linux-cve-announce - CVE-2022-49796: tracing: kprobe: Fix potential null-ptr-deref on trace_array in kprobe_event_gen_test

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Message-ID: <2025050124-CVE-2022-49796-a73c@gregkh>
Date: Thu,  1 May 2025 16:09:46 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2022-49796: tracing: kprobe: Fix potential null-ptr-deref on trace_array in kprobe_event_gen_test_exit()

From: Greg Kroah-Hartman <gregkh@...nel.org>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

tracing: kprobe: Fix potential null-ptr-deref on trace_array in kprobe_event_gen_test_exit()

When test_gen_kprobe_cmd() failed after kprobe_event_gen_cmd_end(), it
will goto delete, which will call kprobe_event_delete() and release the
corresponding resource. However, the trace_array in gen_kretprobe_test
will point to the invalid resource. Set gen_kretprobe_test to NULL
after called kprobe_event_delete() to prevent null-ptr-deref.

BUG: kernel NULL pointer dereference, address: 0000000000000070
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 0 PID: 246 Comm: modprobe Tainted: G        W
6.1.0-rc1-00174-g9522dc5c87da-dirty #248
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
RIP: 0010:__ftrace_set_clr_event_nolock+0x53/0x1b0
Code: e8 82 26 fc ff 49 8b 1e c7 44 24 0c ea ff ff ff 49 39 de 0f 84 3c
01 00 00 c7 44 24 18 00 00 00 00 e8 61 26 fc ff 48 8b 6b 10 <44> 8b 65
70 4c 8b 6d 18 41 f7 c4 00 02 00 00 75 2f
RSP: 0018:ffffc9000159fe00 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88810971d268 RCX: 0000000000000000
RDX: ffff8881080be600 RSI: ffffffff811b48ff RDI: ffff88810971d058
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffc9000159fe58 R11: 0000000000000001 R12: ffffffffa0001064
R13: ffffffffa000106c R14: ffff88810971d238 R15: 0000000000000000
FS:  00007f89eeff6540(0000) GS:ffff88813b600000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000070 CR3: 000000010599e004 CR4: 0000000000330ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __ftrace_set_clr_event+0x3e/0x60
 trace_array_set_clr_event+0x35/0x50
 ? 0xffffffffa0000000
 kprobe_event_gen_test_exit+0xcd/0x10b [kprobe_event_gen_test]
 __x64_sys_delete_module+0x206/0x380
 ? lockdep_hardirqs_on_prepare+0xd8/0x190
 ? syscall_enter_from_user_mode+0x1c/0x50
 do_syscall_64+0x3f/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f89eeb061b7

The Linux kernel CVE team has assigned CVE-2022-49796 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.6 with commit 64836248dda20c8e7427b493f7e06d9bf8f58850 and fixed in 5.10.156 with commit 28a54854a95923b6266a9479ad660ca2cc0e1d5f
	Issue introduced in 5.6 with commit 64836248dda20c8e7427b493f7e06d9bf8f58850 and fixed in 5.15.80 with commit e57daa750369fedbf678346aec724a43b9a51749
	Issue introduced in 5.6 with commit 64836248dda20c8e7427b493f7e06d9bf8f58850 and fixed in 6.0.10 with commit 510c12f93674ea0a1423b24f36c67357168a262a
	Issue introduced in 5.6 with commit 64836248dda20c8e7427b493f7e06d9bf8f58850 and fixed in 6.1 with commit 22ea4ca9631eb137e64e5ab899e9c89cb6670959

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2022-49796
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	kernel/trace/kprobe_event_gen_test.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/28a54854a95923b6266a9479ad660ca2cc0e1d5f
	https://git.kernel.org/stable/c/e57daa750369fedbf678346aec724a43b9a51749
	https://git.kernel.org/stable/c/510c12f93674ea0a1423b24f36c67357168a262a
	https://git.kernel.org/stable/c/22ea4ca9631eb137e64e5ab899e9c89cb6670959