{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-49872","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-05-01T14:05:17.238Z","datePublished":"2025-05-01T14:10:22.402Z","dateUpdated":"2026-08-05T08:56:29.682Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T08:56:29.682Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: gso: fix panic on frag_list with mixed head alloc types\n\nSince commit 3dcbdb134f32 (\"net: gso: Fix skb_segment splat when\nsplitting gso_size mangled skb having linear-headed frag_list\"), it is\nallowed to change gso_size of a GRO packet. However, that commit assumes\nthat \"checking the first list_skb member suffices; i.e if either of the\nlist_skb members have non head_frag head, then the first one has too\".\n\nIt turns out this assumption does not hold. We've seen BUG_ON being hit\nin skb_segment when skbs on the frag_list had differing head_frag with\nthe vmxnet3 driver. This happens because __netdev_alloc_skb and\n__napi_alloc_skb can return a skb that is page backed or kmalloced\ndepending on the requested size. As the result, the last small skb in\nthe GRO packet can be kmalloced.\n\nThere are three different locations where this can be fixed:\n\n(1) We could check head_frag in GRO and not allow GROing skbs with\n    different head_frag. However, that would lead to performance\n    regression on normal forward paths with unmodified gso_size, where\n    !head_frag in the last packet is not a problem.\n\n(2) Set a flag in bpf_skb_net_grow and bpf_skb_net_shrink indicating\n    that NETIF_F_SG is undesirable. That would need to eat a bit in\n    sk_buff. Furthermore, that flag can be unset when all skbs on the\n    frag_list are page backed. To retain good performance,\n    bpf_skb_net_grow/shrink would have to walk the frag_list.\n\n(3) Walk the frag_list in skb_segment when determining whether\n    NETIF_F_SG should be cleared. This of course slows things down.\n\nThis patch implements (3). To limit the performance impact in\nskb_segment, the list is walked only for skbs with SKB_GSO_DODGY set\nthat have gso_size changed. Normal paths thus will not hit it.\n\nWe could check only the last skb but since we need to walk the whole\nlist anyway, let's stay on the safe side."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - GRO builds the fragile frag_list skb from remote TCP/UDP packets on ingress; with a realistic TC/LWT BPF NAT64 or adjust_room datapath (the path this bug was fixed for, and observed with vmxnet3), egress skb_segment runs on those packets, so an unauthenticated remote peer triggers the panic by sending traffic through the gateway.\nAC:L - The attacker controls segment sizes so GRO’s last member is small enough to be kmalloced (!head_frag) while earlier members are page-backed, and once SKB_GSO_DODGY is set by the in-path BPF helper the incomplete first-only check fails and BUG_ON fires deterministically—no race or uncontrollable memory layout.\nPR:N - In the highest-impact deployment the administrator has already attached the BPF/NAT datapath; the attacker needs no host account or capability and only sends unauthenticated packets on the wire.\nUI:N - Packet reception, GRO, BPF gso_size mangling, and egress GSO segmentation all run automatically in softirq on an up interface with no separate victim action.\nS:U - The BUG_ON/oops/panic is confined to the host kernel processing the packets and does not cross a VM, IOMMU, or other security-authority boundary.\nC:N - The failure is an intentional BUG_ON(!list_skb->head_frag) in skb_segment before any page-desc conversion or data copy from the bad head, so there is no OOB read or info-disclosure primitive.\nI:N - The assertion aborts before skb_head_frag_to_page_desc would treat a kmalloc head as a page fragment, so there is no OOB/UAF write or control-flow hijack primitive—only the panic.