CVE-2026-93226
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: use RCU iterator to dump route exceptions rt6_nh_dump_exceptions() uses hlist_for_each_entry() to iterate over RCU-protected exception lists. The caller holds rcu_read_lock(), but does not hold rt6_exception_lock, so rt6_insert_exception() can concurrently add an entry with hlist_add_head_rcu(). KCSAN reports this race (irrelevant details omitted): ================================================================== BUG: KCSAN: data-race in rt6_insert_exception / rt6_nh_dump_exceptions write (marked) to 0xffff8a7c44c59620 of 8 bytes by interrupt on cpu 5: rt6_insert_exception+0x3bb/0x760 __ip6_rt_update_pmtu+0x4fe/0x750 ip6_sk_update_pmtu+0x19a/0x3b0 udpv6_err+0x3ff/0x800 icmpv6_notify+0x1e1/0x440 icmpv6_rcv+0x8c0/0xab0 ip6_protocol_deliver_rcu+0x616/0x840 ip6_input_finish+0xb9/0x160 ... entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff8a7c44c59620 of 8 bytes by task 549 on cpu 14: rt6_nh_dump_exceptions+0xb3/0x260 rt6_dump_route+0x53e/0x5f0 fib6_dump_node+0x6d/0xf0 fib6_walk_continue+0x290/0x2d0 fib6_dump_table+0x28d/0x360 inet6_dump_fib+0x37d/0x620 rtnl_dumpit+0x7b/0xd0 netlink_dump+0x3ae/0x7e0 ... entry_SYSCALL_64_after_hwframe+0x77/0x7f 4 locks held by dumper/549: ... #1: (rcu_read_lock){....}-{1:3}, at: inet6_dump_fib+0x88/0x620 #2: (&tb->tb6_lock){+.-.}-{3:3}, at: fib6_dump_table+0x1e9/0x360 #3: (rcu_read_lock){....}-{1:3}, at: rt6_dump_route+0x483/0x5f0 value changed: 0xffff8a7c44e05700 -> 0xffff8a7c45d60100 Reported by Kernel Concurrency Sanitizer on: CPU: 14 UID: 0 PID: 549 Comm: dumper Not tainted 7.2.0-rc7-virtme #38 PREEMPT(lazy) ... Use hlist_for_each_entry_rcu() to safely iterate over the exception list.
View original CVE JSON
{
"id": "CVE-2026-93226",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-24T16:17:17.973",
"lastModified": "2026-10-19T10:17:13.610",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: use RCU iterator to dump route exceptions\n\nrt6_nh_dump_exceptions() uses hlist_for_each_entry() to iterate over\nRCU-protected exception lists. The caller holds rcu_read_lock(), but does\nnot hold rt6_exception_lock, so rt6_insert_exception() can concurrently\nadd an entry with hlist_add_head_rcu().\n\nKCSAN reports this race (irrelevant details omitted):\n\n ==================================================================\n BUG: KCSAN: data-race in rt6_insert_exception / rt6_nh_dump_exceptions\n\n write (marked) to 0xffff8a7c44c59620 of 8 bytes by interrupt on cpu 5:\n rt6_insert_exception+0x3bb/0x760\n __ip6_rt_update_pmtu+0x4fe/0x750\n ip6_sk_update_pmtu+0x19a/0x3b0\n udpv6_err+0x3ff/0x800\n icmpv6_notify+0x1e1/0x440\n icmpv6_rcv+0x8c0/0xab0\n ip6_protocol_deliver_rcu+0x616/0x840\n ip6_input_finish+0xb9/0x160\n ...\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n read to 0xffff8a7c44c59620 of 8 bytes by task 549 on cpu 14:\n rt6_nh_dump_exceptions+0xb3/0x260\n rt6_dump_route+0x53e/0x5f0\n fib6_dump_node+0x6d/0xf0\n fib6_walk_continue+0x290/0x2d0\n fib6_dump_table+0x28d/0x360\n inet6_dump_fib+0x37d/0x620\n rtnl_dumpit+0x7b/0xd0\n netlink_dump+0x3ae/0x7e0\n ...\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n 4 locks held by dumper/549:\n ...\n #1: (rcu_read_lock){....}-{1:3}, at: inet6_dump_fib+0x88/0x620\n #2: (&tb->tb6_lock){+.-.}-{3:3}, at: fib6_dump_table+0x1e9/0x360\n #3: (rcu_read_lock){....}-{1:3}, at: rt6_dump_route+0x483/0x5f0\n\n value changed: 0xffff8a7c44e05700 -> 0xffff8a7c45d60100\n\n Reported by Kernel Concurrency Sanitizer on:\n CPU: 14 UID: 0 PID: 549 Comm: dumper Not tainted\n 7.2.0-rc7-virtme #38 PREEMPT(lazy)\n ...\n\nUse hlist_for_each_entry_rcu() to safely iterate over the exception list."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/ipv6/route.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9",
"lessThan": "dffbfb3117138e8e0e09d05f507bd36ca1f696e5",
"versionType": "git",
"status": "affected"
},
{
"version": "1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9",
"lessThan": "6bd3f94ed858f2d072627546b4cdf712b0f8ea88",
"versionType": "git",
"status": "affected"
},
{
"version": "1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9",
"lessThan": "9c6be625e1a7258e845d6193b3b6b084a00f8e9e",
"versionType": "git",
"status": "affected"
},
{
"version": "1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9",
"lessThan": "3665abc3d2ae8a78cb67f858e848481432ec75db",
"versionType": "git",
"status": "affected"
},
{
"version": "1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9",
"lessThan": "eda56ee17713f9dd834b922f7dbfa2e25fa6358c",
"versionType": "git",
"status": "affected"
},
{
"version": "1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9",
"lessThan": "a602cd128d17a793e12888edc8eda85821ede7e1",
"versionType": "git",
"status": "affected"
},
{
"version": "1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9",
"lessThan": "f6b1b15848fd91fe122dac0d19d3d666e35075b6",
"versionType": "git",
"status": "affected"
},
{
"version": "1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9",
"lessThan": "47cdab0d51aaa9bd85f8e4904585bd5bd4df4488",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/ipv6/route.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.3",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.3",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.270",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.221",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.188",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.157",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.109",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.50",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.4",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/3665abc3d2ae8a78cb67f858e848481432ec75db",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/47cdab0d51aaa9bd85f8e4904585bd5bd4df4488",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6bd3f94ed858f2d072627546b4cdf712b0f8ea88",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9c6be625e1a7258e845d6193b3b6b084a00f8e9e",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a602cd128d17a793e12888edc8eda85821ede7e1",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/dffbfb3117138e8e0e09d05f507bd36ca1f696e5",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/eda56ee17713f9dd834b922f7dbfa2e25fa6358c",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f6b1b15848fd91fe122dac0d19d3d666e35075b6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}