CVE-2025-38476

{"id": "CVE-2025-38476", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.8}]}, "published": "2025-07-28T12:15:29.483", "references": [{"url": "https://git.kernel.org/stable/c/034b428aa3583373a5a20b1c5931bb2b3cae1f36", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/06ec83b6c792fde1f710c1de3e836da6e257c4c4", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/62dcd9d6e61c39122d2f251a26829e2e55b0a11d", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8ba6c2362b85089b8972ac5f20b24fc71a4b8ffc", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b640daa2822a39ff76e70200cb2b7b892b896dce", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/c09e21dfc08d8afb92d9ea3bee3457adbe3ef297", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/e8101506ab86dd78f823b7028f2036a380f3a12a", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html", "tags": ["Third Party Advisory"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html", "tags": ["Third Party Advisory"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-416"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrpl: Fix use-after-free in rpl_do_srh_inline().\n\nRunning lwt_dst_cache_ref_loop.sh in selftest with KASAN triggers\nthe splat below [0].\n\nrpl_do_srh_inline() fetches ipv6_hdr(skb) and accesses it after\nskb_cow_head(), which is illegal as the header could be freed then.\n\nLet's fix it by making oldhdr to a local struct instead of a pointer.\n\n[0]:\n[root@fedora net]# ./lwt_dst_cache_ref_loop.sh\n...\nTEST: rpl (input)\n[ 57.631529] ==================================================================\nBUG: KASAN: slab-use-after-free in rpl_do_srh_inline.isra.0 (net/ipv6/rpl_iptunnel.c:174)\nRead of size 40 at addr ffff888122bf96d8 by task ping6/1543\n\nCPU: 50 UID: 0 PID: 1543 Comm: ping6 Not tainted 6.16.0-rc5-01302-gfadd1e6231b1 #23 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\nCall Trace:\n <IRQ>\n dump_stack_lvl (lib/dump_stack.c:122)\n print_report (mm/kasan/report.c:409 mm/kasan/report.c:521)\n kasan_report (mm/kasan/report.c:221 mm/kasan/report.c:636)\n kasan_check_range (mm/kasan/generic.c:175 (discriminator 1) mm/kasan/generic.c:189 (discriminator 1))\n __asan_memmove (mm/kasan/shadow.c:94 (discriminator 2))\n rpl_do_srh_inline.isra.0 (net/ipv6/rpl_iptunnel.c:174)\n rpl_input (net/ipv6/rpl_iptunnel.c:201 net/ipv6/rpl_iptunnel.c:282)\n lwtunnel_input (net/core/lwtunnel.c:459)\n ipv6_rcv (./include/net/dst.h:471 (discriminator 1) ./include/net/dst.h:469 (discriminator 1) net/ipv6/ip6_input.c:79 (discriminator 1) ./include/linux/netfilter.h:317 (discriminator 1) ./include/linux/netfilter.h:311 (discriminator 1) net/ipv6/ip6_input.c:311 (discriminator 1))\n __netif_receive_skb_one_core (net/core/dev.c:5967)\n process_backlog (./include/linux/rcupdate.h:869 net/core/dev.c:6440)\n __napi_poll.constprop.0 (net/core/dev.c:7452)\n net_rx_action (net/core/dev.c:7518 net/core/dev.c:7643)\n handle_softirqs (kernel/softirq.c:579)\n do_softirq (kernel/softirq.c:480 (discriminator 20))\n </IRQ>\n <TASK>\n __local_bh_enable_ip (kernel/softirq.c:407)\n __dev_queue_xmit (net/core/dev.c:4740)\n ip6_finish_output2 (./include/linux/netdevice.h:3358 ./include/net/neighbour.h:526 ./include/net/neighbour.h:540 net/ipv6/ip6_output.c:141)\n ip6_finish_output (net/ipv6/ip6_output.c:215 net/ipv6/ip6_output.c:226)\n ip6_output (./include/linux/netfilter.h:306 net/ipv6/ip6_output.c:248)\n ip6_send_skb (net/ipv6/ip6_output.c:1983)\n