Bugzilla – Bug 1223062
VUL-0: CVE-2024-26865: kernel: rds: tcp: Fix use-after-free of net in reqsk_timer_handler().
Last modified: 2024-07-08 14:35:53 UTC
In the Linux kernel, the following vulnerability has been resolved: rds: tcp: Fix use-after-free of net in reqsk_timer_handler(). syzkaller reported a warning of netns tracker [0] followed by KASAN splat [1] and another ref tracker warning [1]. syzkaller could not find a repro, but in the log, the only suspicious sequence was as follows: 18:26:22 executing program 1: r0 = socket$inet6_mptcp(0xa, 0x1, 0x106) ... connect$inet6(r0, &(0x7f0000000080)={0xa, 0x4001, 0x0, @loopback}, 0x1c) (async) The notable thing here is 0x4001 in connect(), which is RDS_TCP_PORT. So, the scenario would be: 1. unshare(CLONE_NEWNET) creates a per netns tcp listener in rds_tcp_listen_init(). 2. syz-executor connect()s to it and creates a reqsk. 3. syz-executor exit()s immediately. 4. netns is dismantled. [0] 5. reqsk timer is fired, and UAF happens while freeing reqsk. [1] 6. listener is freed after RCU grace period. [2] Basically, reqsk assumes that the listener guarantees netns safety until all reqsk timers are expired by holding the listener's refcount. However, this was not the case for kernel sockets. Commit 740ea3c4a0b2 ("tcp: Clean up kernel listener's reqsk in inet_twsk_purge()") fixed this issue only for per-netns ehash. Let's apply the same fix for the global ehash. [0]: ref_tracker: net notrefcnt@0000000065449cc3 has 1/1 users at sk_alloc (./include/net/net_namespace.h:337 net/core/sock.c:2146) inet6_create (net/ipv6/af_inet6.c:192 net/ipv6/af_inet6.c:119) __sock_create (net/socket.c:1572) rds_tcp_listen_init (net/rds/tcp_listen.c:279) rds_tcp_init_net (net/rds/tcp.c:577) ops_init (net/core/net_namespace.c:137) setup_net (net/core/net_namespace.c:340) copy_net_ns (net/core/net_namespace.c:497) create_new_namespaces (kernel/nsproxy.c:110) unshare_nsproxy_namespaces (kernel/nsproxy.c:228 (discriminator 4)) ksys_unshare (kernel/fork.c:3429) __x64_sys_unshare (kernel/fork.c:3496) do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) ... WARNING: CPU: 0 PID: 27 at lib/ref_tracker.c:179 ref_tracker_dir_exit (lib/ref_tracker.c:179) [1]: BUG: KASAN: slab-use-after-free in inet_csk_reqsk_queue_drop (./include/net/inet_hashtables.h:180 net/ipv4/inet_connection_sock.c:952 net/ipv4/inet_connection_sock.c:966) Read of size 8 at addr ffff88801b370400 by task swapper/0/0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Call Trace: <IRQ> dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1)) print_report (mm/kasan/report.c:378 mm/kasan/report.c:488) kasan_report (mm/kasan/report.c:603) inet_csk_reqsk_queue_drop (./include/net/inet_hashtables.h:180 net/ipv4/inet_connection_sock.c:952 net/ipv4/inet_connection_sock.c:966) reqsk_timer_handler (net/ipv4/inet_connection_sock.c:979 net/ipv4/inet_connection_sock.c:1092) call_timer_fn (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/timer.h:127 kernel/time/timer.c:1701) __run_timers.part.0 (kernel/time/timer.c:1752 kernel/time/timer.c:2038) run_timer_softirq (kernel/time/timer.c:2053) __do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:554) irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632 kernel/softirq.c:644) sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1076 (discriminator 14)) </IRQ> Allocated by task 258 on cpu 0 at 83.612050s: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:68) __kasan_slab_alloc (mm/kasan/common.c:343) kmem_cache_alloc (mm/slub.c:3813 mm/slub.c:3860 mm/slub.c:3867) copy_net_ns (./include/linux/slab.h:701 net/core/net_namespace.c:421 net/core/net_namespace.c:480) create_new_namespaces (kernel/nsproxy.c:110) unshare_nsproxy_name ---truncated--- References: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-26865 https://www.cve.org/CVERecord?id=CVE-2024-26865 https://git.kernel.org/stable/c/1e9fd5cf8d7f487332560f7bb312fc7d416817f3 https://git.kernel.org/stable/c/2a750d6a5b365265dbda33330a6188547ddb5c24 https://git.kernel.org/stable/c/9905a157048f441f1412e7bd13372f4a971d75c6 https://git.kernel.org/stable/c/9ceac040506a05a30b104b2aa2e9146810704500 https://git.kernel.org/stable/c/f901ee07853ce97e9f1104c7c898fbbe447f0279 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-26865.mbox https://bugzilla.redhat.com/show_bug.cgi?id=2275721
The Fixes tag refers to mainline commit 467fa15356ac ("RDS-TCP: Support multiple RDS-TCP listen endpoints, one per netns.") from 4.3-rc1. However, based on the fix and description of the scenario, I believe that the issue was in fact only introduced in 6.1-rc1 by commit edc12f032a5a ("tcp: Save unnecessary inet_twsk_purge() calls."). This is also supported by the fact that the fix has been backported into stable 6.1 but not into 5.15 or any older actively maintained stable branches. Therefore I'm only going to submit the fix for SLE15-SP6-GA (mainline commit edc12f032a5a has not been backported into any older branch).
