Linux Kernel up to 5.15.82/6.0.12 io_tctx_exit_cb null pointer dereference

Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 5.15.82/6.0.12. The impacted element is the function io_tctx_exit_cb. Performing a manipulation results in null pointer dereference. This vulnerability was named CVE-2022-48983. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 5.15.82/6.0.12. This affects the function io_tctx_exit_cb. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: io_uring: Fix a null-ptr-deref in io_tctx_exit_cb() Syzkaller reports a NULL deref bug as follows: BUG: KASAN: null-ptr-deref in io_tctx_exit_cb+0x53/0xd3 Read of size 4 at addr 0000000000000138 by task file1/1955 CPU: 1 PID: 1955 Comm: file1 Not tainted 6.1.0-rc7-00103-gef4d3ea40565 #75 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 Call Trace: dump_stack_lvl+0xcd/0x134 ? io_tctx_exit_cb+0x53/0xd3 kasan_report+0xbb/0x1f0 ? io_tctx_exit_cb+0x53/0xd3 kasan_check_range+0x140/0x190 io_tctx_exit_cb+0x53/0xd3 task_work_run+0x164/0x250 ? task_work_cancel+0x30/0x30 get_signal+0x1c3/0x2440 ? lock_downgrade+0x6e0/0x6e0 ? lock_downgrade+0x6e0/0x6e0 ? exit_signals+0x8b0/0x8b0 ? do_raw_read_unlock+0x3b/0x70 ? do_raw_spin_unlock+0x50/0x230 arch_do_signal_or_restart+0x82/0x2470 ? kmem_cache_free+0x260/0x4b0 ? putname+0xfe/0x140 ? get_sigframe_size+0x10/0x10 ? do_execveat_common.isra.0+0x226/0x710 ? lockdep_hardirqs_on+0x79/0x100 ? putname+0xfe/0x140 ? do_execveat_common.isra.0+0x238/0x710 exit_to_user_mode_prepare+0x15f/0x250 syscall_exit_to_user_mode+0x19/0x50 do_syscall_64+0x42/0xb0 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0023:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 002b:00000000fffb7790 EFLAGS: 00000200 ORIG_RAX: 000000000000000b RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Kernel panic - not syncing: panic_on_warn set ... This happens because the adding of task_work from io_ring_exit_work() isn't synchronized with canceling all work items from eg exec. The execution of the two are ordered in that they are both run by the task itself, but if io_tctx_exit_cb() is queued while we're canceling all work items off exec AND gets executed when the task exits to userspace rather than in the main loop in io_uring_cancel_generic(), then we can find current->io_uring == NULL and hit the above crash. It's safe to add this NULL check here, because the execution of the two paths are done by the task itself. [axboe: add code comment and also put an explanation in the commit msg]

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2022-48983 since 08/22/2024. The exploitability is told to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 213014 (SUSE SLES15 / openSUSE 15 Security Update : kernel (SUSE-SU-2024:4315-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.15.83 or 6.0.13 eliminates this vulnerability. Applying the patch f895511de9d2/d91edca19434/998b30c3948e 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 databases at Tenable (213014) and CERT Bund (WID-SEC-2024-3251). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• NetApp StorageGRID
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• Kyocera Printer
• NetApp AFF
• NetApp ActiveIQ Unified Manager
• SUSE openSUSE
• IBM Security Guardium
• RESF Rocky Linux
• Dell NetWorker
• Dell Avamar
• IBM QRadar SIEM
• NetApp FAS
• SolarWinds Security Event Manager
• Dell PowerProtect Data Domain
• Open Source Linux Kernel
• Dell PowerScale OneFS

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 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
• 5.15.46
• 5.15.47
• 5.15.48
• 5.15.49
• 5.15.50
• 5.15.51
• 5.15.52
• 5.15.53
• 5.15.54
• 5.15.55
• 5.15.56
• 5.15.57
• 5.15.58
• 5.15.59
• 5.15.60
• 5.15.61
• 5.15.62
• 5.15.63
• 5.15.64
• 5.15.65
• 5.15.66
• 5.15.67
• 5.15.68
• 5.15.69
• 5.15.70
• 5.15.71
• 5.15.72
• 5.15.73
• 5.15.74
• 5.15.75
• 5.15.76
• 5.15.77
• 5.15.78
• 5.15.79
• 5.15.80
• 5.15.81
• 5.15.82
• 6.0.0
• 6.0.1
• 6.0.2
• 6.0.3
• 6.0.4
• 6.0.5
• 6.0.6
• 6.0.7
• 6.0.8
• 6.0.9
• 6.0.10
• 6.0.11
• 6.0.12

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

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Sourcesinfo

Entryinfo

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