UBUNTU-CVE-2026-93226: Medium severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: ipv6: use RCU iterator to dump route exceptions rt6nhdumpexceptions() uses hlistforeachentry() to iterate over RCU-protected exception lists. The caller holds rcureadlock(), but does not hold rt6exceptionlock, so rt6insertexception() can concurrently add an entry with hlistaddheadrcu(). KCSAN reports this race (irrelevant details omitted): ================================================================== BUG: KCSAN: data-race in rt6insertexception / rt6nhdumpexceptions write (marked) to 0xffff8a7c44c59620 of 8 bytes by interrupt on cpu 5: rt6insertexception+0x3bb/0x760 ip6rtupdatepmtu+0x4fe/0x750 ip6skupdatepmtu+0x19a/0x3b0 udpv6err+0x3ff/0x800 icmpv6notify+0x1e1/0x440 icmpv6rcv+0x8c0/0xab0 ip6protocoldeliverrcu+0x616/0x840 ip6inputfinish+0xb9/0x160 ... entrySYSCALL64afterhwframe+0x77/0x7f read to 0xffff8a7c44c59620 of 8 bytes by task 549 on cpu 14: rt6nhdumpexceptions+0xb3/0x260 rt6dumproute+0x53e/0x5f0 fib6dumpnode+0x6d/0xf0 fib6walkcontinue+0x290/0x2d0 fib6dumptable+0x28d/0x360 inet6dumpfib+0x37d/0x620 rtnldumpit+0x7b/0xd0 netlinkdump+0x3ae/0x7e0 ... entrySYSCALL64afterhwframe+0x77/0x7f 4 locks held by dumper/549: ... #1: (rcureadlock){....}-{1:3}, at: inet6dumpfib+0x88/0x620 #2: (&tb->tb6lock){+.-.}-{3:3}, at: fib6dumptable+0x1e9/0x360 #3: (rcureadlock){....}-{1:3}, at: rt6dumproute+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 hlistforeachentryrcu() to safely iterate over the exception list.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
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ubuntu/linux-aws-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1119.126~20.04.1 - Upgrade
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ubuntu/linux-azure-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1125.134~20.04.1 - Upgrade
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ubuntu/linux-azure-fde-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1124.133~20.04.1 - Upgrade
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ubuntu/linux-gcp-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1120.130~20.04.1 - Upgrade
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ubuntu/linux-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-202.212~20.04.1 - Upgrade
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ubuntu/linux-ibm-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1113.117~20.04.1 - Upgrade
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ubuntu/linux-intel-iotg-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1114.120~20.04.1 - Upgrade
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ubuntu/linux-lowlatency-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-197.207~20.04.1 - Upgrade
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ubuntu/linux-nvidia-tegra-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1070.72~20.04.1 - Upgrade
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ubuntu/linux-oracle-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1116.122~20.04.1 - Upgrade
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ubuntu/linux-riscv-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1113.117~20.04.2 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 5.15.0-202.212 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 5.15.0-1119.126 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 5.15.0-1125.134 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 5.15.0-1124.133 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 5.15.0-1120.130 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 5.15.0-1115.121 - Upgrade
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ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 5.15.0-1102.110 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 5.15.0-1113.117 - Upgrade
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ubuntu/linux-intel-iotgto a version that resolves this vulnerability.Fixed in 5.15.0-1114.120 - Upgrade
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ubuntu/linux-kvmto a version that resolves this vulnerability.Fixed in 5.15.0-1111.116 - Upgrade
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ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 5.15.0-197.207 - Upgrade
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ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 5.15.0-1114.115 - Upgrade
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ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 5.15.0-1070.72 - Upgrade
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ubuntu/linux-nvidia-tegra-igxto a version that resolves this vulnerability.Fixed in 5.15.0-1059.59 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 5.15.0-1116.122 - Upgrade
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ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 5.15.0-1103.105 - Upgrade
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ubuntu/linux-intel-iot-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1111.115 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1118.127 - Upgrade
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ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1119.126+fips1 - Upgrade
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ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1125.134+fips1 - Upgrade
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ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-202.212+fips1 - Upgrade
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ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1120.130+fips1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1