keycloak before version 4.0.0.final is vulnerable to a infinite loop in session replacement. A Keycloak cluster with multiple nodes could mishandle an expired session replacement and lead to an infinite loop. A malicious authenticated user could use this flaw to achieve Denial of Service on the server.

A flaw was found in the Linux kernel present since v4.0-rc1 and through v4.13-rc4. A crafted network packet sent remotely by an attacker may force the kernel to enter an infinite loop in the cipso_v4_optptr() function in net/ipv4/cipso_ipv4.c leading to a denial-of-service. A certain non-default configuration of LSM (Linux Security Module) and NetLabel should be set up on a system before an attacker could leverage this flaw.

A denial of service vulnerability exists in Jenkins 2.153 and earlier, LTS 2.138.3 and earlier in CronTab.java that allows attackers with Overall/Read permission to have a request handling thread enter an infinite loop.

smbd in Samba before 4.4.10 and 4.5.x before 4.5.6 has a denial of service vulnerability (fd_open_atomic infinite loop with high CPU usage and memory consumption) due to wrongly handling dangling symlinks.

The ip6_find_1stfragopt function in net/ipv6/output_core.c in the Linux kernel through 4.12.3 allows local users to cause a denial of service (integer overflow and infinite loop) by leveraging the ability to open a raw socket.

crypto/ahash.c in the Linux kernel through 4.10.9 allows attackers to cause a denial of service (API operation calling its own callback, and infinite recursion) by triggering EBUSY on a full queue.

In the Linux kernel, the following vulnerability has been resolved: virtio_net: Do not send RSS key if it is not supported There is a bug when setting the RSS options in virtio_net that can break the whole machine, getting the kernel into an infinite loop. Running the following command in any QEMU virtual machine with virtionet will reproduce this problem: # ethtool -X eth0 hfunc toeplitz This is how the problem happens: 1) ethtool_set_rxfh() calls virtnet_set_rxfh() 2) virtnet_set_rxfh() calls virtnet_commit_rss_command() 3) virtnet_commit_rss_command() populates 4 entries for the rss scatter-gather 4) Since the command above does not have a key, then the last scatter-gatter entry will be zeroed, since rss_key_size == 0. sg_buf_size = vi->rss_key_size; 5) This buffer is passed to qemu, but qemu is not happy with a buffer with zero length, and do the following in virtqueue_map_desc() (QEMU function): if (!sz) { virtio_error(vdev, "virtio: zero sized buffers are not allowed"); 6) virtio_error() (also QEMU function) set the device as broken vdev->broken = true; 7) Qemu bails out, and do not repond this crazy kernel. 8) The kernel is waiting for the response to come back (function virtnet_send_command()) 9) The kernel is waiting doing the following : while (!virtqueue_get_buf(vi->cvq, &tmp) && !virtqueue_is_broken(vi->cvq)) cpu_relax(); 10) None of the following functions above is true, thus, the kernel loops here forever. Keeping in mind that virtqueue_is_broken() does not look at the qemu `vdev->broken`, so, it never realizes that the vitio is broken at QEMU side. Fix it by not sending RSS commands if the feature is not available in the device.

The xhci_kick_epctx function in hw/usb/hcd-xhci.c in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (infinite loop and QEMU process crash) via vectors related to control transfer descriptor sequence.

The tcp_splice_read function in net/ipv4/tcp.c in the Linux kernel before 4.9.11 allows remote attackers to cause a denial of service (infinite loop and soft lockup) via vectors involving a TCP packet with the URG flag.

It was found in Undertow before 1.3.28 that with non-clean TCP close, the Websocket server gets into infinite loop on every IO thread, effectively causing DoS.

