CVE-2021-47247 (GCVE-0-2021-47247)

Vulnerability from cvelistv5 – Published: 2024-05-21 14:19 – Updated: 2026-05-11 13:50
VLAI?
Title
net/mlx5e: Fix use-after-free of encap entry in neigh update handler
Summary
In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix use-after-free of encap entry in neigh update handler Function mlx5e_rep_neigh_update() wasn't updated to accommodate rtnl lock removal from TC filter update path and properly handle concurrent encap entry insertion/deletion which can lead to following use-after-free: [23827.464923] ================================================================== [23827.469446] BUG: KASAN: use-after-free in mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.470971] Read of size 4 at addr ffff8881d132228c by task kworker/u20:6/21635 [23827.472251] [23827.472615] CPU: 9 PID: 21635 Comm: kworker/u20:6 Not tainted 5.13.0-rc3+ #5 [23827.473788] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [23827.475639] Workqueue: mlx5e mlx5e_rep_neigh_update [mlx5_core] [23827.476731] Call Trace: [23827.477260] dump_stack+0xbb/0x107 [23827.477906] print_address_description.constprop.0+0x18/0x140 [23827.478896] ? mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.479879] ? mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.480905] kasan_report.cold+0x7c/0xd8 [23827.481701] ? mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.482744] kasan_check_range+0x145/0x1a0 [23827.493112] mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.494054] ? mlx5e_tc_tun_encap_info_equal_generic+0x140/0x140 [mlx5_core] [23827.495296] mlx5e_rep_neigh_update+0x41e/0x5e0 [mlx5_core] [23827.496338] ? mlx5e_rep_neigh_entry_release+0xb80/0xb80 [mlx5_core] [23827.497486] ? read_word_at_a_time+0xe/0x20 [23827.498250] ? strscpy+0xa0/0x2a0 [23827.498889] process_one_work+0x8ac/0x14e0 [23827.499638] ? lockdep_hardirqs_on_prepare+0x400/0x400 [23827.500537] ? pwq_dec_nr_in_flight+0x2c0/0x2c0 [23827.501359] ? rwlock_bug.part.0+0x90/0x90 [23827.502116] worker_thread+0x53b/0x1220 [23827.502831] ? process_one_work+0x14e0/0x14e0 [23827.503627] kthread+0x328/0x3f0 [23827.504254] ? _raw_spin_unlock_irq+0x24/0x40 [23827.505065] ? __kthread_bind_mask+0x90/0x90 [23827.505912] ret_from_fork+0x1f/0x30 [23827.506621] [23827.506987] Allocated by task 28248: [23827.507694] kasan_save_stack+0x1b/0x40 [23827.508476] __kasan_kmalloc+0x7c/0x90 [23827.509197] mlx5e_attach_encap+0xde1/0x1d40 [mlx5_core] [23827.510194] mlx5e_tc_add_fdb_flow+0x397/0xc40 [mlx5_core] [23827.511218] __mlx5e_add_fdb_flow+0x519/0xb30 [mlx5_core] [23827.512234] mlx5e_configure_flower+0x191c/0x4870 [mlx5_core] [23827.513298] tc_setup_cb_add+0x1d5/0x420 [23827.514023] fl_hw_replace_filter+0x382/0x6a0 [cls_flower] [23827.514975] fl_change+0x2ceb/0x4a51 [cls_flower] [23827.515821] tc_new_tfilter+0x89a/0x2070 [23827.516548] rtnetlink_rcv_msg+0x644/0x8c0 [23827.517300] netlink_rcv_skb+0x11d/0x340 [23827.518021] netlink_unicast+0x42b/0x700 [23827.518742] netlink_sendmsg+0x743/0xc20 [23827.519467] sock_sendmsg+0xb2/0xe0 [23827.520131] ____sys_sendmsg+0x590/0x770 [23827.520851] ___sys_sendmsg+0xd8/0x160 [23827.521552] __sys_sendmsg+0xb7/0x140 [23827.522238] do_syscall_64+0x3a/0x70 [23827.522907] entry_SYSCALL_64_after_hwframe+0x44/0xae [23827.523797] [23827.524163] Freed by task 25948: [23827.524780] kasan_save_stack+0x1b/0x40 [23827.525488] kasan_set_track+0x1c/0x30 [23827.526187] kasan_set_free_info+0x20/0x30 [23827.526968] __kasan_slab_free+0xed/0x130 [23827.527709] slab_free_freelist_hook+0xcf/0x1d0 [23827.528528] kmem_cache_free_bulk+0x33a/0x6e0 [23827.529317] kfree_rcu_work+0x55f/0xb70 [23827.530024] process_one_work+0x8ac/0x14e0 [23827.530770] worker_thread+0x53b/0x1220 [23827.531480] kthread+0x328/0x3f0 [23827.532114] ret_from_fork+0x1f/0x30 [23827.532785] [23827.533147] Last potentially related work creation: [23827.534007] kasan_save_stack+0x1b/0x40 [23827.534710] kasan_record_aux_stack+0xab/0xc0 [23827.535492] kvfree_call_rcu+0x31/0x7b0 [23827.536206] mlx5e_tc_del ---truncated---
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 2a1f1768fa17805ca2e937e2e034a7c3433d3bdc , < 0d1e7a7964ce6abb28883a3906bbc20fe0009f03 (git)
Affected: 2a1f1768fa17805ca2e937e2e034a7c3433d3bdc , < b6447b72aca571632e71bb73a797118d5ce46a93 (git)
Affected: 2a1f1768fa17805ca2e937e2e034a7c3433d3bdc , < fb1a3132ee1ac968316e45d21a48703a6db0b6c3 (git)
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    Linux Linux Affected: 5.4
Unaffected: 0 , < 5.4 (semver)
Unaffected: 5.10.237 , ≤ 5.10.* (semver)
Unaffected: 5.12.13 , ≤ 5.12.* (semver)
Unaffected: 5.13 , ≤ * (original_commit_for_fix)
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{
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              "content": {
                "id": "CVE-2021-47247",
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                    "Automatable": "no"
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                "role": "CISA Coordinator",
                "timestamp": "2024-05-28T15:53:08.543525Z",
                "version": "2.0.3"
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          "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",
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            "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"
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              "version": "5.12.13",
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              "status": "unaffected",
              "version": "5.13",
              "versionType": "original_commit_for_fix"
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        }
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      "cpeApplicability": [
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      "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\u0027t 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---"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T13:50:48.355Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "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"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2021-47247",
    "datePublished": "2024-05-21T14:19:44.947Z",
    "dateReserved": "2024-04-10T18:59:19.534Z",
    "dateUpdated": "2026-05-11T13:50:48.355Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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