Loop with Unreachable Exit Condition ('Infinite Loop')

A denial of service vulnerability exists in the Web Application functionality of LevelOne WBR-6012 R0.40e6. A specially crafted HTTP request can lead to a reboot. An attacker can send an HTTP request to trigger this vulnerability.Show less

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.Show less

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.Show less

In the Linux kernel, the following vulnerability has been resolved: libfs: fix infinite directory reads for offset dir After we switch tmpfs dir operations from simple_dir_operations to simple_offset_dir_operations, every rename happened will fill new dentry to dest dir's maple tree(&SHMEM_I(inode)->dir_offsets->mt) with a free key starting with octx->newx_offset, and then set newx_offset equals to free key + 1. This will lead to infinite readdir combine with rename happened at the same time, which fail generic/736 in xfstests(detail show as below). 1. create 5000 files(1 2 3...) under one dir 2. call readdir(man 3 readdir) once, and get one entry 3. rename(entry, "TEMPFILE"), then rename("TEMPFILE", entry) 4. loop 2~3, until readdir return nothing or we loop too many times(tmpfs break test with the second condition) We choose the same logic what commit 9b378f6ad48cf ("btrfs: fix infinite directory reads") to fix it, record the last_index when we open dir, and do not emit the entry which index >= last_index. The file->private_data now used in offset dir can use directly to do this, and we also update the last_index when we llseek the dir file. [brauner: only update last_index after seek when offset is zero like Jan suggested]Show less

sigstore-go, a Go library for Sigstore signing and verification, is susceptible to a denial of service attack in versions prior to 0.6.1 when a verifier is provided a maliciously crafted Sigstore Bundle containing large amounts of verifiable data, in the form of signed transparency log entries, RFC 3161 timestamps, and attestation subjects. The verification of these data structures is computationally expensive. This can be used to consume excessive CPU resources, leading to a denial of service attack. TUF's security model labels this type of vulnerability an "Endless data attack," and can lead to verification failing to complete and disrupting services that rely on sigstore-go for verification. This vulnerability is addressed with sigstore-go 0.6.1, which adds hard limits to the number of verifiable data structures that can be processed in a bundle. Verification will fail if a bundle has data that exceeds these limits. The limits are 32 signed transparency log entries, 32 RFC 3161 timestamps, 1024 attestation subjects, and 32 digests per attestation subject. These limits are intended to be high enough to accommodate the vast majority of use cases, while preventing the verification of maliciously crafted bundles that contain large amounts of verifiable data. Users who are vulnerable but unable to quickly upgrade may consider adding manual bundle validation to enforce limits similar to those in the referenced patch prior to calling sigstore-go's verification functions.Show less

HAProxy 2.9.x before 2.9.10, 3.0.x before 3.0.4, and 3.1.x through 3.1-dev6 allows a remote denial of service for HTTP/2 zero-copy forwarding (h2_send loop) under a certain set of conditions, as exploited in the wild in 2024.Show less

There is a HIGH severity vulnerability affecting the CPython "zipfile" module affecting "zipfile.Path". Note that the more common API "zipfile.ZipFile" class is unaffected. When iterating over names of entries in a zip archive (for example, methods of "zipfile.Path" like "namelist()", "iterdir()", etc) the process can be put into an infinite loop with a maliciously crafted zip archive. This defect applies when reading only metadata or extracting the contents of the zip archive. Programs that are not handling user-controlled zip archives are not affected.Show less

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!Show less

zkvyper is a Vyper compiler. Starting in version 1.3.12 and prior to version 1.5.3, since LLL IR has no Turing-incompletness restrictions, it is compiled to a loop with a much more late exit condition. It leads to a loss of funds or other unwanted behavior if the loop body contains it. However, more real-life use cases like iterating over an array are not affected. No contracts were affected by this issue, which was fixed in version 1.5.3. Upgrading and redeploying affected contracts is the only way to avoid the vulnerability.Show less

In the Linux kernel, the following vulnerability has been resolved: net, sunrpc: Remap EPERM in case of connection failure in xs_tcp_setup_socket When using a BPF program on kernel_connect(), the call can return -EPERM. This causes xs_tcp_setup_socket() to loop forever, filling up the syslog and causing the kernel to potentially freeze up. Neil suggested: This will propagate -EPERM up into other layers which might not be ready to handle it. It might be safer to map EPERM to an error we would be more likely to expect from the network system - such as ECONNREFUSED or ENETDOWN. ECONNREFUSED as error seems reasonable. For programs setting a different error can be out of reach (see handling in 4fbac77d2d09) in particular on kernels which do not have f10d05966196 ("bpf: Make BPF_PROG_RUN_ARRAY return -err instead of allow boolean"), thus given that it is better to simply remap for consistent behavior. UDP does handle EPERM in xs_udp_send_request().Show less

