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
…
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"net/ipv6/mcast.c"
],
"versions": [
{
"version": "2d9a93b4902b",
"lessThan": "62b3387beef1",
"status": "affected",
"versionType": "git"
},
{
"version": "2d9a93b4902b",
"lessThan": "380540bb06bb",
"status": "affected",
"versionType": "git"
},
{
"version": "2d9a93b4902b",
"lessThan": "3cc283fd16fb",
"status": "affected",
"versionType": "git"
},
{
"version": "2d9a93b4902b",
"lessThan": "3bb5849675ae",
"status": "affected",
"versionType": "git"
},
{
"version": "2d9a93b4902b",
"lessThan": "2e7ef287f07c",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"net/ipv6/mcast.c"
],
"versions": [
{
"version": "5.13",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.13",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.15.148",
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.1.75",
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.6.14",
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.7.2",
"lessThanOrEqual": "6.7.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.8",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]
git.kernel.org/stable/c/2e7ef287f07c74985f1bf2858bedc62bd9ebf155
git.kernel.org/stable/c/380540bb06bb1d1b12bdc947d1b8f56cda6b5663
git.kernel.org/stable/c/3bb5849675ae1d592929798a2b37ea450879c855
git.kernel.org/stable/c/3cc283fd16fba72e2cefe3a6f48d7a36b0438900
git.kernel.org/stable/c/62b3387beef11738eb6ce667601a28fa089fa02c