Go to file
Masami Hiramatsu 3031313eb3 kprobes: Fix to check probe enabled before disarm_kprobe_ftrace()
Commit 0cb2f1372b ("kprobes: Fix NULL pointer dereference at
kprobe_ftrace_handler") fixed one bug but not completely fixed yet.
If we run a kprobe_module.tc of ftracetest, kernel showed a warning
as below.

# ./ftracetest test.d/kprobe/kprobe_module.tc
=== Ftrace unit tests ===
[1] Kprobe dynamic event - probing module
...
[   22.400215] ------------[ cut here ]------------
[   22.400962] Failed to disarm kprobe-ftrace at trace_printk_irq_work+0x0/0x7e [trace_printk] (-2)
[   22.402139] WARNING: CPU: 7 PID: 200 at kernel/kprobes.c:1091 __disarm_kprobe_ftrace.isra.0+0x7e/0xa0
[   22.403358] Modules linked in: trace_printk(-)
[   22.404028] CPU: 7 PID: 200 Comm: rmmod Not tainted 5.9.0-rc2+ #66
[   22.404870] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014
[   22.406139] RIP: 0010:__disarm_kprobe_ftrace.isra.0+0x7e/0xa0
[   22.406947] Code: 30 8b 03 eb c9 80 3d e5 09 1f 01 00 75 dc 49 8b 34 24 89 c2 48 c7 c7 a0 c2 05 82 89 45 e4 c6 05 cc 09 1f 01 01 e8 a9 c7 f0 ff <0f> 0b 8b 45 e4 eb b9 89 c6 48 c7 c7 70 c2 05 82 89 45 e4 e8 91 c7
[   22.409544] RSP: 0018:ffffc90000237df0 EFLAGS: 00010286
[   22.410385] RAX: 0000000000000000 RBX: ffffffff83066024 RCX: 0000000000000000
[   22.411434] RDX: 0000000000000001 RSI: ffffffff810de8d3 RDI: ffffffff810de8d3
[   22.412687] RBP: ffffc90000237e10 R08: 0000000000000001 R09: 0000000000000001
[   22.413762] R10: 0000000000000000 R11: 0000000000000001 R12: ffff88807c478640
[   22.414852] R13: ffffffff8235ebc0 R14: ffffffffa00060c0 R15: 0000000000000000
[   22.415941] FS:  00000000019d48c0(0000) GS:ffff88807d7c0000(0000) knlGS:0000000000000000
[   22.417264] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   22.418176] CR2: 00000000005bb7e3 CR3: 0000000078f7a000 CR4: 00000000000006a0
[   22.419309] Call Trace:
[   22.419990]  kill_kprobe+0x94/0x160
[   22.420652]  kprobes_module_callback+0x64/0x230
[   22.421470]  notifier_call_chain+0x4f/0x70
[   22.422184]  blocking_notifier_call_chain+0x49/0x70
[   22.422979]  __x64_sys_delete_module+0x1ac/0x240
[   22.423733]  do_syscall_64+0x38/0x50
[   22.424366]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   22.425176] RIP: 0033:0x4bb81d
[   22.425741] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e0 ff ff ff f7 d8 64 89 01 48
[   22.428726] RSP: 002b:00007ffc70fef008 EFLAGS: 00000246 ORIG_RAX: 00000000000000b0
[   22.430169] RAX: ffffffffffffffda RBX: 00000000019d48a0 RCX: 00000000004bb81d
[   22.431375] RDX: 0000000000000000 RSI: 0000000000000880 RDI: 00007ffc70fef028
[   22.432543] RBP: 0000000000000880 R08: 00000000ffffffff R09: 00007ffc70fef320
[   22.433692] R10: 0000000000656300 R11: 0000000000000246 R12: 00007ffc70fef028
[   22.434635] R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000000
[   22.435682] irq event stamp: 1169
[   22.436240] hardirqs last  enabled at (1179): [<ffffffff810df542>] console_unlock+0x422/0x580
[   22.437466] hardirqs last disabled at (1188): [<ffffffff810df19b>] console_unlock+0x7b/0x580
[   22.438608] softirqs last  enabled at (866): [<ffffffff81c0038e>] __do_softirq+0x38e/0x490
[   22.439637] softirqs last disabled at (859): [<ffffffff81a00f42>] asm_call_on_stack+0x12/0x20
[   22.440690] ---[ end trace 1e7ce7e1e4567276 ]---
[   22.472832] trace_kprobe: This probe might be able to register after target module is loaded. Continue.

This is because the kill_kprobe() calls disarm_kprobe_ftrace() even
if the given probe is not enabled. In that case, ftrace_set_filter_ip()
fails because the given probe point is not registered to ftrace.

Fix to check the given (going) probe is enabled before invoking
disarm_kprobe_ftrace().

Link: https://lkml.kernel.org/r/159888672694.1411785.5987998076694782591.stgit@devnote2

Fixes: 0cb2f1372b ("kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Chengming Zhou <zhouchengming@bytedance.com>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-18 11:50:51 -04:00
Documentation ARM: SoC fixes 2020-09-13 14:54:40 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch ARM: SoC fixes 2020-09-13 14:54:40 -07:00
block - Fix a regression in bdev partition locking (Christoph) 2020-09-11 11:55:28 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2020-08-30 15:53:44 -07:00
drivers USB/Thunderbolt fixes for 5.9-rc5 2020-09-13 09:23:54 -07:00
fs Driver core fixes for 5.9-rc5 2020-09-13 09:02:59 -07:00
include Driver core fixes for 5.9-rc5 2020-09-13 09:02:59 -07:00
init init: fix error check in clean_path() 2020-09-04 09:16:58 -07:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel kprobes: Fix to check probe enabled before disarm_kprobe_ftrace() 2020-09-18 11:50:51 -04:00
lib Driver core fixes for 5.9-rc5 2020-09-13 09:02:59 -07:00
mm xen: branch for v5.9-rc4 2020-09-06 09:59:27 -07:00
net NFS client bugfixes for Linux 5.9 2020-09-09 11:14:20 -07:00
samples treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
scripts Char / Misc driver fixes for 5.9-rc5 2020-09-13 08:52:21 -07:00
security treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
sound sound fixes for 5.9-rc4 2020-09-04 12:05:25 -07:00
tools KVM/arm64 fixes for Linux 5.9, take #1 2020-09-11 13:12:11 -04:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: fix memory leak in kvm_io_bus_unregister_dev() 2020-09-11 13:15:11 -04:00
.clang-format clang-format: Update with the latest for_each macro list 2020-09-01 12:53:42 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: Add ZSTD-compressed files 2020-07-31 11:50:49 +02:00
.mailmap mailmap, MAINTAINERS: move to tycho.pizza 2020-09-08 11:29:57 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS CREDITS: Replace HTTP links with HTTPS ones 2020-07-23 14:53:58 -06:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Driver core fixes for 5.9-rc5 2020-09-13 09:02:59 -07:00
Makefile Linux 5.9-rc5 2020-09-13 16:06:00 -07:00
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.