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. ]Show less

PDFio is a simple C library for reading and writing PDF files. There is a denial of service (DOS) vulnerability in the TTF parser. Maliciously crafted TTF files can cause the program to utilize 100% of the Memory and enter an infinite loop. This can also lead to a heap-buffer-overflow vulnerability. An infinite loop occurs in the read_camp function by nGroups value. The ttf.h library is vulnerable. A value called nGroups is extracted from the file, and by changing that value, you can cause the program to utilize 100% of the Memory and enter an infinite loop. If the value of nGroups in the file is small, an infinite loop will not occur. This library, whether used as a standalone binary or as part of another application, is vulnerable to DOS attacks when parsing certain types of files. Automated systems, including web servers that use this code to convert PDF submissions into plaintext, can be DOSed if an attacker uploads a malicious TTF file. This issue has been addressed in release version 1.3.1. All users are advised to upgrade. There are no known workarounds for this vulnerability.Show less

In the Linux kernel, the following vulnerability has been resolved: can: mcp251xfd: fix infinite loop when xmit fails When the mcp251xfd_start_xmit() function fails, the driver stops processing messages, and the interrupt routine does not return, running indefinitely even after killing the running application. Error messages: [ 441.298819] mcp251xfd spi2.0 can0: ERROR in mcp251xfd_start_xmit: -16 [ 441.306498] mcp251xfd spi2.0 can0: Transmit Event FIFO buffer not empty. (seq=0x000017c7, tef_tail=0x000017cf, tef_head=0x000017d0, tx_head=0x000017d3). ... and repeat forever. The issue can be triggered when multiple devices share the same SPI interface. And there is concurrent access to the bus. The problem occurs because tx_ring->head increments even if mcp251xfd_start_xmit() fails. Consequently, the driver skips one TX package while still expecting a response in mcp251xfd_handle_tefif_one(). Resolve the issue by starting a workqueue to write the tx obj synchronously if err = -EBUSY. In case of another error, decrement tx_ring->head, remove skb from the echo stack, and drop the message. [mkl: use more imperative wording in patch description]Show less

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.Show less

In the Linux kernel, the following vulnerability has been resolved: iavf: Fix hang during reboot/shutdown Recent commit 974578017fc1 ("iavf: Add waiting so the port is initialized in remove") adds a wait-loop at the beginning of iavf_remove() to ensure that port initialization is finished prior unregistering net device. This causes a regression in reboot/shutdown scenario because in this case callback iavf_shutdown() is called and this callback detaches the device, makes it down if it is running and sets its state to __IAVF_REMOVE. Later shutdown callback of associated PF driver (e.g. ice_shutdown) is called. That callback calls among other things sriov_disable() that calls indirectly iavf_remove() (see stack trace below). As the adapter state is already __IAVF_REMOVE then the mentioned loop is end-less and shutdown process hangs. The patch fixes this by checking adapter's state at the beginning of iavf_remove() and skips the rest of the function if the adapter is already in remove state (shutdown is in progress). Reproducer: 1. Create VF on PF driven by ice or i40e driver 2. Ensure that the VF is bound to iavf driver 3. Reboot [52625.981294] sysrq: SysRq : Show Blocked State [52625.988377] task:reboot state:D stack: 0 pid:17359 ppid: 1 f2 [52625.996732] Call Trace: [52625.999187] __schedule+0x2d1/0x830 [52626.007400] schedule+0x35/0xa0 [52626.010545] schedule_hrtimeout_range_clock+0x83/0x100 [52626.020046] usleep_range+0x5b/0x80 [52626.023540] iavf_remove+0x63/0x5b0 [iavf] [52626.027645] pci_device_remove+0x3b/0xc0 [52626.031572] device_release_driver_internal+0x103/0x1f0 [52626.036805] pci_stop_bus_device+0x72/0xa0 [52626.040904] pci_stop_and_remove_bus_device+0xe/0x20 [52626.045870] pci_iov_remove_virtfn+0xba/0x120 [52626.050232] sriov_disable+0x2f/0xe0 [52626.053813] ice_free_vfs+0x7c/0x340 [ice] [52626.057946] ice_remove+0x220/0x240 [ice] [52626.061967] ice_shutdown+0x16/0x50 [ice] [52626.065987] pci_device_shutdown+0x34/0x60 [52626.070086] device_shutdown+0x165/0x1c5 [52626.074011] kernel_restart+0xe/0x30 [52626.077593] __do_sys_reboot+0x1d2/0x210 [52626.093815] do_syscall_64+0x5b/0x1a0 [52626.097483] entry_SYSCALL_64_after_hwframe+0x65/0xcaShow less

In the Linux kernel, the following vulnerability has been resolved: net/smc: Avoid overwriting the copies of clcsock callback functions The callback functions of clcsock will be saved and replaced during the fallback. But if the fallback happens more than once, then the copies of these callback functions will be overwritten incorrectly, resulting in a loop call issue: clcsk->sk_error_report |- smc_fback_error_report() <------------------------------| |- smc_fback_forward_wakeup() | (loop) |- clcsock_callback() (incorrectly overwritten) | |- smc->clcsk_error_report() ------------------| So this patch fixes the issue by saving these function pointers only once in the fallback and avoiding overwriting.Show less