Linux: Out-of-bounds Write
CVE-2022-50406 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 76a9234cb66479e9d02b15fd0f3e349cb2320279, 169adb79cfd59250a5b1f68cdc69e7287fc5a0ce, 82c66c46f73b88be74c869e2cbfef45281adf3c6 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 76a9234cb66479e9d02b15fd0f3e349cb2320279 or 169adb79cfd59250a5b1f68cdc69e7287fc5a0ce or 82c66c46f73b88be74c869e2cbfef45281adf3c6 or 7308591d9c7787aec58f6a01a7823f14e90db7a2, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.19.17 or 6.0.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 150d5be09ce49a9bed6feb7b7dc4e5ae188778ec up to, but not including, 76a9234cb66479e9d02b15fd0f3e349cb2320279; 150d5be09ce49a9bed6feb7b7dc4e5ae188778ec up to, but not including, 169adb79cfd59250a5b1f68cdc69e7287fc5a0ce; 150d5be09ce49a9bed6feb7b7dc4e5ae188778ec up to, but not including, 82c66c46f73b88be74c869e2cbfef45281adf3c6; 150d5be09ce49a9bed6feb7b7dc4e5ae188778ec up to, but not including, 7308591d9c7787aec58f6a01a7823f14e90db7a2; 150d5be09ce49a9bed6feb7b7dc4e5ae188778ec up to, but not including, 3d5f3ba1ac28059bdf7000cae2403e4e984308d2; 4.6 | 76a9234cb66479e9d02b15fd0f3e349cb2320279, 169adb79cfd59250a5b1f68cdc69e7287fc5a0ce, 82c66c46f73b88be74c869e2cbfef45281adf3c6, 7308591d9c7787aec58f6a01a7823f14e90db7a2, 3d5f3ba1ac28059bdf7000cae2403e4e984308d2 |
| Linux | Linux Kernel | 4.6 up to, but not including, 5.19.17; 6.0 up to, but not including, 6.0.3 | 5.19.17, 6.0.3 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: iomap: iomap: fix memory corruption when recording errors during writeback Every now and then I see this crash on arm64: Unable to handle kernel NULL pointer dereference at virtual address 00000000000000f8 Buffer I/O error on dev dm-0, logical block 8733687, async page read Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 user pgtable: 64k pages, 42-bit VAs, pgdp=0000000139750000 [00000000000000f8] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000, pmd=0000000000000000 Internal error: Oops: 96000006 [#1] PREEMPT SMP Buffer I/O error on dev dm-0, logical block 8733688, async page read Dumping ftrace buffer: Buffer I/O error on dev dm-0, logical block 8733689, async page read (ftrace buffer empty) XFS (dm-0): log I/O error -5 Modules linked in: dm_thin_pool dm_persistent_data XFS (dm-0): Metadata I/O Error (0x1) detected at xfs_trans_read_buf_map+0x1ec/0x590 [xfs] (fs/xfs/xfs_trans_buf.c:296). dm_bio_prison XFS (dm-0): Please unmount the filesystem and rectify the problem(s) XFS (dm-0): xfs_imap_lookup: xfs_ialloc_read_agi() returned error -5, agno 0 dm_bufio dm_log_writes xfs nft_chain_nat xt_REDIRECT nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip6t_REJECT potentially unexpected fatal signal 6. nf_reject_ipv6 potentially unexpected fatal signal 6. ipt_REJECT nf_reject_ipv4 CPU: 1 PID: 122166 Comm: fsstress Tainted: G W 6.0.0-rc5-djwa #rc5 3004c9f1de887ebae86015f2677638ce51ee7 rpcsec_gss_krb5 auth_rpcgss xt_tcpudp ip_set_hash_ip ip_set_hash_net xt_set nft_compat ip_set_hash_mac ip_set nf_tables Hardware name: QEMU KVM Virtual Machine, BIOS 1.5.1 06/16/2021 pstate: 60001000 (nZCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=--) ip_tables pc : 000003fd6d7df200 x_tables lr : 000003fd6d7df1ec overlay nfsv4 CPU: 0 PID: 54031 Comm: u4:3 Tainted: G W 6.0.0-rc5-djwa #rc5 3004c9f1de887ebae86015f2677638ce51ee7405 Hardware name: QEMU KVM Virtual Machine, BIOS 1.5.1 06/16/2021 Workqueue: writeback wb_workfn sp : 000003ffd9522fd0 (flush-253:0) pstate: 60401005 (nZCv daif +PAN -UAO -TCO -DIT +SSBS BTYPE=--) pc : errseq_set+0x1c/0x100 x29: 000003ffd9522fd0 x28: 0000000000000023 x27: 000002acefeb6780 x26: 0000000000000005 x25: 0000000000000001 x24: 0000000000000000 x23: 00000000ffffffff x22: 0000000000000005 lr : __filemap_set_wb_err+0x24/0xe0 x21: 0000000000000006 sp : fffffe000f80f760 x29: fffffe000f80f760 x28: 0000000000000003 x27: fffffe000f80f9f8 x26: 0000000002523000 x25: 00000000fffffffb x24: fffffe000f80f868 x23: fffffe000f80fbb0 x22: fffffc0180c26a78 x21: 0000000002530000 x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000001 x13: 0000000000470af3 x12: fffffc0058f70000 x11: 0000000000000040 x10: 0000000000001b20 x9 : fffffe000836b288 x8 : fffffc00eb9fd480 x7 : 0000000000f83659 x6 : 0000000000000000 x5 : 0000000000000869 x4 : 0000000000000005 x3 : 00000000000000f8 x20: 000003fd6d740020 x19: 000000000001dd36 x18: 0000000000000001 x17: 000003fd6d78704c x16: 0000000000000001 x15: 000002acfac87668 x2 : 0000000000000ffa x1 : 00000000fffffffb x0 : 00000000000000f8 Call trace: errseq_set+0x1c/0x100 __filemap_set_wb_err+0x24/0xe0 iomap_do_writepage+0x5e4/0xd5c write_cache_pages+0x208/0x674 iomap_writepages+0x34/0x60 xfs_vm_writepages+0x8c/0xcc [xfs 7a861f39c43631f15d3a5884246ba5035d4ca78b] x14: 0000000000000000 x13: 2064656e72757465 x12: 0000000000002180 x11: 000003fd6d8a82d0 x10: 0000000000000000 x9 : 000003fd6d8ae288 x8 : 0000000000000083 x7 : 00000000ffffffff x6 : 00000000ffffffee x5 : 00000000fbad2887 x4 : 000003fd6d9abb58 x3 : 000003fd6d740020 x2 : 0000000000000006 x1 : 000000000001dd36 x0 : 0000000000000000 CPU: ---truncated---
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Recent Out-of-bounds Write vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
Spotted an error? Tell us.