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Luiz Augusto von Dentz dbf666e4fc Bluetooth: HIDP: Fix possible UAF
This fixes the following trace caused by not dropping l2cap_conn
reference when user->remove callback is called:

[   97.809249] l2cap_conn_free: freeing conn ffff88810a171c00
[   97.809907] CPU: 1 UID: 0 PID: 1419 Comm: repro_standalon Not tainted 7.0.0-rc1-dirty #14 PREEMPT(lazy)
[   97.809935] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
[   97.809947] Call Trace:
[   97.809954]  <TASK>
[   97.809961]  dump_stack_lvl (lib/dump_stack.c:122)
[   97.809990]  l2cap_conn_free (net/bluetooth/l2cap_core.c:1808)
[   97.810017]  l2cap_conn_del (./include/linux/kref.h:66 net/bluetooth/l2cap_core.c:1821 net/bluetooth/l2cap_core.c:1798)
[   97.810055]  l2cap_disconn_cfm (net/bluetooth/l2cap_core.c:7347 (discriminator 1) net/bluetooth/l2cap_core.c:7340 (discriminator 1))
[   97.810086]  ? __pfx_l2cap_disconn_cfm (net/bluetooth/l2cap_core.c:7341)
[   97.810117]  hci_conn_hash_flush (./include/net/bluetooth/hci_core.h:2152 (discriminator 2) net/bluetooth/hci_conn.c:2644 (discriminator 2))
[   97.810148]  hci_dev_close_sync (net/bluetooth/hci_sync.c:5360)
[   97.810180]  ? __pfx_hci_dev_close_sync (net/bluetooth/hci_sync.c:5285)
[   97.810212]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   97.810242]  ? up_write (./arch/x86/include/asm/atomic64_64.h:87 (discriminator 5) ./include/linux/atomic/atomic-arch-fallback.h:2852 (discriminator 5) ./include/linux/atomic/atomic-long.h:268 (discriminator 5) ./include/linux/atomic/atomic-instrumented.h:3391 (discriminator 5) kernel/locking/rwsem.c:1385 (discriminator 5) kernel/locking/rwsem.c:1643 (discriminator 5))
[   97.810267]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   97.810290]  ? rcu_is_watching (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/context_tracking.h:128 kernel/rcu/tree.c:752)
[   97.810320]  hci_unregister_dev (net/bluetooth/hci_core.c:504 net/bluetooth/hci_core.c:2716)
[   97.810346]  vhci_release (drivers/bluetooth/hci_vhci.c:691)
[   97.810375]  ? __pfx_vhci_release (drivers/bluetooth/hci_vhci.c:678)
[   97.810404]  __fput (fs/file_table.c:470)
[   97.810430]  task_work_run (kernel/task_work.c:235)
[   97.810451]  ? __pfx_task_work_run (kernel/task_work.c:201)
[   97.810472]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   97.810495]  ? do_raw_spin_unlock (./include/asm-generic/qspinlock.h:128 (discriminator 5) kernel/locking/spinlock_debug.c:142 (discriminator 5))
[   97.810527]  do_exit (kernel/exit.c:972)
[   97.810547]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   97.810574]  ? __pfx_do_exit (kernel/exit.c:897)
[   97.810594]  ? lock_acquire (kernel/locking/lockdep.c:470 (discriminator 6) kernel/locking/lockdep.c:5870 (discriminator 6) kernel/locking/lockdep.c:5825 (discriminator 6))
[   97.810616]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   97.810639]  ? do_raw_spin_lock (kernel/locking/spinlock_debug.c:95 (discriminator 4) kernel/locking/spinlock_debug.c:118 (discriminator 4))
[   97.810664]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   97.810688]  ? find_held_lock (kernel/locking/lockdep.c:5350 (discriminator 1))
[   97.810721]  do_group_exit (kernel/exit.c:1093)
[   97.810745]  get_signal (kernel/signal.c:3007 (discriminator 1))
[   97.810772]  ? security_file_permission (./arch/x86/include/asm/jump_label.h:37 security/security.c:2366)
[   97.810803]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   97.810826]  ? vfs_read (fs/read_write.c:555)
[   97.810854]  ? __pfx_get_signal (kernel/signal.c:2800)
[   97.810880]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   97.810905]  ? __pfx_vfs_read (fs/read_write.c:555)
[   97.810932]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   97.810960]  arch_do_signal_or_restart (arch/x86/kernel/signal.c:337 (discriminator 1))
[   97.810990]  ? __pfx_arch_do_signal_or_restart (arch/x86/kernel/signal.c:334)