In the Linux kernel, the following vulnerability has been resolved: x86/fpu: Stop relying on userspace for info to fault in xsave buffer Before this change, the expected size of the user space buffer was taken from fx_sw->xstate_size. fx_sw->xstate_size can be changed from user-space, so it is possible construct a sigreturn frame where: * fx_sw->xstate_size is smaller than the size required by valid bits in fx_sw->xfeatures. * user-space unmaps parts of the sigrame fpu buffer so that not all of the buffer required by xrstor is accessible. In this case, xrstor tries to restore and accesses the unmapped area which results in a fault. But fault_in_readable succeeds because buf + fx_sw->xstate_size is within the still mapped area, so it goes back and tries xrstor again. It will spin in this loop forever. Instead, fault in the maximum size which can be touched by XRSTOR (taken from fpstate->user_size). [ dhansen: tweak subject / changelog ]

It was found that when Keycloak before 2.5.5 receives a Logout request with a Extensions in the middle of the request, the SAMLSloRequestParser.parse() method ends in a infinite loop. An attacker could use this flaw to conduct denial of service attacks.

In the Linux kernel, the following vulnerability has been resolved: netdevsim: avoid potential loop in nsim_dev_trap_report_work() Many syzbot reports include the following trace [1] If nsim_dev_trap_report_work() can not grab the mutex, it should rearm itself at least one jiffie later. [1] Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 32383 Comm: kworker/0:2 Not tainted 6.8.0-rc2-syzkaller-00031-g861c0981648f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: events nsim_dev_trap_report_work RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:89 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x101/0x190 mm/kasan/generic.c:189 Code: 07 49 39 d1 75 0a 45 3a 11 b8 01 00 00 00 7c 0b 44 89 c2 e8 21 ed ff ff 83 f0 01 5b 5d 41 5c c3 48 85 d2 74 4f 48 01 ea eb 09 <48> 83 c0 01 48 39 d0 74 41 80 38 00 74 f2 eb b6 41 bc 08 00 00 00 RSP: 0018:ffffc90012dcf998 EFLAGS: 00000046 RAX: fffffbfff258af1e RBX: fffffbfff258af1f RCX: ffffffff8168eda3 RDX: fffffbfff258af1f RSI: 0000000000000004 RDI: ffffffff92c578f0 RBP: fffffbfff258af1e R08: 0000000000000000 R09: fffffbfff258af1e R10: ffffffff92c578f3 R11: ffffffff8acbcbc0 R12: 0000000000000002 R13: ffff88806db38400 R14: 1ffff920025b9f42 R15: ffffffff92c578e8 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c00994e078 CR3: 000000002c250000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] queued_spin_is_locked include/asm-generic/qspinlock.h:57 [inline] debug_spin_unlock kernel/locking/spinlock_debug.c:101 [inline] do_raw_spin_unlock+0x53/0x230 kernel/locking/spinlock_debug.c:141 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock_irqrestore+0x22/0x70 kernel/locking/spinlock.c:194 debug_object_activate+0x349/0x540 lib/debugobjects.c:726 debug_work_activate kernel/workqueue.c:578 [inline] insert_work+0x30/0x230 kernel/workqueue.c:1650 __queue_work+0x62e/0x11d0 kernel/workqueue.c:1802 __queue_delayed_work+0x1bf/0x270 kernel/workqueue.c:1953 queue_delayed_work_on+0x106/0x130 kernel/workqueue.c:1989 queue_delayed_work include/linux/workqueue.h:563 [inline] schedule_delayed_work include/linux/workqueue.h:677 [inline] nsim_dev_trap_report_work+0x9c0/0xc80 drivers/net/netdevsim/dev.c:842 process_one_work+0x886/0x15d0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2787 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 </TASK>

The FoFiType1C::cvtGlyph function in fofi/FoFiType1C.cc in Poppler through 0.64.0 allows remote attackers to cause a denial of service (infinite recursion) via a crafted PDF file, as demonstrated by pdftops.

The arch_timer_reg_read_stable macro in arch/arm64/include/asm/arch_timer.h in the Linux kernel before 4.13 allows local users to cause a denial of service (infinite recursion) by writing to a file under /sys/kernel/debug in certain circumstances, as demonstrated by a scenario involving debugfs, ftrace, PREEMPT_TRACER, and FUNCTION_GRAPH_TRACER.

