{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47563 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47563 is a medium-severity use after free vulnerability in Linux kernel, published on 24 May 2024. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-47563 and fix it if it is affected.\n\nWhat it is: CVE-2021-47563 is a medium-severity use after free vulnerability in Linux kernel, published on 24 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-47563 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2021-47563/ (Markdown: https://insights.sbomify.com/CVE-2021-47563/index.md)","id":"CVE-2021-47563","markdown":"https://insights.sbomify.com/CVE-2021-47563/index.md","name":"CVE-2021-47563","record":{"aliases":["DEBIAN-CVE-2021-47563","UBUNTU-CVE-2021-47563"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel driver","requires_auth":"low_privilege","summary":"A refcount underflow in the Intel ice driver causes a use-after-free condition, leading to a kernel crash when XDP resources are rebuilt.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"cisa-adp","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nice: avoid bpf_prog refcount underflow\n\nIce driver has the routines for managing XDP resources that are shared\nbetween ndo_bpf op and VSI rebuild flow. The latter takes place for\nexample when user changes queue count on an interface via ethtool's\nset_channels().\n\nThere is an issue around the bpf_prog refcounting when VSI is being\nrebuilt - since ice_prepare_xdp_rings() is called with vsi-\u003exdp_prog as\nan argument that is used later on by ice_vsi_assign_bpf_prog(), same\nbpf_prog pointers are swapped with each other. Then it is also\ninterpreted as an 'old_prog' which in turn causes us to call\nbpf_prog_put on it that will decrement its refcount.\n\nBelow splat can be interpreted in a way that due to zero refcount of a\nbpf_prog it is wiped out from the system while kernel still tries to\nrefer to it:\n\n[  481.069429] BUG: unable to handle page fault for address: ffffc9000640f038\n[  481.077390] #PF: supervisor read access in kernel mode\n[  481.083335] #PF: error_code(0x0000) - not-present page\n[  481.089276] PGD 100000067 P4D 100000067 PUD 1001cb067 PMD 106d2b067 PTE 0\n[  481.097141] Oops: 0000 [#1] PREEMPT SMP PTI\n[  481.101980] CPU: 12 PID: 3339 Comm: sudo Tainted: G           OE     5.15.0-rc5+ #1\n[  481.110840] Hardware name: Intel Corp. GRANTLEY/GRANTLEY, BIOS GRRFCRB1.86B.0276.D07.1605190235 05/19/2016\n[  481.122021] RIP: 0010:dev_xdp_prog_id+0x25/0x40\n[  481.127265] Code: 80 00 00 00 00 0f 1f 44 00 00 89 f6 48 c1 e6 04 48 01 fe 48 8b 86 98 08 00 00 48 85 c0 74 13 48 8b 50 18 31 c0 48 85 d2 74 07 \u003c48\u003e 8b 42 38 8b 40 20 c3 48 8b 96 90 08 00 00 eb e8 66 2e 0f 1f 84\n[  481.148991] RSP: 0018:ffffc90007b63868 EFLAGS: 00010286\n[  481.155034] RAX: 0000000000000000 RBX: ffff889080824000 RCX: 0000000000000000\n[  481.163278] RDX: ffffc9000640f000 RSI: ffff889080824010 RDI: ffff889080824000\n[  481.171527] RBP: ffff888107af7d00 R08: 0000000000000000 R09: ffff88810db5f6e0\n[  481.179776] R10: 0000000000000000 R11: ffff8890885b9988 R12: ffff88810db5f4bc\n[  481.188026] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000\n[  481.196276] FS:  00007f5466d5bec0(0000) GS:ffff88903fb00000(0000) knlGS:0000000000000000\n[  481.205633] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[  481.212279] CR2: ffffc9000640f038 CR3: 000000014429c006 CR4: 00000000003706e0\n[  481.220530] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n[  481.228771] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n[  481.237029] Call Trace:\n[  481.239856]  rtnl_fill_ifinfo+0x768/0x12e0\n[  481.244602]  rtnl_dump_ifinfo+0x525/0x650\n[  481.249246]  ? __alloc_skb+0xa5/0x280\n[  481.253484]  netlink_dump+0x168/0x3c0\n[  481.257725]  netlink_recvmsg+0x21e/0x3e0\n[  481.262263]  ____sys_recvmsg+0x87/0x170\n[  481.266707]  ? __might_fault+0x20/0x30\n[  481.271046]  ? _copy_from_user+0x66/0xa0\n[  481.275591]  ? iovec_from_user+0xf6/0x1c0\n[  481.280226]  ___sys_recvmsg+0x82/0x100\n[  481.284566]  ? sock_sendmsg+0x5e/0x60\n[  481.288791]  ? __sys_sendto+0xee/0x150\n[  481.293129]  __sys_recvmsg+0x56/0xa0\n[  481.297267]  do_syscall_64+0x3b/0xc0\n[  481.301395]  entry_SYSCALL_64_after_hwframe+0x44/0xae\n[  481.307238] RIP: 0033:0x7f5466f39617\n[  481.311373] Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb bd 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2f 00 00 00 0f 05 \u003c48\u003e 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10\n[  481.342944] RSP: 002b:00007ffedc7f4308 EFLAGS: 00000246 ORIG_RAX: 000000000000002f\n[  481.361783] RAX: ffffffffffffffda RBX: 00007ffedc7f5460 RCX: 00007f5466f39617\n[  481.380278] RDX: 0000000000000000 RSI: 00007ffedc7f5360 RDI: 0000000000000003\n[  481.398500] RBP: 00007ffedc7f53f0 R08: 0000000000000000 R09: 000055d556f04d50\n[  481.416463] R10: 0000000000000077 R11: 0000000000000246 R12: 00007ffedc7f5360\n[  481.434131] R13: 00007ffedc7f5350 R14: 00007ffedc7f5344 R15: 0000000000000e98\n[  481.451520] Modules linked in: ice\n---truncated---","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"ice: avoid bpf_prog refcount underflow","id":"CVE-2021-47563","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"use_after_free","year":"2021"},"n_packages":0,"n_references":3,"next":{"headline":"net: marvell: prestera: fix double free issue on err path","id":"CVE-2021-47564"},"packages":[],"prev":{"headline":"ice: fix vsi-\u003etxq_map sizing","id":"CVE-2021-47562"},"products":["Linux"],"published":"2024-05-24","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A refcount underflow in the Intel ice driver causes a use-after-free condition, leading to a kernel crash when XDP resources are rebuilt.","url":"https://insights.sbomify.com/CVE-2021-47563/"}