[   97.811021]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   97.811055]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   97.811078]  ? ksys_read (fs/read_write.c:707)
[   97.811106]  ? __pfx_ksys_read (fs/read_write.c:707)
[   97.811137]  exit_to_user_mode_loop (kernel/entry/common.c:66 kernel/entry/common.c:98)
[   97.811169]  ? rcu_is_watching (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/context_tracking.h:128 kernel/rcu/tree.c:752)
[   97.811192]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   97.811215]  ? trace_hardirqs_off (./include/trace/events/preemptirq.h:36 (discriminator 33) kernel/trace/trace_preemptirq.c:95 (discriminator 33) kernel/trace/trace_preemptirq.c:90 (discriminator 33))
[   97.811240]  do_syscall_64 (./include/linux/irq-entry-common.h:226 ./include/linux/irq-entry-common.h:256 ./include/linux/entry-common.h:325 arch/x86/entry/syscall_64.c:100)
[   97.811268]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   97.811292]  ? exc_page_fault (arch/x86/mm/fault.c:1480 (discriminator 3) arch/x86/mm/fault.c:1527 (discriminator 3))
[   97.811318]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   97.811338] RIP: 0033:0x445cfe
[   97.811352] Code: Unable to access opcode bytes at 0x445cd4.

Code starting with the faulting instruction
===========================================
[   97.811360] RSP: 002b:00007f65c41c6dc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[   97.811378] RAX: fffffffffffffe00 RBX: 00007f65c41c76c0 RCX: 0000000000445cfe
[   97.811391] RDX: 0000000000000400 RSI: 00007f65c41c6e40 RDI: 0000000000000004
[   97.811403] RBP: 00007f65c41c7250 R08: 0000000000000000 R09: 0000000000000000
[   97.811415] R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffe8
[   97.811428] R13: 0000000000000000 R14: 00007fff780a8c00 R15: 00007f65c41c76c0
[   97.811453]  </TASK>
[   98.402453] ==================================================================
[   98.403560] BUG: KASAN: use-after-free in __mutex_lock (kernel/locking/mutex.c:199 kernel/locking/mutex.c:694 kernel/locking/mutex.c:776)
[   98.404541] Read of size 8 at addr ffff888113ee40a8 by task khidpd_00050004/1430
[   98.405361]
[   98.405563] CPU: 1 UID: 0 PID: 1430 Comm: khidpd_00050004 Not tainted 7.0.0-rc1-dirty #14 PREEMPT(lazy)
[   98.405588] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
[   98.405600] Call Trace:
[   98.405607]  <TASK>
[   98.405614]  dump_stack_lvl (lib/dump_stack.c:122)
[   98.405641]  print_report (mm/kasan/report.c:379 mm/kasan/report.c:482)
[   98.405667]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.405691]  ? __virt_addr_valid (arch/x86/mm/physaddr.c:55)
[   98.405724]  ? __mutex_lock (kernel/locking/mutex.c:199 kernel/locking/mutex.c:694 kernel/locking/mutex.c:776)
[   98.405748]  kasan_report (mm/kasan/report.c:221 mm/kasan/report.c:597)
[   98.405778]  ? __mutex_lock (kernel/locking/mutex.c:199 kernel/locking/mutex.c:694 kernel/locking/mutex.c:776)
[   98.405807]  __mutex_lock (kernel/locking/mutex.c:199 kernel/locking/mutex.c:694 kernel/locking/mutex.c:776)
[   98.405832]  ? do_raw_spin_lock (kernel/locking/spinlock_debug.c:95 (discriminator 4) kernel/locking/spinlock_debug.c:118 (discriminator 4))
[   98.405859]  ? l2cap_unregister_user (./include/linux/list.h:381 (discriminator 2) net/bluetooth/l2cap_core.c:1723 (discriminator 2))
[   98.405888]  ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114)
[   98.405915]  ? __pfx___mutex_lock (kernel/locking/mutex.c:775)
[   98.405939]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.405963]  ? lock_acquire (kernel/locking/lockdep.c:470 (discriminator 6) kernel/locking/lockdep.c:5870 (discriminator 6) kernel/locking/lockdep.c:5825 (discriminator 6))
[   98.405984]  ? find_held_lock (kernel/locking/lockdep.c:5350 (discriminator 1))
[   98.406015]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.406038]  ? lock_release (kernel/locking/lockdep.c:5536 kernel/locking/lockdep.c:5889 kernel/locking/lockdep.c:5875)