The inet_diag_bc_audit function in net/ipv4/inet_diag.c in the Linux kernel before 2.6.39.3 does not properly audit INET_DIAG bytecode, which allows local users to cause a denial of service (kernel infinite loop) via crafted INET_DIAG_REQ_BYTECODE instructions in a netlink message, as demonstrated by an INET_DIAG_BC_JMP instruction with a zero yes value, a different vulnerability than CVE-2010-3880.

In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mvm: fix 6 GHz scan construction If more than 255 colocated APs exist for the set of all APs found during 2.4/5 GHz scanning, then the 6 GHz scan construction will loop forever since the loop variable has type u8, which can never reach the number found when that's bigger than 255, and is stored in a u32 variable. Also move it into the loops to have a smaller scope. Using a u32 there is fine, we limit the number of APs in the scan list and each has a limit on the number of RNR entries due to the frame size. With a limit of 1000 scan results, a frame size upper bound of 4096 (really it's more like ~2300) and a TBTT entry size of at least 11, we get an upper bound for the number of ~372k, well in the bounds of a u32.

In the Linux kernel, the following vulnerability has been resolved: x86/bhi: Avoid warning in #DB handler due to BHI mitigation When BHI mitigation is enabled, if SYSENTER is invoked with the TF flag set then entry_SYSENTER_compat() uses CLEAR_BRANCH_HISTORY and calls the clear_bhb_loop() before the TF flag is cleared. This causes the #DB handler (exc_debug_kernel()) to issue a warning because single-step is used outside the entry_SYSENTER_compat() function. To address this issue, entry_SYSENTER_compat() should use CLEAR_BRANCH_HISTORY after making sure the TF flag is cleared. The problem can be reproduced with the following sequence: $ cat sysenter_step.c int main() { asm("pushf; pop %ax; bts $8,%ax; push %ax; popf; sysenter"); } $ gcc -o sysenter_step sysenter_step.c $ ./sysenter_step Segmentation fault (core dumped) The program is expected to crash, and the #DB handler will issue a warning. Kernel log: WARNING: CPU: 27 PID: 7000 at arch/x86/kernel/traps.c:1009 exc_debug_kernel+0xd2/0x160 ... RIP: 0010:exc_debug_kernel+0xd2/0x160 ... Call Trace: <#DB> ? show_regs+0x68/0x80 ? __warn+0x8c/0x140 ? exc_debug_kernel+0xd2/0x160 ? report_bug+0x175/0x1a0 ? handle_bug+0x44/0x90 ? exc_invalid_op+0x1c/0x70 ? asm_exc_invalid_op+0x1f/0x30 ? exc_debug_kernel+0xd2/0x160 exc_debug+0x43/0x50 asm_exc_debug+0x1e/0x40 RIP: 0010:clear_bhb_loop+0x0/0xb0 ... </#DB> <TASK> ? entry_SYSENTER_compat_after_hwframe+0x6e/0x8d </TASK> [ bp: Massage commit message. ]

In the Linux kernel, the following vulnerability has been resolved: x86/sgx: Fix deadlock in SGX NUMA node search When the current node doesn't have an EPC section configured by firmware and all other EPC sections are used up, CPU can get stuck inside the while loop that looks for an available EPC page from remote nodes indefinitely, leading to a soft lockup. Note how nid_of_current will never be equal to nid in that while loop because nid_of_current is not set in sgx_numa_mask. Also worth mentioning is that it's perfectly fine for the firmware not to setup an EPC section on a node. While setting up an EPC section on each node can enhance performance, it is not a requirement for functionality. Rework the loop to start and end on *a* node that has SGX memory. This avoids the deadlock looking for the current SGX-lacking node to show up in the loop when it never will.

In the Linux kernel, the following vulnerability has been resolved: ASoC: Intel: soc-acpi-intel-rpl-match: add missing empty item There is no links_num in struct snd_soc_acpi_mach {}, and we test !link->num_adr as a condition to end the loop in hda_sdw_machine_select(). So an empty item in struct snd_soc_acpi_link_adr array is required.