introduced edc12f032a5a 6.1-rc1 fixed 2a750d6a5b36 6.9-rc1 stable 6.8.2 SLE15-SP6-GA 4df5c351ddcf The fix has been submitted to all relevant branches and references were added to stable branch (which received the fix via stable updates). Reassigning back to security team.
SUSE-SU-2024:2184-1: An update that solves 198 vulnerabilities and has 28 security fixes can now be installed. Category: security (important) Bug References: 1065729, 1101816, 1141539, 1181674, 1185902, 1187716, 1188616, 1190317, 1190795, 1191452, 1194591, 1197760, 1197894, 1203935, 1206213, 1206646, 1207186, 1209657, 1210335, 1215702, 1216702, 1217169, 1217519, 1218917, 1220487, 1220513, 1220854, 1220928, 1221044, 1221081, 1221086, 1221543, 1221545, 1221816, 1221977, 1221994, 1222559, 1222619, 1222627, 1222667, 1222671, 1222793, 1222893, 1222894, 1223023, 1223046, 1223048, 1223062, 1223084, 1223119, 1223138, 1223207, 1223360, 1223384, 1223432, 1223509, 1223512, 1223539, 1223540, 1223626, 1223627, 1223633, 1223653, 1223666, 1223671, 1223712, 1223715, 1223738, 1223744, 1223752, 1223802, 1223819, 1223834, 1223922, 1223923, 1223931, 1223932, 1223948, 1223969, 1224096, 1224174, 1224181, 1224347, 1224482, 1224511, 1224525, 1224566, 1224580, 1224592, 1224601, 1224607, 1224621, 1224644, 1224645, 1224648, 1224650, 1224663, 1224671, 1224676, 1224680, 1224682, 1224725, 1224728, 1224733, 1224738, 1224747, 1224749, 1224759, 1224803, 1224827, 1224830, 1224831, 1224834, 1224838, 1224841, 1224844, 1224846, 1224847, 1224849, 1224854, 1224859, 1224867, 1224880, 1224882, 1224888, 1224889, 1224892, 1224893, 1224899, 1224904, 1224907, 1224916, 1224917, 1224922, 1224926, 1224930, 1224931, 1224942, 1224954, 1224956, 1224957, 1224959, 1224960, 1224961, 1224963, 1224966, 1224968, 1224981, 1224982, 1224983, 1224987, 1224990, 1224996, 1225008, 1225009, 1225010, 1225022, 1225026, 1225030, 1225054, 1225058, 1225059, 1225060, 1225062, 1225082, 1225084, 1225086, 1225092, 1225096, 1225112, 1225124, 1225128, 1225132, 1225141, 1225143, 1225144, 1225151, 1225153, 1225155, 1225157, 1225164, 1225177, 1225189, 1225192, 1225193, 1225198, 1225201, 1225207, 1225208, 1225222, 1225230, 1225242, 1225244, 1225247, 1225251, 1225252, 1225256, 1225303, 1225318, 1225322, 1225329, 1225330, 1225336, 1225347, 1225351, 1225354, 1225355, 1225360, 1225366, 1225367, 1225384, 1225390, 1225404, 1225409, 1225411, 1225438, 1225453, 1225479, 1225482, 1225506, 1225549, 1225560, 1225572, 1225640, 1225708, 1225764 CVE References: CVE-2021-46933, CVE-2021-46955, CVE-2021-47074, CVE-2021-47113, CVE-2021-47131, CVE-2021-47162, CVE-2021-47171, CVE-2021-47188, CVE-2021-47206, CVE-2021-47220, CVE-2021-47229, CVE-2021-47231, CVE-2021-47235, CVE-2021-47236, CVE-2021-47237, CVE-2021-47238, CVE-2021-47239, CVE-2021-47245, CVE-2021-47246, CVE-2021-47248, CVE-2021-47249, CVE-2021-47250, CVE-2021-47252, CVE-2021-47254, CVE-2021-47258, CVE-2021-47260, CVE-2021-47261, CVE-2021-47265, CVE-2021-47269, CVE-2021-47274, CVE-2021-47276, CVE-2021-47277, CVE-2021-47280, CVE-2021-47281, CVE-2021-47284, CVE-2021-47285, CVE-2021-47288, CVE-2021-47301, CVE-2021-47302, CVE-2021-47305, CVE-2021-47307, CVE-2021-47308, CVE-2021-47310, CVE-