[   98.406061]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.406085]  ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:119 ./arch/x86/include/asm/irqflags.h:159 ./include/linux/spinlock_api_smp.h:178 kernel/locking/spinlock.c:194)
[   98.406107]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.406130]  ? __timer_delete_sync (kernel/time/timer.c:1592)
[   98.406158]  ? l2cap_unregister_user (./include/linux/list.h:381 (discriminator 2) net/bluetooth/l2cap_core.c:1723 (discriminator 2))
[   98.406186]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.406210]  l2cap_unregister_user (./include/linux/list.h:381 (discriminator 2) net/bluetooth/l2cap_core.c:1723 (discriminator 2))
[   98.406263]  hidp_session_thread (./include/linux/instrumented.h:112 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/linux/kref.h:64 net/bluetooth/hidp/core.c:996 net/bluetooth/hidp/core.c:1305)
[   98.406293]  ? __pfx_hidp_session_thread (net/bluetooth/hidp/core.c:1264)
[   98.406323]  ? kthread (kernel/kthread.c:433)
[   98.406340]  ? __pfx_hidp_session_wake_function (net/bluetooth/hidp/core.c:1251)
[   98.406370]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.406393]  ? find_held_lock (kernel/locking/lockdep.c:5350 (discriminator 1))
[   98.406424]  ? __pfx_hidp_session_wake_function (net/bluetooth/hidp/core.c:1251)
[   98.406453]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.406476]  ? trace_hardirqs_on (kernel/trace/trace_preemptirq.c:79 (discriminator 1))
[   98.406499]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.406523]  ? kthread (kernel/kthread.c:433)
[   98.406539]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.406565]  ? kthread (kernel/kthread.c:433)
[   98.406581]  ? __pfx_hidp_session_thread (net/bluetooth/hidp/core.c:1264)
[   98.406610]  kthread (kernel/kthread.c:467)
[   98.406627]  ? __pfx_kthread (kernel/kthread.c:412)
[   98.406645]  ret_from_fork (arch/x86/kernel/process.c:164)
[   98.406674]  ? __pfx_ret_from_fork (arch/x86/kernel/process.c:153)
[   98.406704]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.406728]  ? __pfx_kthread (kernel/kthread.c:412)
[   98.406747]  ret_from_fork_asm (arch/x86/entry/entry_64.S:258)
[   98.406774]  </TASK>
[   98.406780]
[   98.433693] The buggy address belongs to the physical page:
[   98.434405] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888113ee7c40 pfn:0x113ee4
[   98.435557] flags: 0x200000000000000(node=0|zone=2)
[   98.436198] raw: 0200000000000000 ffffea0004244308 ffff8881f6f3ebc0 0000000000000000
[   98.437195] raw: ffff888113ee7c40 0000000000000000 00000000ffffffff 0000000000000000
[   98.438115] page dumped because: kasan: bad access detected
[   98.438951]
[   98.439211] Memory state around the buggy address:
[   98.439871]  ffff888113ee3f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   98.440714]  ffff888113ee4000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   98.441580] >ffff888113ee4080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   98.442458]                                   ^
[   98.443011]  ffff888113ee4100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   98.443889]  ffff888113ee4180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   98.444768] ==================================================================
[   98.445719] Disabling lock debugging due to kernel taint
[   98.448074] l2cap_conn_free: freeing conn ffff88810c22b400
[   98.450012] CPU: 1 UID: 0 PID: 1430 Comm: khidpd_00050004 Tainted: G    B               7.0.0-rc1-dirty #14 PREEMPT(lazy)
[   98.450040] Tainted: [B]=BAD_PAGE
[   98.450047] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
[   98.450059] Call Trace:
[   98.450065]  <TASK>
[   98.450071]  dump_stack_lvl (lib/dump_stack.c:122)
[   98.450099]  l2cap_conn_free (net/bluetooth/l2cap_core.c:1808)
[   98.450125]  l2cap_conn_put (net/bluetooth/l2cap_core.c:1822)
[   98.450154]  session_free (net/bluetooth/hidp/core.c:990)
[   98.450181]  hidp_session_thread (net/bluetooth/hidp/core.c:1307)
