{"id":"CVE-2026-45970","state":"PUBLISHED","title":"bonding: alb: fix UAF in rlb_arp_recv during bond up/down","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbonding: alb: fix UAF in rlb_arp_recv during bond up/down\n\nThe ALB RX path may access rx_hashtbl concurrently with bond\nteardown. During rapid bond up/down cycles, rlb_deinitialize()\nfrees rx_hashtbl while RX handlers are still running, leading\nto a null pointer dereference detected by KASAN.\n\nHowever, the root cause is that rlb_arp_recv() can still be accessed\nafter setting recv_probe to NULL, which is actually a use-after-free\n(UAF) issue. That is the reason for using the referenced commit in the\nFixes tag.\n\n[  214.174138] Oops: general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] SMP KASAN PTI\n[  214.186478] KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef]\n[  214.194933] CPU: 30 UID: 0 PID: 2375 Comm: ping Kdump: loaded Not tainted 6.19.0-rc8+ #2 PREEMPT(voluntary)\n[  214.205907] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS 2.14.0 01/14/2022\n[  214.214357] RIP: 0010:rlb_arp_recv+0x505/0xab0 [bonding]\n[  214.220320] Code: 0f 85 2b 05 00 00 48 b8 00 00 00 00 00 fc ff df 40 0f b6 ed 48 c1 e5 06 49 03 ad 78 01 00 00 48 8d 7d 28 48 89 fa 48 c1 ea 03 <0f> b6\n 04 02 84 c0 74 06 0f 8e 12 05 00 00 80 7d 28 00 0f 84 8c 00\n[  214.241280] RSP: 0018:ffffc900073d8870 EFLAGS: 00010206\n[  214.247116] RAX: dffffc0000000000 RBX: ffff888168556822 RCX: ffff88816855681e\n[  214.255082] RDX: 000000000000001d RSI: dffffc0000000000 RDI: 00000000000000e8\n[  214.263048] RBP: 00000000000000c0 R08: 0000000000000002 R09: ffffed11192021c8\n[  214.271013] R10: ffff8888c9010e43 R11: 0000000000000001 R12: 1ffff92000e7b119\n[  214.278978] R13: ffff8888c9010e00 R14: ffff888168556822 R15: ffff888168556810\n[  214.286943] FS:  00007f85d2d9cb80(0000) GS:ffff88886ccb3000(0000) knlGS:0000000000000000\n[  214.295966] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[  214.302380] CR2: 00007f0d047b5e34 CR3: 00000008a1c2e002 CR4: 00000000001726f0\n[  214.310347] Call Trace:\n[  214.313070]  <IRQ>\n[  214.315318]  ? __pfx_rlb_arp_recv+0x10/0x10 [bonding]\n[  214.320975]  bond_handle_frame+0x166/0xb60 [bonding]\n[  214.326537]  ? __pfx_bond_handle_frame+0x10/0x10 [bonding]\n[  214.332680]  __netif_receive_skb_core.constprop.0+0x576/0x2710\n[  214.339199]  ? __pfx_arp_process+0x10/0x10\n[  214.343775]  ? sched_balance_find_src_group+0x98/0x630\n[  214.349513]  ? __pfx___netif_receive_skb_core.constprop.0+0x10/0x10\n[  214.356513]  ? arp_rcv+0x307/0x690\n[  214.360311]  ? __pfx_arp_rcv+0x10/0x10\n[  214.364499]  ? __lock_acquire+0x58c/0xbd0\n[  214.368975]  __netif_receive_skb_one_core+0xae/0x1b0\n[  214.374518]  ? __pfx___netif_receive_skb_one_core+0x10/0x10\n[  214.380743]  ? lock_acquire+0x10b/0x140\n[  214.385026]  process_backlog+0x3f1/0x13a0\n[  214.389502]  ? process_backlog+0x3aa/0x13a0\n[  214.394174]  __napi_poll.constprop.0+0x9f/0x370\n[  214.399233]  net_rx_action+0x8c1/0xe60\n[  214.403423]  ? __pfx_net_rx_action+0x10/0x10\n[  214.408193]  ? lock_acquire.part.0+0xbd/0x260\n[  214.413058]  ? sched_clock_cpu+0x6c/0x540\n[  214.417540]  ? mark_held_locks+0x40/0x70\n[  214.421920]  handle_softirqs+0x1fd/0x860\n[  214.426302]  ? __pfx_handle_softirqs+0x10/0x10\n[  214.431264]  ? __neigh_event_send+0x2d6/0xf50\n[  214.436131]  do_softirq+0xb1/0xf0\n[  214.439830]  </IRQ>\n\nThe issue is reproducible by repeatedly running\nip link set bond0 up/down while receiving ARP messages, where\nrlb_arp_recv() can race with rlb_deinitialize() and dereference\na freed rx_hashtbl entry.\n\nFix this by setting recv_probe to NULL and then calling\nsynchronize_net() to wait for any concurrent RX processing to finish.\nThis ensures that no RX handler can access rx_hashtbl after it is freed\nin bond_alb_deinitialize().","publishedAt":"2026-05-27T12:18:29.878Z","updatedAt":"2026-10-19T19:26:40.725Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"fd54ddc929be1d6c3b3b7b35d6d4642a5d9e803c","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"de7c097800f07f3c108185c7a38b53a530ba30ff","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"db5435b5342e3aaa4521d0f3ccfe94316b253ca1","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"f94a0de7b9f32745a14a1621c63087a092823587","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"c65cdf46ce340c9c00fbbaf84599d2daff43626e","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"fef13c403be3fb685cb06419e6b3623106aab5ba","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"d31065526f160ee0244a719230aa069daca2bf4d","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