In the Linux kernel, the following vulnerability has been resolved: ext4: fix infinite loop when replaying fast_commit When doing fast_commit replay an infinite loop may occur due to an uninitialized extent_status struct. ext4_ext_determine_insert_hole() does not detect the replay and calls ext4_es_find_extent_range(), which will return immediately without initializing the 'es' variable. Because 'es' contains garbage, an integer overflow may happen causing an infinite loop in this function, easily reproducible using fstest generic/039. This commit fixes this issue by unconditionally initializing the structure in function ext4_es_find_extent_range(). Thanks to Zhang Yi, for figuring out the real problem!

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Fix loop termination condition in gss_free_in_token_pages() The in_token->pages[] array is not NULL terminated. This results in the following KASAN splat: KASAN: maybe wild-memory-access in range [0x04a2013400000008-0x04a201340000000f]

The intel_hda_xfer function in hw/audio/intel-hda.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (infinite loop and CPU consumption) via an entry with the same value for buffer length and pointer position.

The rtl8139_cplus_transmit function in hw/net/rtl8139.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (infinite loop and CPU consumption) by leveraging failure to limit the ring descriptor count.

In the Linux kernel, the following vulnerability has been resolved: RDMA/core: Fix ib block iterator counter overflow When registering a new DMA MR after selecting the best aligned page size for it, we iterate over the given sglist to split each entry to smaller, aligned to the selected page size, DMA blocks. In given circumstances where the sg entry and page size fit certain sizes and the sg entry is not aligned to the selected page size, the total size of the aligned pages we need to cover the sg entry is >= 4GB. Under this circumstances, while iterating page aligned blocks, the counter responsible for counting how much we advanced from the start of the sg entry is overflowed because its type is u32 and we pass 4GB in size. This can lead to an infinite loop inside the iterator function because the overflow prevents the counter to be larger than the size of the sg entry. Fix the presented problem by changing the advancement condition to eliminate overflow. Backtrace: [ 192.374329] efa_reg_user_mr_dmabuf [ 192.376783] efa_register_mr [ 192.382579] pgsz_bitmap 0xfffff000 rounddown 0x80000000 [ 192.386423] pg_sz [0x80000000] umem_length[0xc0000000] [ 192.392657] start 0x0 length 0xc0000000 params.page_shift 31 params.page_num 3 [ 192.399559] hp_cnt[3], pages_in_hp[524288] [ 192.403690] umem->sgt_append.sgt.nents[1] [ 192.407905] number entries: [1], pg_bit: [31] [ 192.411397] biter->__sg_nents [1] biter->__sg [0000000008b0c5d8] [ 192.415601] biter->__sg_advance [665837568] sg_dma_len[3221225472] [ 192.419823] biter->__sg_nents [1] biter->__sg [0000000008b0c5d8] [ 192.423976] biter->__sg_advance [2813321216] sg_dma_len[3221225472] [ 192.428243] biter->__sg_nents [1] biter->__sg [0000000008b0c5d8] [ 192.432397] biter->__sg_advance [665837568] sg_dma_len[3221225472]

In the Linux kernel, the following vulnerability has been resolved: vhost: fix hung thread due to erroneous iotlb entries In vhost_iotlb_add_range_ctx(), range size can overflow to 0 when start is 0 and last is ULONG_MAX. One instance where it can happen is when userspace sends an IOTLB message with iova=size=uaddr=0 (vhost_process_iotlb_msg). So, an entry with size = 0, start = 0, last = ULONG_MAX ends up in the iotlb. Next time a packet is sent, iotlb_access_ok() loops indefinitely due to that erroneous entry. Call Trace: <TASK> iotlb_access_ok+0x21b/0x3e0 drivers/vhost/vhost.c:1340 vq_meta_prefetch+0xbc/0x280 drivers/vhost/vhost.c:1366 vhost_transport_do_send_pkt+0xe0/0xfd0 drivers/vhost/vsock.c:104 vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> Reported by syzbot at: https://syzkaller.appspot.com/bug?extid=0abd373e2e50d704db87 To fix this, do two things: 1. Return -EINVAL in vhost_chr_write_iter() when userspace asks to map a range with size 0. 2. Fix vhost_iotlb_add_range_ctx() to handle the range [0, ULONG_MAX] by splitting it into two entries.