high CVSS 7.1

CVE-2022-48827·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: NFSD: Fix the behavior of READ near OFFSET_MAX Dan Aloni reports: > Due to commit 8cfb9015280d ("NFS: Always provide aligned buffers to > the RPC read layers") on the client, a read of 0xfff is aligned up > to server rsize of 0x1000. > > As a result, in a test where the server has a file of size > 0x7fffffffffffffff, and the client tries to read from the offset > 0x7ffffffffffff000, the read causes loff_t overflow in the server > and it returns an NFS code of EINVAL to the client. The client as > a result indefinitely retries the request. The Linux NFS client does not handle NFS?ERR_INVAL, even though all NFS specifications permit servers to return that status code for a READ. Instead of NFS?ERR_INVAL, have out-of-range READ requests succeed and return a short result. Set the EOF flag in the result to prevent the client from retrying the READ request. This behavior appears to be consistent with Solaris NFS servers. Note that NFSv3 and NFSv4 use u64 offset values on the wire. These must be converted to loff_t internally before use -- an implicit type cast is not adequate for this purpose. Otherwise VFS checks against sb->s_maxbytes do not work properly.

Severity
high
Software
Kernel
Fixed in
5.16.10
Published
2024-07-16

Affected versions

From: 5.16

Until: 5.16.10

Fixed in: 5.16.10

How to fix this CVE

Update your Linux kernel to version 5.16.10 or later to resolve an NFS READ operation vulnerability that can cause integer overflow when accessing files near the maximum offset limit. This fix ensures that out-of-range READ requests return appropriate responses with EOF flags instead of causing server errors and client retry loops. Apply the patch immediately if you are running NFSD with NFS clients that perform large read operations.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check your current kernel version: uname -r
  2. Verify if you are running a vulnerable version (5.16 to 5.16.9): if your kernel version falls in this range, your system is vulnerable
  3. Confirm NFSD is enabled: systemctl status nfs-server or ps aux | grep nfsd
  4. Review kernel logs for NFS READ errors near large offsets: dmesg | grep -i 'nfs.*read' or journalctl -u nfs-server | grep -i 'overflow'
  5. Verify the patch is applied by checking kernel release: uname -r should show 5.16.10 or later

FAQ

What is CVE-2022-48827?

This vulnerability affects the Linux kernel's NFS server implementation, specifically in how it handles READ operations targeting file offsets near the maximum representable value. An integer overflow condition can cause the server to return EINVAL errors instead of handling the request gracefully, triggering infinite client retries.

Is CVE-2022-48827 being actively exploited?

No, this vulnerability is not listed on the CISA Known Exploited Vulnerabilities catalog and has no publicly available exploits. It requires specific NFS client and server configurations to trigger.

What versions of Kernel are affected by CVE-2022-48827?

Linux kernel versions 5.16 through 5.16.9 are affected. Version 5.16.10 and all later versions include the fix.

How do I check if my server is vulnerable to CVE-2022-48827?

Run 'uname -r' to check your kernel version. If it shows 5.16.0 through 5.16.9, your system is vulnerable. Additionally, verify NFSD is running with 'systemctl status nfs-server'.

Does Defensia detect CVE-2022-48827?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server, CVE-2022-48827 will appear in your dashboard with remediation steps.

Related Kernel CVEs

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CVE-2026-64035CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: igc: set tx buffer type for SMD frames Sashiko pointed out that igc_fpe_init_smd_frame() initializes igc_tx_buffer fields for an SMD skb, but does not set the buffer type: https://sashiko.dev/#/patchset/20260415025226.114115-1-kohei%40enjuk.jp Since igc_tx_buffer entries are reused, a stale XDP or XSK type can remain and make TX completion use the wrong cleanup path. Set the buffer type to IGC_TX_BUFFER_TYPE_SKB.
CVE-2026-64033CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: RDMA/rtrs: Fix use-after-free in path file creation cleanup In the error path of rtrs_srv_create_path_files(), the sysfs root folders may already have been created and srv_path->kobj may already have been initialized. If a later step fails, the cleanup currently calls kobject_put(&srv_path->kobj) before rtrs_srv_destroy_once_sysfs_root_folders(srv_path). kobject_put() may drop the last reference to srv_path->kobj and invoke the release callback, rtrs_srv_release(), which frees srv_path. The following call to rtrs_srv_destroy_once_sysfs_root_folders(srv_path) then dereferences srv_path internally to access srv_path->srv, resulting in a use-after-free. This failure path is reached before rtrs_srv_create_path_files() returns success, so the successful-path lifetime handling is not involved. Fix this by destroying the sysfs root folders before calling kobject_put(&srv_path->kobj), so srv_path is still valid while the helper accesses it. This issue was found by a static analysis tool I am developing.
CVE-2026-64037CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mld: fix TSO segmentation explosion when AMSDU is disabled When the TLC notification disables AMSDU for a TID, the MLD driver sets max_tid_amsdu_len to the sentinel value 1. The TSO segmentation path in iwl_mld_tx_tso_segment() checks for zero but not for this sentinel, allowing it to reach the num_subframes calculation: num_subframes = (max_tid_amsdu_len + pad) / (subf_len + pad) = (1 + 2) / (1534 + 2) = 0 This zero propagates to iwl_tx_tso_segment() which sets: gso_size = num_subframes * mss = 0 Calling skb_gso_segment() with gso_size=0 creates over 32000 tiny segments from a single GSO skb. This floods the TX ring with ~1024 micro-frames (the rest are purged), creating a massive burst of TX completion events that can lead to memory corruption and a subsequent use-after-free in TCP's retransmit queue (refcount underflow in tcp_shifted_skb, NULL deref in tcp_rack_detect_loss). The MVM driver is immune because it checks mvmsta->amsdu_enabled before reaching the num_subframes calculation. The MLD driver has no equivalent bitmap check and relies solely on max_tid_amsdu_len, which does not catch the sentinel value. Fix this by detecting the sentinel value (max_tid_amsdu_len == 1) at the existing check and falling back to non-AMSDU TSO segmentation. Also add a WARN_ON_ONCE guard after the num_subframes division as defense-in-depth to catch any future code paths that produce zero through a different mechanism.
CVE-2026-64000CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: net: hsr: fix potential OOB access in supervision frame handling Ensure the entire TLV header is linearized before access by adding sizeof(struct hsr_sup_tlv) to the pskb_may_pull() calls. Without this, a truncated frame could cause an out-of-bounds access.

References

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