"e6834a4c474697df23ab9948fd3577b26bf48656","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/bonding/bond_main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.0","versionType":"semver"},{"version":"5.10.252","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.202","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/bonding/bond_main.c"]}],"references":["https://git.kernel.org/stable/c/fd54ddc929be1d6c3b3b7b35d6d4642a5d9e803c","https://git.kernel.org/stable/c/de7c097800f07f3c108185c7a38b53a530ba30ff","https://git.kernel.org/stable/c/db5435b5342e3aaa4521d0f3ccfe94316b253ca1","https://git.kernel.org/stable/c/f94a0de7b9f32745a14a1621c63087a092823587","https://git.kernel.org/stable/c/c65cdf46ce340c9c00fbbaf84599d2daff43626e","https://git.kernel.org/stable/c/fef13c403be3fb685cb06419e6b3623106aab5ba","https://git.kernel.org/stable/c/d31065526f160ee0244a719230aa069daca2bf4d","https://git.kernel.org/stable/c/e6834a4c474697df23ab9948fd3577b26bf48656"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/45xxx/CVE-2026-45970.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45970","state":"PUBLISHED","datePublished":"2026-05-27T12:18:29.878Z","dateUpdated":"2026-10-19T19:26:40.725Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.089Z"},"containers":{"cna":{"title":"bonding: alb: fix UAF in rlb_arp_recv during bond up/down","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbonding: alb: fix UAF in rlb_arp_recv during bond up/down\n\nThe ALB RX path may access rx_hashtbl concurrently with bond\nteardown. During rapid bond up/down cycles, rlb_deinitialize()\nfrees rx_hashtbl while RX handlers are still running, leading\nto a null pointer dereference detected by KASAN.\n\nHowever, the root cause is that rlb_arp_recv() can still be accessed\nafter setting recv_probe to NULL, which is actually a use-after-free\n(UAF) issue. That is the reason for using the referenced commit in the\nFixes tag.\n\n[  214.174138] Oops: general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] SMP KASAN PTI\n[  214.186478] KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef]\n[  214.194933] CPU: 30 UID: 0 PID: 2375 Comm: ping Kdump: loaded Not tainted 6.19.0-rc8+ #2 PREEMPT(voluntary)\n[  214.205907] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS 2.14.0 01/14/2022\n[  214.214357] RIP: 0010:rlb_arp_recv+0x505/0xab0 [bonding]\n[  214.220320] Code: 0f 85 2b 05 00 00 48 b8 00 00 00 00 00 fc ff df 40 0f b6 ed 48 c1 e5 06 49 03 ad 78 01 00 00 48 8d 7d 28 48 89 fa 48 c1 ea 03 <0f> b6\n 04 02 84 c0 74 06 0f 8e 12 05 00 00 80 7d 28 00 0f 84 8c 00\n[  214.241280] RSP: 0018:ffffc900073d8870 EFLAGS: 00010206\n[  214.247116] RAX: dffffc0000000000 RBX: ffff888168556822 RCX: ffff88816855681e\n[  214.255082] RDX: 000000000000001d RSI: dffffc0000000000 RDI: 00000000000000e8\n[  214.263048] RBP: 00000000000000c0 R08: 0000000000000002 R09: ffffed11192021c8\n[  214.271013] R10: ffff8888c9010e43 R11: 0000000000000001 R12: 1ffff92000e7b119\n[  214.278978] R13: ffff8888c9010e00 R14: ffff888168556822 R15: ffff888168556810\n[  214.286943] FS:  00007f85d2d9cb80(0000) GS:ffff88886ccb3000(0000) knlGS:0000000000000000\n[  214.295966] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[  214.302380] CR2: 00007f0d047b5e34 CR3: 00000008a1c2e002 CR4: 00000000001726f0\n[  214.310347] Call Trace:\n[  214.313070]  <IRQ>\n[  214.315318]  ? __pfx_rlb_arp_recv+0x10/0x10 [bonding]\n[  214.320975]  bond_handle_frame+0x166/0xb60 [bonding]\n[  214.326537]  ? __pfx_bond_handle_frame+0x10/0x10 [bonding]\n[  214.332680]  __netif_receive_skb_core.constprop.0+0x576/0x2710\n[  214.339199]  ? __pfx_arp_process+0x10/0x10\n[  214.343775]  ? sched_balance_find_src_group+0x98/0x630\n[  214.349513]  ? __pfx___netif_receive_skb_core.constprop.0+0x10/0x10\n[  214.356513]  ? arp_rcv+0x307/0x690\n[  214.360311]  ? __pfx_arp_rcv+0x10/0x10\n[  214.364499]  ? __lock_acquire+0x58c/0xbd0\n[  214.368975]  __netif_receive_skb_one_core+0xae/0x1b0\n[  214.374518]  ? __pfx___netif_receive_skb_one_core+0x10/0x10\n[  214.380743]  ? lock_acquire+0x10b/0x140\n[  214.385026]  process_backlog+0x3f1/0x13a0\n[  214.389502]  ? process_backlog+0x3aa/0x13a0\n[  214.394174]  __napi_poll.constprop.0+0x9f/0x370\n[  214.399233]  net_rx_action+0x8c1/0xe60\n[  214.403423]  ? __pfx_net_rx_action+0x10/0x10\n[  214.408193]  ? lock_acquire.part.0+0xbd/0x260\n[  214.413058]  ? sched_clock_cpu+0x6c/0x540\n[  214.417540]  ? mark_held_locks+0x40/0x70\n[  214.421920]  handle_softirqs+0x1fd/0x860\n[  214.426302]  ? __pfx_handle_softirqs+0x10/0x10\n[  214.431264]  ? __neigh_event_send+0x2d6/0xf50\n[  214.436131]  do_softirq+0xb1/0xf0\n[  214.439830]  </IRQ>\n\nThe issue is reproducible by repeatedly running\nip link set bond0 up/down while receiving ARP messages, where\nrlb_arp_recv() can race with rlb_deinitialize() and dereference\na freed rx_hashtbl entry.