{"id":"CVE-2024-26631","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: mcast: fix data-race in ipv6_mc_down / mld_ifc_work\n\nidev->mc_ifc_count can be written over without proper locking.\n\nOriginally found by syzbot [1], fix this issu…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: mcast: fix data-race in ipv6_mc_down / mld_ifc_work\n\nidev->mc_ifc_count can be written over without proper locking.\n\nOriginally found by syzbot [1], fix this issu…","severity":"medium","cvss":4.7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-667"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.13, < 5.15.148","linux_kernel >= 5.16, < 6.1.75","linux_kernel >= 6.2, < 6.6.14","linux_kernel >= 6.7, < 6.7.2"],"patched":["linux_kernel 6.7.2"],"published":"2024-03-18","updated":"2026-07-24","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2024-26631","references":[{"url":"https://git.kernel.org/stable/c/2e7ef287f07c74985f1bf2858bedc62bd9ebf155","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/380540bb06bb1d1b12bdc947d1b8f56cda6b5663","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3bb5849675ae1d592929798a2b37ea450879c855","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3cc283fd16fba72e2cefe3a6f48d7a36b0438900","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/62b3387beef11738eb6ce667601a28fa089fa02c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/75ddcd741d2a30696f5893bc71a9d28f4ef22311","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2e7ef287f07c74985f1bf2858bedc62bd9ebf155","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/380540bb06bb1d1b12bdc947d1b8f56cda6b5663","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/3bb5849675ae1d592929798a2b37ea450879c855","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/3cc283fd16fba72e2cefe3a6f48d7a36b0438900","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/62b3387beef11738eb6ce667601a28fa089fa02c","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd"],"epss":0.00186,"epssPercentile":0.08478,"ingestedAt":"2026-07-24T15:30:57.240Z","slug":"CVE-2024-26631","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nipv6: mcast: fix data-race in ipv6_mc_down / mld_ifc_work\n\nidev->mc_ifc_count can be written over without proper locking.\n\nOriginally found by syzbot [1], fix this issue by encapsulating calls\nto mld_ifc_stop_work() (and mld_gq_stop_work() for good measure) with\nmutex_lock() and mutex_unlock() accordingly as these functions\nshould only be called with mc_lock per their declarations.\n\n[1]\nBUG: KCSAN: data-race in ipv6_mc_down / mld_ifc_work\n\nwrite to 0xffff88813a80c832 of 1 bytes by task 3771 on cpu 0:\n mld_ifc_stop_work net/ipv6/mcast.c:1080 [inline]\n ipv6_mc_down+0x10a/0x280 net/ipv6/mcast.c:2725\n addrconf_ifdown+0xe32/0xf10 net/ipv6/addrconf.c:3949\n addrconf_notify+0x310/0x980\n notifier_call_chain kernel/notifier.c:93 [inline]\n raw_notifier_call_chain+0x6b/0x1c0 kernel/notifier.c:461\n __dev_notify_flags+0x205/0x3d0\n dev_change_flags+0xab/0xd0 net/core/dev.c:8685\n do_setlink+0x9f6/0x2430 net/core/rtnetlink.c:2916\n rtnl_group_changelink net/core/rtnetlink.c:3458 [inline]\n __rtnl_newlink net/core/rtnetlink.c:3717 [inline]\n rtnl_newlink+0xbb3/0x1670 net/core/rtnetlink.c:3754\n rtnetlink_rcv_msg+0x807/0x8c0 net/core/rtnetlink.c:6558\n netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2545\n rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6576\n netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]\n netlink_unicast+0x589/0x650 net/netlink/af_netlink.c:1368\n netlink_sendmsg+0x66e/0x770 net/netlink/af_netlink.c:1910\n ...\n\nwrite to 0xffff88813a80c832 of 1 bytes by task 22 on cpu 1:\n mld_ifc_work+0x54c/0x7b0 net/ipv6/mcast.c:2653\n process_one_work kernel/workqueue.c:2627 [inline]\n process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2700\n worker_thread+0x525/0x730 kernel/workqueue.c:2781\n ...\n\n## Affected\n\n- `linux_kernel >= 5.13, < 5.15.148`\n- `linux_kernel >= 5.16, < 6.1.75`\n- `linux_kernel >= 6.2, < 6.6.14`\n- `linux_kernel >= 6.7, < 6.7.2`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.7.2`","depth":"sunlit","depthScore":26,"depthScoreParts":{"impact":25.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}