{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47247","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-04-10T18:59:19.534Z","datePublished":"2024-05-21T14:19:44.947Z","dateUpdated":"2026-05-11T13:50:48.355Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T13:50:48.355Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix use-after-free of encap entry in neigh update handler\n\nFunction mlx5e_rep_neigh_update() wasn't updated to accommodate rtnl lock\nremoval from TC filter update path and properly handle concurrent encap\nentry insertion/deletion which can lead to following use-after-free:\n\n [23827.464923] ==================================================================\n [23827.469446] BUG: KASAN: use-after-free in mlx5e_encap_take+0x72/0x140 [mlx5_core]\n [23827.470971] Read of size 4 at addr ffff8881d132228c by task kworker/u20:6/21635\n [23827.472251]\n [23827.472615] CPU: 9 PID: 21635 Comm: kworker/u20:6 Not tainted 5.13.0-rc3+ #5\n [23827.473788] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014\n [23827.475639] Workqueue: mlx5e mlx5e_rep_neigh_update [mlx5_core]\n [23827.476731] Call Trace:\n [23827.477260]  dump_stack+0xbb/0x107\n [23827.477906]  print_address_description.constprop.0+0x18/0x140\n [23827.478896]  ? mlx5e_encap_take+0x72/0x140 [mlx5_core]\n [23827.479879]  ? mlx5e_encap_take+0x72/0x140 [mlx5_core]\n [23827.480905]  kasan_report.cold+0x7c/0xd8\n [23827.481701]  ? mlx5e_encap_take+0x72/0x140 [mlx5_core]\n [23827.482744]  kasan_check_range+0x145/0x1a0\n [23827.493112]  mlx5e_encap_take+0x72/0x140 [mlx5_core]\n [23827.494054]  ? mlx5e_tc_tun_encap_info_equal_generic+0x140/0x140 [mlx5_core]\n [23827.495296]  mlx5e_rep_neigh_update+0x41e/0x5e0 [mlx5_core]\n [23827.496338]  ? mlx5e_rep_neigh_entry_release+0xb80/0xb80 [mlx5_core]\n [23827.497486]  ? read_word_at_a_time+0xe/0x20\n [23827.498250]  ? strscpy+0xa0/0x2a0\n [23827.498889]  process_one_work+0x8ac/0x14e0\n [23827.499638]  ? lockdep_hardirqs_on_prepare+0x400/0x400\n [23827.500537]  ? pwq_dec_nr_in_flight+0x2c0/0x2c0\n [23827.501359]  ? rwlock_bug.part.0+0x90/0x90\n [23827.502116]  worker_thread+0x53b/0x1220\n [23827.502831]  ? process_one_work+0x14e0/0x14e0\n [23827.503627]  kthread+0x328/0x3f0\n [23827.504254]  ? _raw_spin_unlock_irq+0x24/0x40\n [23827.505065]  ? __kthread_bind_mask+0x90/0x90\n [23827.505912]  ret_from_fork+0x1f/0x30\n [23827.506621]\n [23827.506987] Allocated by task 28248:\n [23827.507694]  kasan_save_stack+0x1b/0x40\n [23827.508476]  __kasan_kmalloc+0x7c/0x90\n [23827.509197]  mlx5e_attach_encap+0xde1/0x1d40 [mlx5_core]\n [23827.510194]  mlx5e_tc_add_fdb_flow+0x397/0xc40 [mlx5_core]\n [23827.511218]  __mlx5e_add_fdb_flow+0x519/0xb30 [mlx5_core]\n [23827.512234]  mlx5e_configure_flower+0x191c/0x4870 [mlx5_core]\n [23827.513298]  tc_setup_cb_add+0x1d5/0x420\n [23827.514023]  fl_hw_replace_filter+0x382/0x6a0 [cls_flower]\n [23827.514975]  fl_change+0x2ceb/0x4a51 [cls_flower]\n [23827.515821]  tc_new_tfilter+0x89a/0x2070\n [23827.516548]  rtnetlink_rcv_msg+0x644/0x8c0\n [23827.517300]  netlink_rcv_skb+0x11d/0x340\n [23827.518021]  netlink_unicast+0x42b/0x700\n [23827.518742]  netlink_sendmsg+0x743/0xc20\n [23827.519467]  sock_sendmsg+0xb2/0xe0\n [23827.520131]  ____sys_sendmsg+0x590/0x770\n [23827.520851]  ___sys_sendmsg+0xd8/0x160\n [23827.521552]  __sys_sendmsg+0xb7/0x140\n [23827.522238]  do_syscall_64+0x3a/0x70\n [23827.522907]  entry_SYSCALL_64_after_hwframe+0x44/0xae\n [23827.523797]\n [23827.524163] Freed by task 25948:\n [23827.524780]  kasan_save_stack+0x1b/0x40\n [23827.525488]  kasan_set_track+0x1c/0x30\n [23827.526187]  kasan_set_free_info+0x20/0x30\n [23827.526968]  __kasan_slab_free+0xed/0x130\n [23827.527709]  slab_free_freelist_hook+0xcf/0x1d0\n [23827.528528]  kmem_cache_free_bulk+0x33a/0x6e0\n [23827.529317]  kfree_rcu_work+0x55f/0xb70\n [23827.530024]  process_one_work+0x8ac/0x14e0\n [23827.530770]  worker_thread+0x53b/0x1220\n [23827.531480]  kthread+0x328/0x3f0\n [23827.532114]  ret_from_fork+0x1f/0x30\n [23827.532785]\n [23827.533147] Last potentially related work creation:\n [23827.534007]  kasan_save_stack+0x1b/0x40\n [23827.534710]  kasan_record_aux_stack+0xab/0xc0\n [23827.535492]  kvfree_call_rcu+0x31/0x7b0\n [23827.536206]  mlx5e_tc_del\n---truncated---"}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/mellanox/mlx5/core/en/rep/neigh.c","drivers/net/ethernet/mellanox/mlx5/core/en/rep/tc.c","drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c","drivers/net/ethernet/mellanox/mlx5/core/en_tc.h"],"versions":[{"version":"2a1f1768fa17805ca2e937e2e034a7c3433d3bdc","lessThan":"0d1e7a7964ce6abb28883a3906bbc20fe0009f03","status":"affected","versionType":"git"},{"version":"2a1f1768fa17805ca2e937e2e034a7c3433d3bdc","lessThan":"b6447b72aca571632e71bb73a797118d5ce46a93","status":"affected","versionType":"git"},{"version":"2a1f1768fa17805ca2e937e2e034a7c3433d3bdc","lessThan":"fb1a3132ee1ac968316e45d21a48703a6db0b6c3","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/mellanox/mlx5/core/en/rep/neigh.c","drivers/net/ethernet/mellanox/mlx5/core/en/rep/tc.c","drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c","drivers/net/ethernet/mellanox/mlx5/core/en_tc.h"],"versions":[{"version":"5.4","status":"affected"},{"version":"0","lessThan":"5.4","status":"unaffected","versionType":"semver"},{"version":"5.10.237","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.12.13","lessThanOrEqual":"5.12.*","status":"unaffected","versionType":"semver"},{"version":"5.13","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":"5.4","versionEndExcluding":"5.10.237"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4","versionEndExcluding":"5.12.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4","versionEndExcluding":"5.13"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/0d1e7a7964ce6abb28883a3906bbc20fe0009f03"},{"url":"https://git.kernel.org/stable/c/b6447b72aca571632e71bb73a797118d5ce46a93"},{"url":"https://git.kernel.org/stable/c/fb1a3132ee1ac968316e45d21a48703a6db0b6c3"}],"title":"net/mlx5e: Fix use-after-free of encap entry in neigh update handler","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2021-47247","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-05-28T15:53:08.543525Z"}}}],"providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-06-04T17:15:17.168Z"}},{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/b6447b72aca571632e71bb73a797118d5ce46a93","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/fb1a3132ee1ac968316e45d21a48703a6db0b6c3","tags":["x_transferred"]},{"url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html"}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2025-11-03T19:26:38.429Z"}}]}}