_from() 2025-09-14 08:49:03 +03:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore
.mailmap 8 hotfixes. 4 are cc:stable, 7 are against mm/. 2025-11-26 12:38:05 -08:00
.pylintrc tools: docs: parse-headers.py: move it from sphinx dir 2025-08-29 15:54:42 -06:00
.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: mark ISDN subsystem as orphan 2025-10-27 17:49:45 -07:00
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
Makefile Linux 6.18.2 2025-12-18 14:03:43 +01:00
README README: Fix spelling 2024-03-18 03:36:32 -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 reStructuredText 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.