\n\nFix this by setting recv_probe to NULL and then calling\nsynchronize_net() to wait for any concurrent RX processing to finish.\nThis ensures that no RX handler can access rx_hashtbl after it is freed\nin bond_alb_deinitialize()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"fd54ddc929be1d6c3b3b7b35d6d4642a5d9e803c","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"de7c097800f07f3c108185c7a38b53a530ba30ff","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"db5435b5342e3aaa4521d0f3ccfe94316b253ca1","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"f94a0de7b9f32745a14a1621c63087a092823587","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"c65cdf46ce340c9c00fbbaf84599d2daff43626e","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"fef13c403be3fb685cb06419e6b3623106aab5ba","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"d31065526f160ee0244a719230aa069daca2bf4d","versionType":"git"},{"version":"3aba891dde3842d89ad022237b99c1ed308040b0","status":"affected","lessThan":"e6834a4c474697df23ab9948fd3577b26bf48656","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/bonding/bond_main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.0","versionType":"semver"},{"version":"5.10.252","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.202","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/bonding/bond_main.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/fd54ddc929be1d6c3b3b7b35d6d4642a5d9e803c"},{"url":"https://git.kernel.org/stable/c/de7c097800f07f3c108185c7a38b53a530ba30ff"},{"url":"https://git.kernel.org/stable/c/db5435b5342e3aaa4521d0f3ccfe94316b253ca1"},{"url":"https://git.kernel.org/stable/c/f94a0de7b9f32745a14a1621c63087a092823587"},{"url":"https://git.kernel.org/stable/c/c65cdf46ce340c9c00fbbaf84599d2daff43626e"},{"url":"https://git.kernel.org/stable/c/fef13c403be3fb685cb06419e6b3623106aab5ba"},{"url":"https://git.kernel.org/stable/c/d31065526f160ee0244a719230aa069daca2bf4d"},{"url":"https://git.kernel.org/stable/c/e6834a4c474697df23ab9948fd3577b26bf48656"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable code is reached via a received ARP frame on a bond slave; an unprivileged local user can reproduce the entire scenario inside a user namespace (`unshare -Urn`) by creating a balance-alb bond over veths, injecting ARP locally, and cycling the bond up/down, so no network/adjacent position is required.\nAC:L - In the user-namespace scenario the attacker controls both sides of the race — the ARP injection (RX side) and the bond up/down cycling (free side) — and the upstream report confirms it is readily reproducible by repeated cycling, so the race can be won reliably.\nPR:L - Triggering the free requires CAP_NET_ADMIN on the bond, but this is obtainable by any unprivileged user via a user+network namespace (which also grants CAP_NET_RAW for ARP injection), so only basic local user privileges are needed.\nUI:N - No victim interaction is required; the attacker drives both the packet receipt and the bond teardown themselves.\nS:U - The vulnerability and its impact are confined to the kernel's own security authority; there is no crossing of a VM/IOMMU/sandbox boundary.\nC:H - The UAF reads the contents of the freed `rx_hashtbl` object (after potential reallocation), which can be leveraged to disclose attacker-influenced or adjacent kernel heap data.\nI:H - The UAF writes into the freed/reallocated object, including copying 6 attacker-controlled bytes (the ARP source MAC) and link-pointer updates, providing a write primitive into reclaimed heap memory exploitable for control-flow corruption.\nA:H - The bug causes a KASAN-detected general protection fault / kernel oops (as shown in the report), reliably crashing the kernel."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:28:58.557Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"5.10.252"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"5.15.202"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"6.1.165"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"6.6.128"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"6.12.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"6.18.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"6.19.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-45970","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:18:40.906017Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:26:40.725Z"}}]}}}