\nA:H - Hitting BUG_ON in skb_segment from the NAPI/softirq GSO path oopses/panics the host (as reported with vmxnet3), and it can be re-triggered by resending traffic—full availability impact."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/skbuff.c"],"versions":[{"version":"162a5a8c3aff15c449e6b38355cdf80ab4f77a5a","lessThan":"5876b7f249a1ecbbcc8e35072c3828d6526d1c3a","status":"affected","versionType":"git"},{"version":"55fb612bef7fd237fb70068e2b6ff1cd1543a8ef","lessThan":"0a9f56e525ea871d3950b90076912f5c7494f00f","status":"affected","versionType":"git"},{"version":"821302dd0c51d29269ef73a595bdff294419e2cd","lessThan":"bd5362e58721e4d0d1a37796593bd6e51536ce7a","status":"affected","versionType":"git"},{"version":"3dcbdb134f329842a38f0e6797191b885ab00a00","lessThan":"65ad047fd83502447269fda8fd26c99077a9af47","status":"affected","versionType":"git"},{"version":"3dcbdb134f329842a38f0e6797191b885ab00a00","lessThan":"50868de7dc4e7f0fcadd6029f32bf4387c102ee6","status":"affected","versionType":"git"},{"version":"3dcbdb134f329842a38f0e6797191b885ab00a00","lessThan":"ad25a115f50800c6847e0d841c5c7992a9f7c1b3","status":"affected","versionType":"git"},{"version":"3dcbdb134f329842a38f0e6797191b885ab00a00","lessThan":"598d9e30927b15731e83797fbd700ecf399f42dd","status":"affected","versionType":"git"},{"version":"3dcbdb134f329842a38f0e6797191b885ab00a00","lessThan":"9e4b7a99a03aefd37ba7bb1f022c8efab5019165","status":"affected","versionType":"git"},{"version":"92984818ff8cfd97311a5e0ac27f148a00df2b54","status":"affected","versionType":"git"},{"version":"4.9.194","lessThan":"4.9.334","status":"affected","versionType":"semver"},{"version":"4.14.145","lessThan":"4.14.300","status":"affected","versionType":"semver"},{"version":"4.19.74","lessThan":"4.19.267","status":"affected","versionType":"semver"},{"version":"5.2.16","lessThan":"5.3","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/skbuff.c"],"versions":[{"version":"5.3","status":"affected"},{"version":"0","lessThan":"5.3","status":"unaffected","versionType":"semver"},{"version":"4.9.334","lessThanOrEqual":"4.9.*","status":"unaffected","versionType":"semver"},{"version":"4.14.300","lessThanOrEqual":"4.14.*","status":"unaffected","versionType":"semver"},{"version":"4.19.267","lessThanOrEqual":"4.19.*","status":"unaffected","versionType":"semver"},{"version":"5.4.225","lessThanOrEqual":"5.4.*","status":"unaffected","versionType":"semver"},{"version":"5.10.155","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.79","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.0.9","lessThanOrEqual":"6.0.*","status":"unaffected","versionType":"semver"},{"version":"6.1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9.194","versionEndExcluding":"4.9.334"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14.145","versionEndExcluding":"4.14.300"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19.74","versionEndExcluding":"4.19.267"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"5.4.225"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"5.10.155"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"5.15.79"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.0.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.2.16"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/5876b7f249a1ecbbcc8e35072c3828d6526d1c3a"},{"url":"https://git.kernel.org/stable/c/0a9f56e525ea871d3950b90076912f5c7494f00f"},{"url":"https://git.kernel.org/stable/c/bd5362e58721e4d0d1a37796593bd6e51536ce7a"},{"url":"https://git.kernel.org/stable/c/65ad047fd83502447269fda8fd26c99077a9af47"},{"url":"https://git.kernel.org/stable/c/50868de7dc4e7f0fcadd6029f32bf4387c102ee6"},{"url":"https://git.kernel.org/stable/c/ad25a115f50800c6847e0d841c5c7992a9f7c1b3"},{"url":"https://git.kernel.org/stable/c/598d9e30927b15731e83797fbd700ecf399f42dd"},{"url":"https://git.kernel.org/stable/c/9e4b7a99a03aefd37ba7bb1f022c8efab5019165"}],"title":"net: gso: fix panic on frag_list with mixed head alloc types","x_generator":{"engine":"bippy-1.2.0"}}}}