[   98.450213]  ? __pfx_hidp_session_thread (net/bluetooth/hidp/core.c:1264)
[   98.450271]  ? kthread (kernel/kthread.c:433)
[   98.450293]  ? __pfx_hidp_session_wake_function (net/bluetooth/hidp/core.c:1251)
[   98.450339]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.450368]  ? find_held_lock (kernel/locking/lockdep.c:5350 (discriminator 1))
[   98.450406]  ? __pfx_hidp_session_wake_function (net/bluetooth/hidp/core.c:1251)
[   98.450442]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.450471]  ? trace_hardirqs_on (kernel/trace/trace_preemptirq.c:79 (discriminator 1))
[   98.450499]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.450528]  ? kthread (kernel/kthread.c:433)
[   98.450547]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.450578]  ? kthread (kernel/kthread.c:433)
[   98.450598]  ? __pfx_hidp_session_thread (net/bluetooth/hidp/core.c:1264)
[   98.450637]  kthread (kernel/kthread.c:467)
[   98.450657]  ? __pfx_kthread (kernel/kthread.c:412)
[   98.450680]  ret_from_fork (arch/x86/kernel/process.c:164)
[   98.450715]  ? __pfx_ret_from_fork (arch/x86/kernel/process.c:153)
[   98.450752]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[   98.450782]  ? __pfx_kthread (kernel/kthread.c:412)
[   98.450804]  ret_from_fork_asm (arch/x86/entry/entry_64.S:258)
[   98.450836]  </TASK>

Fixes: b4f34d8d9d ("Bluetooth: hidp: add new session-management helpers")
Reported-by: soufiane el hachmi <kilwa10@gmail.com>
Tested-by: soufiane el hachmi <kilwa10@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-03-12 15:27:46 -04:00
Documentation Including fixes from CAN, netfilter and wireless. 2026-03-05 11:00:46 -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 Arm: 2026-03-01 15:34:47 -08:00
block Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses 2026-02-22 08:26:33 -08:00
certs Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
crypto x509: select CONFIG_CRYPTO_LIB_SHA256 2026-02-22 12:09:23 -08:00
drivers octeontx2-af: devlink: fix NIX RAS reporter to use RAS interrupt status 2026-03-11 20:39:19 -07:00
fs rxrpc, afs: Fix missing error pointer check after rxrpc_kernel_lookup_peer() 2026-03-06 17:49:52 -08:00
include net: prevent NULL deref in ip[6]tunnel_xmit() 2026-03-12 16:03:41 +01:00
init init/Kconfig: Adjust fixed clang version for __builtin_counted_by_ref 2026-02-23 14:35:16 -08:00
io_uring io_uring-7.0-20260227 2026-02-27 10:39:11 -08:00
ipc Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
kernel tracing fixes for v7.0: 2026-03-05 08:05:05 -08:00
lib A single fix for debugobjects. 2026-03-01 13:32:32 -08:00
mm slab fixes for 7.0-rc1 2026-02-27 09:54:02 -08:00
net Bluetooth: HIDP: Fix possible UAF 2026-03-12 15:27:46 -04:00
rust rust: io: macro_export io_define_read!() and io_define_write!() 2026-02-23 00:54:02 +01:00
samples USB / Thunderbolt changes for 7.0-rc1 2026-02-17 09:36:43 -08:00
scripts Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
security Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses 2026-02-22 08:26:33 -08:00
sound ASoC: SDCA: Fix comments for sdca_irq_request() 2026-02-26 17:57:37 +01:00
tools selftests: rtnetlink: add neighbour update test 2026-03-11 19:04:55 -07:00
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 scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.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 Including fixes from CAN, netfilter and wireless. 2026-03-05 11:00:46 -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: include/net/tc_wrapper.h belongs to TC subsystem 2026-03-09 18:59:28 -07:00
Makefile Linux 7.0-rc2 2026-03-01 15:39:31 -08:00
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?
============

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* New Kernel Developer - Getting started with kernel development
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For Specific Users
==================

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--------------------

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