# CVE-2024-49875: nfsd: map the EBADMSG to nfserr_io to avoid warning > A missing error code mapping in the Linux kernel NFS server causes a warning and potential service disruption when handling corrupted directory blocks. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 21 Oct 2024 - **Updated:** 5 Aug 2026 - **Also known as:** AZL-51207, AZL-51222, BELL-CVE-2024-49875, DEBIAN-CVE-2024-49875, GHSA-vcrj-5576-fc99, UBUNTU-CVE-2024-49875 ## What is CVE-2024-49875? CVE-2024-49875 is a high-severity denial of service vulnerability in Linux kernel, published on 21 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description In the Linux kernel, the following vulnerability has been resolved: nfsd: map the EBADMSG to nfserr_io to avoid warning Ext4 will throw -EBADMSG through ext4_readdir when a checksum error occurs, resulting in the following WARNING. Fix it by mapping EBADMSG to nfserr_io. nfsd_buffered_readdir iterate_dir // -EBADMSG -74 ext4_readdir // .iterate_shared ext4_dx_readdir ext4_htree_fill_tree htree_dirblock_to_tree ext4_read_dirblock __ext4_read_dirblock ext4_dirblock_csum_verify warn_no_space_for_csum __warn_no_space_for_csum return ERR_PTR(-EFSBADCRC) // -EBADMSG -74 nfserrno // WARNING [ 161.115610] ------------[ cut here ]------------ [ 161.116465] nfsd: non-standard errno: -74 [ 161.117315] WARNING: CPU: 1 PID: 780 at fs/nfsd/nfsproc.c:878 nfserrno+0x9d/0xd0 [ 161.118596] Modules linked in: [ 161.119243] CPU: 1 PID: 780 Comm: nfsd Not tainted 5.10.0-00014-g79679361fd5d #138 [ 161.120684] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qe mu.org 04/01/2014 [ 161.123601] RIP: 0010:nfserrno+0x9d/0xd0 [ 161.124676] Code: 0f 87 da 30 dd 00 83 e3 01 b8 00 00 00 05 75 d7 44 89 ee 48 c7 c7 c0 57 24 98 89 44 24 04 c6 05 ce 2b 61 03 01 e8 99 20 d8 00 <0f> 0b 8b 44 24 04 eb b5 4c 89 e6 48 c7 c7 a0 6d a4 99 e8 cc 15 33 [ 161.127797] RSP: 0018:ffffc90000e2f9c0 EFLAGS: 00010286 [ 161.128794] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 161.130089] RDX: 1ffff1103ee16f6d RSI: 0000000000000008 RDI: fffff520001c5f2a [ 161.131379] RBP: 0000000000000022 R08: 0000000000000001 R09: ffff8881f70c1827 [ 161.132664] R10: ffffed103ee18304 R11: 0000000000000001 R12: 0000000000000021 [ 161.133949] R13: 00000000ffffffb6 R14: ffff8881317c0000 R15: ffffc90000e2fbd8 [ 161.135244] FS: 0000000000000000(0000) GS:ffff8881f7080000(0000) knlGS:0000000000000000 [ 161.136695] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 161.137761] CR2: 00007fcaad70b348 CR3: 0000000144256006 CR4: 0000000000770ee0 [ 161.139041] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 161.140291] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 161.141519] PKRU: 55555554 [ 161.142076] Call Trace: [ 161.142575] ? __warn+0x9b/0x140 [ 161.143229] ? nfserrno+0x9d/0xd0 [ 161.143872] ? report_bug+0x125/0x150 [ 161.144595] ? handle_bug+0x41/0x90 [ 161.145284] ? exc_invalid_op+0x14/0x70 [ 161.146009] ? asm_exc_invalid_op+0x12/0x20 [ 161.146816] ? nfserrno+0x9d/0xd0 [ 161.147487] nfsd_buffered_readdir+0x28b/0x2b0 [ 161.148333] ? nfsd4_encode_dirent_fattr+0x380/0x380 [ 161.149258] ? nfsd_buffered_filldir+0xf0/0xf0 [ 161.150093] ? wait_for_concurrent_writes+0x170/0x170 [ 161.151004] ? generic_file_llseek_size+0x48/0x160 [ 161.151895] nfsd_readdir+0x132/0x190 [ 161.152606] ? nfsd4_encode_dirent_fattr+0x380/0x380 [ 161.153516] ? nfsd_unlink+0x380/0x380 [ 161.154256] ? override_creds+0x45/0x60 [ 161.155006] nfsd4_encode_readdir+0x21a/0x3d0 [ 161.155850] ? nfsd4_encode_readlink+0x210/0x210 [ 161.156731] ? write_bytes_to_xdr_buf+0x97/0xe0 [ 161.157598] ? __write_bytes_to_xdr_buf+0xd0/0xd0 [ 161.158494] ? lock_downgrade+0x90/0x90 [ 161.159232] ? nfs4svc_decode_voidarg+0x10/0x10 [ 161.160092] nfsd4_encode_operation+0x15a/0x440 [ 161.160959] nfsd4_proc_compound+0x718/0xe90 [ 161.161818] nfsd_dispatch+0x18e/0x2c0 [ 161.162586] svc_process_common+0x786/0xc50 [ 161.163403] ? nfsd_svc+0x380/0x380 [ 161.164137] ? svc_printk+0x160/0x160 [ 161.164846] ? svc_xprt_do_enqueue.part.0+0x365/0x380 [ 161.165808] ? nfsd_svc+0x380/0x380 [ 161.166523] ? rcu_is_watching+0x23/0x40 [ 161.167309] svc_process+0x1a5/0x200 [ 161.168019] nfsd+0x1f5/0x380 [ 161.168663] ? nfsd_shutdown_threads+0x260/0x260 [ 161.169554] kthread+0x1c4/0x210 [ 161.170224] ? kthread_insert_work_sanity_check+0x80/0x80 [ 161.171246] ret_from_fork+0x1f/0x30 Weakness: CWE-354 (Improper Validation of Integrity Check Value) ## Which versions are affected by CVE-2024-49875? It affects 1 product. Products: Linux kernel. ## How do I fix CVE-2024-49875? Apply the vendor's patch. ## Is CVE-2024-49875 being exploited? There is no known exploitation of CVE-2024-49875 in the wild and no public exploit code. ## Other vulnerabilities in Linux kernel - [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild) - [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild) - [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild) - [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild) - [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2024-49875 and fix it if it is affected. What it is: CVE-2024-49875 is a high-severity denial of service vulnerability in Linux kernel, published on 21 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2024-49875 in the wild and no public exploit code. Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2024-49875/ (Markdown: https://insights.sbomify.com/CVE-2024-49875/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-49875 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-49875 - OSV: https://osv.dev/vulnerability/CVE-2024-49875 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-49875/ Summaries are generated and may contain mistakes; the official description above is the record.