rawv6_sendmsg (net/ipv6/raw.c:588 net/ipv6/raw.c:918)\n __sys_sendto (net/socket.c:714 (discriminator 1) net/socket.c:729 (discriminator 1) net/socket.c:2228 (discriminator 1))\n __x64_sys_sendto (net/socket.c:2231)\n do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))\n entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)\nRIP: 0033:0x7f68cffb2a06\nCode: 5d e8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 75 19 83 e2 39 83 fa 08 75 11 e8 26 ff ff ff 66 0f 1f 44 00 00 48 8b 45 10 0f 05 <48> 8b 5d f8 c9 c3 0f 1f 40 00 f3 0f 1e fa 55 48 89 e5 48 83 ec 08\nRSP: 002b:00007ffefb7c53d0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c\nRAX: ffffffffffffffda RBX: 0000564cd69f10a0 RCX: 00007f68cffb2a06\nRDX: 0000000000000040 RSI: 0000564cd69f10a4 RDI: 0000000000000003\nRBP: 00007ffefb7c53f0 R08: 0000564cd6a032ac R09: 000000000000001c\nR10: 0000000000000000 R11: 0000000000000202 R12: 0000564cd69f10a4\nR13: 0000000000000040 R14: 00007ffefb7c66e0 R15: 0000564cd69f10a0\n </TASK>\n\nAllocated by task 1543:\n kasan_save_stack (mm/kasan/common.c:48)\n kasan_save_track (mm/kasan/common.c:60 (discriminator 1) mm/kasan/common.c:69 (discriminator 1))\n __kasan_slab_alloc (mm/kasan/common.c:319 mm/kasan/common.c:345)\n kmem_cache_alloc_node_noprof (./include/linux/kasan.h:250 mm/slub.c:4148 mm/slub.c:4197 mm/slub.c:4249)\n kmalloc_reserve (net/core/skbuff.c:581 (discriminator 88))\n __alloc_skb (net/core/skbuff.c:669)\n __ip6_append_data (net/ipv6/ip6_output.c:1672 (discriminator 1))\n ip6_\n---truncated---"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: rpl: Se corrige el problema de use-after-free en rpl_do_srh_inline(). Ejecutar lwt_dst_cache_ref_loop.sh en autoprueba con KASAN activa el splat debajo de [0]. rpl_do_srh_inline() recupera ipv6_hdr(skb) y accede a \u00e9l despu\u00e9s de skb_cow_head(), lo cual es ilegal, ya que la cabecera podr\u00eda liberarse en ese momento. Para solucionarlo, convertimos oldhdr en una estructura local en lugar de un puntero. [0]: [root@fedora net]# ./lwt_dst_cache_ref_loop.sh ... TEST: rpl (input) [ 57.631529] ================================================================== BUG: KASAN: slab-use-after-free in rpl_do_srh_inline.isra.0 (net/ipv6/rpl_iptunnel.c:174) Read of size 40 at addr ffff888122bf96d8 by task ping6/1543 CPU: 50 UID: 0 PID: 1543 Comm: ping6 Not tainted 6.16.0-rc5-01302-gfadd1e6231b1 #23 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: dump_stack_lvl (lib/dump_stack.c:122) print_report (mm/kasan/report.c:409 mm/kasan/report.c:521) kasan_report (mm/kasan/report.c:221 mm/kasan/report.c:636) kasan_check_range (mm/kasan/generic.c:175 (discriminator 1) mm/kasan/generic.c:189 (discriminator 1)) __asan_memmove (mm/kasan/shadow.c:94 (discriminator 2)) rpl_do_srh_inline.isra.0 (net/ipv6/rpl_iptunnel.c:174) rpl_input (net/ipv6/rpl_iptunnel.c:201 net/ipv6/rpl_iptunnel.c:282) lwtunnel_input (net/core/lwtunnel.c:459) ipv6_rcv (./include/net/dst.h:471 (discriminator 1) ./include/net/dst.h:469 (discriminator 1) net/ipv6/ip6_input.c:79 (discriminator 1) ./include/linux/netfilter.h:317 (discriminator 1) ./include/linux/netfilter.h:311 (discriminator 1) net/ipv6/ip6_input.c:311 (discriminator 1)) __netif_receive_skb_one_core (net/core/dev.c:5967) process_backlog (./include/linux/rcupdate.h:869 net/core/dev.c:6440) __napi_poll.constprop.0 (net/core/dev.c:7452) net_rx_action (net/core/dev.c:7518 net/core/dev.c:7643) handle_softirqs (kernel/softirq.c:579) do_softirq (kernel/softirq.c:480 (discriminator 20)) __local_bh_enable_ip (kernel/softirq.c:407) __dev_queue_xmit (net/core/dev.c:4740) ip6_finish_output2 (./include/linux/netdevice.h:3358 ./include/net/neighbour.h:526 ./include/net/neighbour.h:540 net/ipv6/ip6_output.c:141) ip6_finish_output (net/ipv6/ip6_output.c:215 net/ipv6/ip6_output.c:226) ip6_output (./include/linux/netfilter.h:306 net/ipv6/ip6_output.c:248) ip6_send_skb (net/ipv6/ip6_output.c:1983) rawv6_sendmsg (net/ipv6/raw.c:588 net/ipv6/raw.c:918) __sys_sendto (net/socket.c:714 (discriminator 1) net/socket.c:729 (discriminator 1) net/socket.c:2228 (discriminator 1)) __x64_sys_sendto (net/socket.c:2231) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) RIP: 0033:0x7f68cffb2a06 Code: 5d e8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 75 19 83 e2 39 83 fa 08 75 11 e8 26 ff ff ff 66 0f 1f 44 00 00 48 8b 45 10 0f 05 &lt;48&gt; 8b 5d f8 c9 c3 0f 1f 40 00 f3 0f 1e fa 55 48 89 e5 48 83 ec 08 RSP: 002b:00007ffefb7c53d0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000564cd69f10a0 RCX: 00007f68cffb2a06 RDX: 0000000000000040 RSI: 0000564cd69f10a4 RDI: 0000000000000003 RBP: 00007ffefb7c53f0 R08: 0000564cd6a032ac R09: 000000000000001c R10: 0000000000000000 R11: 0000000000000202 R12: 0000564cd69f10a4 R13: 0000000000000040 R14: 00007ffefb7c66e0 R15: 0000564cd69f10a0 Allocated by task 1543: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:60 (discriminator 1) mm/kasan/common.c:69 (discriminator 1)) __kasan_slab_alloc (mm/kasan/common.c:319 mm/kasan/common.c:345) kmem_cache_alloc_node_noprof (./include/linux/kasan.h:250 mm/slub.c:4148 mm/slub.c:4197 mm/slub.c:4249) kmalloc_reserve (net/core/skbuff.c:581 (discriminator 88)) __alloc_skb (net/core/skbuff.c:669) __ip6_append_data (net/ipv6/ip6_output.c:1672 (discriminator 1)) ip6_ ---truncated---"}], "lastModified": "2025-12-22T19:28:33.913", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "FE1D1811-AF6C-47BE-9560-6B15EFD7278D", "versionEndExcluding": "5.10.241", "versionStartIncluding": "5.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "AD9E597F-3DDE-4D7E-976C-463D0611F13F", "versionEndExcluding": "5.15.190", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A4FD62FC-0DAE-4ACE-8C9C-66156518C3E1", "versionEndExcluding": "6.1.147", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "094B81E0-B756-4727-85CA-F3F8D1C9D116", "versionEndExcluding": "6.6.100", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0099D5A4-B157-4D36-8858-982C7D579030", "versionEndExcluding": "6.12.40", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C7AFE5B0-F3B1-4D30-B8BF-EDA0385C4746", "versionEndExcluding": "6.15.8", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6D4894DB-CCFE-4602-B1BF-3960B2E19A01"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "09709862-E348-4378-8632-5A7813EDDC86"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "415BF58A-8197-43F5-B3D7-D1D63057A26E"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A0517869-312D-4429-80C2-561086E1421C"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "85421F4E-C863-4ABF-B4B4-E887CC2F7F92"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc6:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3827F0D4-5FEE-4181-B267-5A45E7CA11FC"}], "operator": "OR"}]}, {"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "FA6FEEC2-9F11-4643-8827-749718254FED"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}