CVE-2024-26831

Published Apr 17, 2024

Last updated a year ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: net/handshake: Fix handshake_req_destroy_test1 Recently, handshake_req_destroy_test1 started failing: Expected handshake_req_destroy_test == req, but handshake_req_destroy_test == 0000000000000000 req == 0000000060f99b40 not ok 11 req_destroy works This is because "sock_release(sock)" was replaced with "fput(filp)" to address a memory leak. Note that sock_release() is synchronous but fput() usually delays the final close and clean-up. The delay is not consequential in the other cases that were changed but handshake_req_destroy_test1 is testing that handshake_req_cancel() followed by closing the file actually does call the ->hp_destroy method. Thus the PTR_EQ test at the end has to be sure that the final close is complete before it checks the pointer. We cannot use a completion here because if ->hp_destroy is never called (ie, there is an API bug) then the test will hang. Reported by: Guenter Roeck <linux@roeck-us.net>
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
CWE-401

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: ipv6: account for fraggap on the paged allocation path In __ip6_append_data(), when the paged-allocation branch is taken (MSG_MORE / NETIF_F_SG / large fraglen), alloclen and pagedlen are computed as alloclen = fragheaderlen + transhdrlen; pagedlen = datalen - transhdrlen; datalen already includes fraggap (datalen = length + fraggap). When fraggap is non-zero, this is not the first skb and transhdrlen is zero. The fraggap bytes carried over from the previous skb are copied just past the fragment headers in the new skb's linear area. The linear area is therefore undersized by fraggap bytes while pagedlen is overstated by the same amount, and the copy writes past skb->end into the trailing skb_shared_info. An unprivileged user can trigger this via a UDPv6 socket using MSG_MORE together with MSG_SPLICE_PAGES. The bad accounting was introduced by commit 773ba4fe9104 ("ipv6: avoid partial copy for zc"). Before commit ce650a166335 ("udp6: Fix __ip6_append_data()'s handling of MSG_SPLICE_PAGES"), the negative copy value caused -EINVAL to be returned. That later commit allowed MSG_SPLICE_PAGES to proceed in this case, making the corruption triggerable. The non-paged branch sets alloclen to fraglen, which already accounts for fraggap because datalen does. Bring the paged branch in line by adding fraggap to alloclen and subtracting it from pagedlen. After this adjustment, copy no longer collapses to -fraggap on the paged path, so remove the stale comment describing that old arithmetic. Since a negative copy is no longer expected for a valid MSG_SPLICE_PAGES case, remove the MSG_SPLICE_PAGES exception from the negative copy check.CVE-2026-53362