CVE-2024-26631

Published Mar 18, 2024

Last updated a year ago

CVSS medium 4.7

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: fix data-race in ipv6_mc_down / mld_ifc_work idev->mc_ifc_count can be written over without proper locking. Originally found by syzbot [1], fix this issue by encapsulating calls to mld_ifc_stop_work() (and mld_gq_stop_work() for good measure) with mutex_lock() and mutex_unlock() accordingly as these functions should only be called with mc_lock per their declarations. [1] BUG: KCSAN: data-race in ipv6_mc_down / mld_ifc_work write to 0xffff88813a80c832 of 1 bytes by task 3771 on cpu 0: mld_ifc_stop_work net/ipv6/mcast.c:1080 [inline] ipv6_mc_down+0x10a/0x280 net/ipv6/mcast.c:2725 addrconf_ifdown+0xe32/0xf10 net/ipv6/addrconf.c:3949 addrconf_notify+0x310/0x980 notifier_call_chain kernel/notifier.c:93 [inline] raw_notifier_call_chain+0x6b/0x1c0 kernel/notifier.c:461 __dev_notify_flags+0x205/0x3d0 dev_change_flags+0xab/0xd0 net/core/dev.c:8685 do_setlink+0x9f6/0x2430 net/core/rtnetlink.c:2916 rtnl_group_changelink net/core/rtnetlink.c:3458 [inline] __rtnl_newlink net/core/rtnetlink.c:3717 [inline] rtnl_newlink+0xbb3/0x1670 net/core/rtnetlink.c:3754 rtnetlink_rcv_msg+0x807/0x8c0 net/core/rtnetlink.c:6558 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2545 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6576 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0x589/0x650 net/netlink/af_netlink.c:1368 netlink_sendmsg+0x66e/0x770 net/netlink/af_netlink.c:1910 ... write to 0xffff88813a80c832 of 1 bytes by task 22 on cpu 1: mld_ifc_work+0x54c/0x7b0 net/ipv6/mcast.c:2653 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2700 worker_thread+0x525/0x730 kernel/workqueue.c:2781 ...
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
4.7
Impact score
3.6
Exploitability score
1
Vector string
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
CWE-667

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. In the Linux kernel, the following vulnerability has been resolved: romfs: check sb_set_blocksize() return value romfs_fill_super() ignores the return value of sb_set_blocksize(), which can fail if the requested block size is incompatible with the block device's configuration. This can be triggered by setting a loop device's block size larger than PAGE_SIZE using ioctl(LOOP_SET_BLOCK_SIZE, 32768), then mounting a romfs filesystem on that device. When sb_set_blocksize(sb, ROMBSIZE) is called with ROMBSIZE=4096 but the device has logical_block_size=32768, bdev_validate_blocksize() fails because the requested size is smaller than the device's logical block size. sb_set_blocksize() returns 0 (failure), but romfs ignores this and continues mounting. The superblock's block size remains at the device's logical block size (32768). Later, when sb_bread() attempts I/O with this oversized block size, it triggers a kernel BUG in folio_set_bh(): kernel BUG at fs/buffer.c:1582! BUG_ON(size > PAGE_SIZE); Fix by checking the return value of sb_set_blocksize() and failing the mount with -EINVAL if it returns 0.•CVE-2026-23238
  2. In the Linux kernel, the following vulnerability has been resolved: platform/x86: classmate-laptop: Add missing NULL pointer checks In a few places in the Classmate laptop driver, code using the accel object may run before that object's address is stored in the driver data of the input device using it. For example, cmpc_accel_sensitivity_store_v4() is the "show" method of cmpc_accel_sensitivity_attr_v4 which is added in cmpc_accel_add_v4(), before calling dev_set_drvdata() for inputdev->dev. If the sysfs attribute is accessed prematurely, the dev_get_drvdata(&inputdev->dev) call in in cmpc_accel_sensitivity_store_v4() returns NULL which leads to a NULL pointer dereference going forward. Moreover, sysfs attributes using the input device are added before initializing that device by cmpc_add_acpi_notify_device() and if one of them is accessed before running that function, a NULL pointer dereference will occur. For example, cmpc_accel_sensitivity_attr_v4 is added before calling cmpc_add_acpi_notify_device() and if it is read prematurely, the dev_get_drvdata(&acpi->dev) call in cmpc_accel_sensitivity_show_v4() returns NULL which leads to a NULL pointer dereference going forward. Fix this by adding NULL pointer checks in all of the relevant places.•CVE-2026-23237
  3. In the Linux kernel, the following vulnerability has been resolved: fbdev: smscufx: properly copy ioctl memory to kernelspace The UFX_IOCTL_REPORT_DAMAGE ioctl does not properly copy data from userspace to kernelspace, and instead directly references the memory, which can cause problems if invalid data is passed from userspace. Fix this all up by correctly copying the memory before accessing it within the kernel.•CVE-2026-23236
  4. In the Linux kernel, the following vulnerability has been resolved: f2fs: fix out-of-bounds access in sysfs attribute read/write Some f2fs sysfs attributes suffer from out-of-bounds memory access and incorrect handling of integer values whose size is not 4 bytes. For example: vm:~# echo 65537 > /sys/fs/f2fs/vde/carve_out vm:~# cat /sys/fs/f2fs/vde/carve_out 65537 vm:~# echo 4294967297 > /sys/fs/f2fs/vde/atgc_age_threshold vm:~# cat /sys/fs/f2fs/vde/atgc_age_threshold 1 carve_out maps to {struct f2fs_sb_info}->carve_out, which is a 8-bit integer. However, the sysfs interface allows setting it to a value larger than 255, resulting in an out-of-range update. atgc_age_threshold maps to {struct atgc_management}->age_threshold, which is a 64-bit integer, but its sysfs interface cannot correctly set values larger than UINT_MAX. The root causes are: 1. __sbi_store() treats all default values as unsigned int, which prevents updating integers larger than 4 bytes and causes out-of-bounds writes for integers smaller than 4 bytes. 2. f2fs_sbi_show() also assumes all default values are unsigned int, leading to out-of-bounds reads and incorrect access to integers larger than 4 bytes. This patch introduces {struct f2fs_attr}->size to record the actual size of the integer associated with each sysfs attribute. With this information, sysfs read and write operations can correctly access and update values according to their real data size, avoiding memory corruption and truncation.•CVE-2026-23235
  5. In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid UAF in f2fs_write_end_io() As syzbot reported an use-after-free issue in f2fs_write_end_io(). It is caused by below race condition: loop device umount - worker_thread - loop_process_work - do_req_filebacked - lo_rw_aio - lo_rw_aio_complete - blk_mq_end_request - blk_update_request - f2fs_write_end_io - dec_page_count - folio_end_writeback - kill_f2fs_super - kill_block_super - f2fs_put_super : free(sbi) : get_pages(, F2FS_WB_CP_DATA) accessed sbi which is freed In kill_f2fs_super(), we will drop all page caches of f2fs inodes before call free(sbi), it guarantee that all folios should end its writeback, so it should be safe to access sbi before last folio_end_writeback(). Let's relocate ckpt thread wakeup flow before folio_end_writeback() to resolve this issue.•CVE-2026-23234

References

Sources include official advisories and independent security research.