Linux Kernel up to 5.10.120/5.15.45/5.17.13/5.18.2 Trailing Space ftrace privilege escalation

Summaryinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 5.10.120/5.15.45/5.17.13/5.18.2. This vulnerability affects the function ftrace of the component Trailing Space Handler. The manipulation results in an unknown weakness. This vulnerability is known as CVE-2022-49402. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.10.120/5.15.45/5.17.13/5.18.2. It has been classified as problematic. Affected is the function ftrace of the component Trailing Space Handler. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ftrace: Clean up hash direct_functions on register failures We see the following GPF when register_ftrace_direct fails: [ ] general protection fault, probably for non-canonical address \ 0x200000000000010: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [...] [ ] RIP: 0010:ftrace_find_rec_direct+0x53/0x70 [ ] Code: 48 c1 e0 03 48 03 42 08 48 8b 10 31 c0 48 85 d2 74 [...] [ ] RSP: 0018:ffffc9000138bc10 EFLAGS: 00010206 [ ] RAX: 0000000000000000 RBX: ffffffff813e0df0 RCX: 000000000000003b [ ] RDX: 0200000000000000 RSI: 000000000000000c RDI: ffffffff813e0df0 [ ] RBP: ffffffffa00a3000 R08: ffffffff81180ce0 R09: 0000000000000001 [ ] R10: ffffc9000138bc18 R11: 0000000000000001 R12: ffffffff813e0df0 [ ] R13: ffffffff813e0df0 R14: ffff888171b56400 R15: 0000000000000000 [ ] FS: 00007fa9420c7780(0000) GS:ffff888ff6a00000(0000) knlGS:000000000 [ ] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ ] CR2: 000000000770d000 CR3: 0000000107d50003 CR4: 0000000000370ee0 [ ] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ ] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ ] Call Trace: [ ] [ ] register_ftrace_direct+0x54/0x290 [ ] ? render_sigset_t+0xa0/0xa0 [ ] bpf_trampoline_update+0x3f5/0x4a0 [ ] ? 0xffffffffa00a3000 [ ] bpf_trampoline_link_prog+0xa9/0x140 [ ] bpf_tracing_prog_attach+0x1dc/0x450 [ ] bpf_raw_tracepoint_open+0x9a/0x1e0 [ ] ? find_held_lock+0x2d/0x90 [ ] ? lock_release+0x150/0x430 [ ] __sys_bpf+0xbd6/0x2700 [ ] ? lock_is_held_type+0xd8/0x130 [ ] __x64_sys_bpf+0x1c/0x20 [ ] do_syscall_64+0x3a/0x80 [ ] entry_SYSCALL_64_after_hwframe+0x44/0xae [ ] RIP: 0033:0x7fa9421defa9 [ ] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 9 f8 [...] [ ] RSP: 002b:00007ffed743bd78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 [ ] RAX: ffffffffffffffda RBX: 00000000069d2480 RCX: 00007fa9421defa9 [ ] RDX: 0000000000000078 RSI: 00007ffed743bd80 RDI: 0000000000000011 [ ] RBP: 00007ffed743be00 R08: 0000000000bb7270 R09: 0000000000000000 [ ] R10: 00000000069da210 R11: 0000000000000246 R12: 0000000000000001 [ ] R13: 00007ffed743c4b0 R14: 00000000069d2480 R15: 0000000000000001 [ ] [ ] Modules linked in: klp_vm(OK) [ ] ---[ end trace 0000000000000000 ]--- One way to trigger this is: 1. load a livepatch that patches kernel function xxx; 2. run bpftrace -e 'kfunc:xxx {}', this will fail (expected for now); 3. repeat #2 => gpf. This is because the entry is added to direct_functions, but not removed. Fix this by remove the entry from direct_functions when register_ftrace_direct fails. Also remove the last trailing space from ftrace.c, so we don't have to worry about it anymore.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2022-49402 since 02/26/2025. The exploitability is told to be difficult. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 241018 (EulerOS 2.0 SP13 : kernel (EulerOS-SA-2025-1704)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.121, 5.15.46, 5.17.14 or 5.18.3 eliminates this vulnerability. Applying the patch 82c888e51c2176a06f8b4541cf748ee81aac6e7e/cae2978d6907ef2c08b9b15f704e783f7c284713/805e87af946d8d2954171361e64d143ff37a441b/a0392833a178cf109a57c2a9d4d531bdfc6cd98f/7d54c15cb89a29a5f59e5ffc9ee62e6591769ef1 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (241018). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.120
• 5.15.0
• 5.15.1
• 5.15.2
• 5.15.3
• 5.15.4
• 5.15.5
• 5.15.6
• 5.15.7
• 5.15.8
• 5.15.9
• 5.15.10
• 5.15.11
• 5.15.12
• 5.15.13
• 5.15.14
• 5.15.15
• 5.15.16
• 5.15.17
• 5.15.18
• 5.15.19
• 5.15.20
• 5.15.21
• 5.15.22
• 5.15.23
• 5.15.24
• 5.15.25
• 5.15.26
• 5.15.27
• 5.15.28
• 5.15.29
• 5.15.30
• 5.15.31
• 5.15.32
• 5.15.33
• 5.15.34
• 5.15.35
• 5.15.36
• 5.15.37
• 5.15.38
• 5.15.39
• 5.15.40
• 5.15.41
• 5.15.42
• 5.15.43
• 5.15.44
• 5.15.45
• 5.17.0
• 5.17.1
• 5.17.2
• 5.17.3
• 5.17.4
• 5.17.5
• 5.17.6
• 5.17.7
• 5.17.8
• 5.17.9
• 5.17.10
• 5.17.11
• 5.17.12
• 5.17.13
• 5.18.0
• 5.18.1
• 5.18.2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

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CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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