2021-47311, CVE-2021-47314, CVE-2021-47315, CVE-2021-47319, CVE-2021-47320, CVE-2021-47321, CVE-2021-47323, CVE-2021-47324, CVE-2021-47330, CVE-2021-47334, CVE-2021-47337, CVE-2021-47343, CVE-2021-47344, CVE-2021-47345, CVE-2021-47347, CVE-2021-47352, CVE-2021-47353, CVE-2021-47355, CVE-2021-47356, CVE-2021-47357, CVE-2021-47361, CVE-2021-47362, CVE-2021-47369, CVE-2021-47375, CVE-2021-47378, CVE-2021-47382, CVE-2021-47383, CVE-2021-47391, CVE-2021-47397, CVE-2021-47400, CVE-2021-47401, CVE-2021-47404, CVE-2021-47409, CVE-2021-47416, CVE-2021-47423, CVE-2021-47424, CVE-2021-47431, CVE-2021-47435, CVE-2021-47436, CVE-2021-47456, CVE-2021-47458, CVE-2021-47460, CVE-2021-47469, CVE-2021-47472, CVE-2021-47473, CVE-2021-47478, CVE-2021-47480, CVE-2021-47483, CVE-2021-47485, CVE-2021-47495, CVE-2021-47496, CVE-2021-47497, CVE-2021-47500, CVE-2021-47506, CVE-2021-47509, CVE-2021-47511, CVE-2021-47523, CVE-2021-47541, CVE-2021-47548, CVE-2021-47565, CVE-2022-48636, CVE-2022-48650, CVE-2022-48672, CVE-2022-48686, CVE-2022-48697, CVE-2022-48702, CVE-2022-48704, CVE-2022-48708, CVE-2022-48710, CVE-2023-0160, CVE-2023-1829, CVE-2023-42755, CVE-2023-47233, CVE-2023-52527, CVE-2023-52586, CVE-2023-52591, CVE-2023-52646, CVE-2023-52653, CVE-2023-52655, CVE-2023-52664, CVE-2023-52685, CVE-2023-52686, CVE-2023-52691, CVE-2023-52696, CVE-2023-52698, CVE-2023-52703, CVE-2023-52730, CVE-2023-52732, CVE-2023-52741, CVE-2023-52742, CVE-2023-52747, CVE-2023-52759, CVE-2023-52774, CVE-2023-52781, CVE-2023-52796, CVE-2023-52803, CVE-2023-52821, CVE-2023-52864, CVE-2023-52865, CVE-2023-52867, CVE-2023-52875, CVE-2023-52880, CVE-2024-0639, CVE-2024-26625, CVE-2024-26739, CVE-2024-26752, CVE-2024-26775, CVE-2024-26791, CVE-2024-26828, CVE-2024-26846, CVE-2024-26874, CVE-2024-26876, CVE-2024-26900, CVE-2024-26915, CVE-2024-26920, CVE-2024-26921, CVE-2024-26929, CVE-2024-26930, CVE-2024-26931, CVE-2024-26934, CVE-2024-26957, CVE-2024-26958, CVE-2024-26984, CVE-2024-26996, CVE-2024-27008, CVE-2024-27054, CVE-2024-27059, CVE-2024-27062, CVE-2024-27388, CVE-2024-27396, CVE-2024-27398, CVE-2024-27401, CVE-2024-27419, CVE-2024-27436, CVE-2024-35789, CVE-2024-35791, CVE-2024-35809, CVE-2024-35811, CVE-2024-35830, CVE-2024-35849, CVE-2024-35877, CVE-2024-35878, CVE-2024-35887, CVE-2024-35895, CVE-2024-35914, CVE-2024-35932, CVE-2024-35935, CVE-2024-35936, CVE-2024-35944, CVE-2024-35955, CVE-2024-35969, CVE-2024-35982, CVE-2024-36015, CVE-2024-36029, CVE-2024-36954 Maintenance Incident: [SUSE:Maintenance:34269](https://smelt.suse.de/incident/34269/) Sources used: SUSE Linux Enterprise Live Patching 12-SP5 (src): kgraft-patch-SLE12-SP5_Update_57-1-8.3.1 SUSE Linux Enterprise Software Development Kit 12 SP5 (src): kernel-obs-build-4.12.14-122.219.1 SUSE Linux Enterprise High Performance Computing 12 SP5 (src): kernel-source-4.12.14-122.219.1, kernel-syms-4.12.14-122.219.1 SUSE Linux Enterprise Server 12 SP5 (src): kernel-source-4.12.14-122.219.1, kernel-syms-4.12.14-122.219.1 SUSE Linux Enterprise Server for SAP Applications 12 SP5 (src): kernel-source-4.12.14-122.219.1, kernel-syms-4.12.14-122.219.1 NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.