CVSS: -EPSS: 0%CPEs: 4EXPL: 0CVE-2021-47452 – netfilter: nf_tables: skip netdev events generated on netns removal
https://notcve.org/view.php?id=CVE-2021-47452
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: skip netdev events generated on netns removal syzbot reported following (harmless) WARN: WARNING: CPU: 1 PID: 2648 at net/netfilter/core.c:468 nft_netdev_unregister_hooks net/netfilter/nf_tables_api.c:230 [inline] nf_tables_unregister_hook include/net/netfilter/nf_tables.h:1090 [inline] __nft_release_basechain+0x138/0x640 net/netfilter/nf_tables_api.c:9524 nft_netdev_event net/netfilter/nft_chain_filter.c:351 [inline] nf_tables_netdev_event+0x521/0x8a0 net/netfilter/nft_chain_filter.c:382 reproducer: unshare -n bash -c 'ip link add br0 type bridge; nft add table netdev t ; \ nft add chain netdev t ingress \{ type filter hook ingress device "br0" \ priority 0\; policy drop\; \}' Problem is that when netns device exit hooks create the UNREGISTER event, the .pre_exit hook for nf_tables core has already removed the base hook. Notifier attempts to do this again. The need to do base hook unregister unconditionally was needed in the past, because notifier was last stage where reg->dev dereference was safe. Now that nf_tables does the hook removal in .pre_exit, this isn't needed anymore. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: netfilter: nf_tables: omitir eventos de netdev generados al eliminar netns syzbot informó lo siguiente (inofensivo) ADVERTENCIA: ADVERTENCIA: CPU: 1 PID: 2648 en net/netfilter/core.c:468 nft_netdev_unregister_hooks net/netfilter/nf_tables_api.c:230 [en línea] nf_tables_unregister_hook include/net/netfilter/nf_tables.h:1090 [en línea] __nft_release_basechain+0x138/0x640 net/netfilter/nf_tables_api.c:9524 nft_netdev_event net/netfilter/nft_ filtro_cadena.c: 351 [en línea] nf_tables_netdev_event+0x521/0x8a0 net/netfilter/nft_chain_filter.c:382 reproductor: dejar de compartir -n bash -c 'ip link agregar puente tipo br0; nft agregar tabla netdev t; \ nft add chain netdev t ingress \{ tipo filtro gancho ingreso dispositivo "br0" \ prioridad 0\; caída de la política\; \}' El problema es que cuando los ganchos de salida del dispositivo netns crean el evento UNREGISTER, el gancho .pre_exit para nf_tables core ya ha eliminado el gancho base. Notifier intenta hacer esto nuevamente. La necesidad de cancelar el registro del enlace base incondicionalmente era necesaria en el pasado, porque el notificador era la última etapa donde la desreferencia reg->dev era segura. • https://git.kernel.org/stable/c/767d1216bff82507c945e92fe719dff2083bb2f4 https://git.kernel.org/stable/c/b110391d1e806167254d3c7ae5d637191d913175 https://git.kernel.org/stable/c/0a0e5d47670b753d3dbf88f3c77a97a30864d9bd https://git.kernel.org/stable/c/90c7c58aa2bd02c65a4c63b7dfe0b16eab12cf9f https://git.kernel.org/stable/c/68a3765c659f809dcaac20030853a054646eb739 •
CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2021-47451 – netfilter: xt_IDLETIMER: fix panic that occurs when timer_type has garbage value
https://notcve.org/view.php?id=CVE-2021-47451
In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_IDLETIMER: fix panic that occurs when timer_type has garbage value Currently, when the rule related to IDLETIMER is added, idletimer_tg timer structure is initialized by kmalloc on executing idletimer_tg_create function. However, in this process timer->timer_type is not defined to a specific value. Thus, timer->timer_type has garbage value and it occurs kernel panic. So, this commit fixes the panic by initializing timer->timer_type using kzalloc instead of kmalloc. Test commands: # iptables -A OUTPUT -j IDLETIMER --timeout 1 --label test $ cat /sys/class/xt_idletimer/timers/test Killed Splat looks like: BUG: KASAN: user-memory-access in alarm_expires_remaining+0x49/0x70 Read of size 8 at addr 0000002e8c7bc4c8 by task cat/917 CPU: 12 PID: 917 Comm: cat Not tainted 5.14.0+ #3 79940a339f71eb14fc81aee1757a20d5bf13eb0e Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: dump_stack_lvl+0x6e/0x9c kasan_report.cold+0x112/0x117 ? alarm_expires_remaining+0x49/0x70 __asan_load8+0x86/0xb0 alarm_expires_remaining+0x49/0x70 idletimer_tg_show+0xe5/0x19b [xt_IDLETIMER 11219304af9316a21bee5ba9d58f76a6b9bccc6d] dev_attr_show+0x3c/0x60 sysfs_kf_seq_show+0x11d/0x1f0 ? • https://git.kernel.org/stable/c/68983a354a655c35d3fb204489d383a2a051fda7 https://git.kernel.org/stable/c/2a670c323055282c9b72794a491d53cef86bbeaf https://git.kernel.org/stable/c/cae7cab804c943d723d52724a3aeb07a3f4a2650 https://git.kernel.org/stable/c/902c0b1887522a099aa4e1e6b4b476c2fe5dd13e •
CVSS: -EPSS: 0%CPEs: 2EXPL: 0CVE-2021-47450 – KVM: arm64: Fix host stage-2 PGD refcount
https://notcve.org/view.php?id=CVE-2021-47450
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix host stage-2 PGD refcount The KVM page-table library refcounts the pages of concatenated stage-2 PGDs individually. However, when running KVM in protected mode, the host's stage-2 PGD is currently managed by EL2 as a single high-order compound page, which can cause the refcount of the tail pages to reach 0 when they shouldn't, hence corrupting the page-table. Fix this by introducing a new hyp_split_page() helper in the EL2 page allocator (matching the kernel's split_page() function), and make use of it from host_s2_zalloc_pages_exact(). En el kernel de Linux, se resolvió la siguiente vulnerabilidad: KVM: arm64: corrige el recuento de PGD de etapa 2 del host La librería de tablas de páginas de KVM vuelve a contar las páginas de los PGD de etapa 2 concatenados individualmente. Sin embargo, cuando se ejecuta KVM en modo protegido, EL2 administra actualmente el PGD de etapa 2 del host como una única página compuesta de alto orden, lo que puede causar que el recuento de las páginas finales llegue a 0 cuando no debería, corrompiendo así el tabla de páginas. Solucione este problema introduciendo un nuevo asistente hyp_split_page() en el asignador de páginas EL2 (que coincida con la función split_page() del kernel) y utilícelo desde host_s2_zalloc_pages_exact(). • https://git.kernel.org/stable/c/1025c8c0c6accfcbdc8f52ca1940160f65cd87d6 https://git.kernel.org/stable/c/b372264c66ef78f2cab44e877fbd765ad6d24c39 https://git.kernel.org/stable/c/1d58a17ef54599506d44c45ac95be27273a4d2b1 •
CVSS: 7.1EPSS: 0%CPEs: 1EXPL: 0CVE-2021-47449 – ice: fix locking for Tx timestamp tracking flush
https://notcve.org/view.php?id=CVE-2021-47449
In the Linux kernel, the following vulnerability has been resolved: ice: fix locking for Tx timestamp tracking flush Commit 4dd0d5c33c3e ("ice: add lock around Tx timestamp tracker flush") added a lock around the Tx timestamp tracker flow which is used to cleanup any left over SKBs and prepare for device removal. This lock is problematic because it is being held around a call to ice_clear_phy_tstamp. The clear function takes a mutex to send a PHY write command to firmware. This could lead to a deadlock if the mutex actually sleeps, and causes the following warning on a kernel with preemption debugging enabled: [ 715.419426] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:573 [ 715.427900] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 3100, name: rmmod [ 715.435652] INFO: lockdep is turned off. [ 715.439591] Preemption disabled at: [ 715.439594] [<0000000000000000>] 0x0 [ 715.446678] CPU: 52 PID: 3100 Comm: rmmod Tainted: G W OE 5.15.0-rc4+ #42 bdd7ec3018e725f159ca0d372ce8c2c0e784891c [ 715.458058] Hardware name: Intel Corporation S2600STQ/S2600STQ, BIOS SE5C620.86B.02.01.0010.010620200716 01/06/2020 [ 715.468483] Call Trace: [ 715.470940] dump_stack_lvl+0x6a/0x9a [ 715.474613] ___might_sleep.cold+0x224/0x26a [ 715.478895] __mutex_lock+0xb3/0x1440 [ 715.482569] ? stack_depot_save+0x378/0x500 [ 715.486763] ? ice_sq_send_cmd+0x78/0x14c0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] [ 715.494979] ? • https://git.kernel.org/stable/c/46720ac66c21bf85e08823664b7b314b85e43f26 https://git.kernel.org/stable/c/61616be899975404df44c20ab902464b60882cd7 https://git.kernel.org/stable/c/4d4a223a86afe658cd878800f09458e8bb54415d • CWE-129: Improper Validation of Array Index •
CVSS: -EPSS: 0%CPEs: 2EXPL: 0CVE-2021-47448 – mptcp: fix possible stall on recvmsg()
https://notcve.org/view.php?id=CVE-2021-47448
In the Linux kernel, the following vulnerability has been resolved: mptcp: fix possible stall on recvmsg() recvmsg() can enter an infinite loop if the caller provides the MSG_WAITALL, the data present in the receive queue is not sufficient to fulfill the request, and no more data is received by the peer. When the above happens, mptcp_wait_data() will always return with no wait, as the MPTCP_DATA_READY flag checked by such function is set and never cleared in such code path. Leveraging the above syzbot was able to trigger an RCU stall: rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=0af/1/0x4000000000000000 softirq=10678/10678 fqs=1 (t=10500 jiffies g=13089 q=109) rcu: rcu_preempt kthread starved for 10497 jiffies! g13089 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:28696 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4955 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6236 schedule+0xd3/0x270 kernel/sched/core.c:6315 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8510 Comm: syz-executor827 Not tainted 5.15.0-rc2-next-20210920-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:84 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0xc8/0x180 mm/kasan/generic.c:189 Code: 38 00 74 ed 48 8d 50 08 eb 09 48 83 c0 01 48 39 d0 74 7a 80 38 00 74 f2 48 89 c2 b8 01 00 00 00 48 85 d2 75 56 5b 5d 41 5c c3 <48> 85 d2 74 5e 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 50 80 38 00 RSP: 0018:ffffc9000cd676c8 EFLAGS: 00000283 RAX: ffffed100e9a110e RBX: ffffed100e9a110f RCX: ffffffff88ea062a RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff888074d08870 RBP: ffffed100e9a110e R08: 0000000000000001 R09: ffff888074d08877 R10: ffffed100e9a110e R11: 0000000000000000 R12: ffff888074d08000 R13: ffff888074d08000 R14: ffff888074d08088 R15: ffff888074d08000 FS: 0000555556d8e300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 S: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000180 CR3: 0000000068909000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:101 [inline] test_and_clear_bit include/asm-generic/bitops/instrumented-atomic.h:83 [inline] mptcp_release_cb+0x14a/0x210 net/mptcp/protocol.c:3016 release_sock+0xb4/0x1b0 net/core/sock.c:3204 mptcp_wait_data net/mptcp/protocol.c:1770 [inline] mptcp_recvmsg+0xfd1/0x27b0 net/mptcp/protocol.c:2080 inet6_recvmsg+0x11b/0x5e0 net/ipv6/af_inet6.c:659 sock_recvmsg_nosec net/socket.c:944 [inline] ____sys_recvmsg+0x527/0x600 net/socket.c:2626 ___sys_recvmsg+0x127/0x200 net/socket.c:2670 do_recvmmsg+0x24d/0x6d0 net/socket.c:2764 __sys_recvmmsg net/socket.c:2843 [inline] __do_sys_recvmmsg net/socket.c:2866 [inline] __se_sys_recvmmsg net/socket.c:2859 [inline] __x64_sys_recvmmsg+0x20b/0x260 net/socket.c:2859 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc200d2 ---truncated--- En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mptcp: corrige posible bloqueo en recvmsg() recvmsg() puede entrar en un bucle infinito si la persona que llama proporciona MSG_WAITALL, los datos presentes en la cola de recepción no son suficientes para cumplir con la solicitud y el par no recibe más datos. Cuando sucede lo anterior, mptcp_wait_data() siempre regresará sin espera, ya que el indicador MPTCP_DATA_READY verificado por dicha función se establece y nunca se borra en dicha ruta de código. Aprovechar el syzbot anterior fue capaz de desencadenar una parada de RCU: rcu: INFO: rcu_preempt parada autodetectada en la CPU rcu: 0-...! • https://git.kernel.org/stable/c/7a6a6cbc3e592e339ad23e4e8ede9a3f6160bda8 https://git.kernel.org/stable/c/1a4554e94f0deff9fc1dc5addf93fa579cc29711 https://git.kernel.org/stable/c/612f71d7328c14369924384ad2170aae2a6abd92 •