Search Results (20839 CVEs found)

CVE Vendors Products Updated CVSS v3.1
CVE-2025-68310 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: s390/pci: Avoid deadlock between PCI error recovery and mlx5 crdump Do not block PCI config accesses through pci_cfg_access_lock() when executing the s390 variant of PCI error recovery: Acquire just device_lock() instead of pci_dev_lock() as powerpc's EEH and generig PCI AER processing do. During error recovery testing a pair of tasks was reported to be hung: mlx5_core 0000:00:00.1: mlx5_health_try_recover:338:(pid 5553): health recovery flow aborted, PCI reads still not working INFO: task kmcheck:72 blocked for more than 122 seconds. Not tainted 5.14.0-570.12.1.bringup7.el9.s390x #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kmcheck state:D stack:0 pid:72 tgid:72 ppid:2 flags:0x00000000 Call Trace: [<000000065256f030>] __schedule+0x2a0/0x590 [<000000065256f356>] schedule+0x36/0xe0 [<000000065256f572>] schedule_preempt_disabled+0x22/0x30 [<0000000652570a94>] __mutex_lock.constprop.0+0x484/0x8a8 [<000003ff800673a4>] mlx5_unload_one+0x34/0x58 [mlx5_core] [<000003ff8006745c>] mlx5_pci_err_detected+0x94/0x140 [mlx5_core] [<0000000652556c5a>] zpci_event_attempt_error_recovery+0xf2/0x398 [<0000000651b9184a>] __zpci_event_error+0x23a/0x2c0 INFO: task kworker/u1664:6:1514 blocked for more than 122 seconds. Not tainted 5.14.0-570.12.1.bringup7.el9.s390x #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u1664:6 state:D stack:0 pid:1514 tgid:1514 ppid:2 flags:0x00000000 Workqueue: mlx5_health0000:00:00.0 mlx5_fw_fatal_reporter_err_work [mlx5_core] Call Trace: [<000000065256f030>] __schedule+0x2a0/0x590 [<000000065256f356>] schedule+0x36/0xe0 [<0000000652172e28>] pci_wait_cfg+0x80/0xe8 [<0000000652172f94>] pci_cfg_access_lock+0x74/0x88 [<000003ff800916b6>] mlx5_vsc_gw_lock+0x36/0x178 [mlx5_core] [<000003ff80098824>] mlx5_crdump_collect+0x34/0x1c8 [mlx5_core] [<000003ff80074b62>] mlx5_fw_fatal_reporter_dump+0x6a/0xe8 [mlx5_core] [<0000000652512242>] devlink_health_do_dump.part.0+0x82/0x168 [<0000000652513212>] devlink_health_report+0x19a/0x230 [<000003ff80075a12>] mlx5_fw_fatal_reporter_err_work+0xba/0x1b0 [mlx5_core] No kernel log of the exact same error with an upstream kernel is available - but the very same deadlock situation can be constructed there, too: - task: kmcheck mlx5_unload_one() tries to acquire devlink lock while the PCI error recovery code has set pdev->block_cfg_access by way of pci_cfg_access_lock() - task: kworker mlx5_crdump_collect() tries to set block_cfg_access through pci_cfg_access_lock() while devlink_health_report() had acquired the devlink lock. A similar deadlock situation can be reproduced by requesting a crdump with > devlink health dump show pci/<BDF> reporter fw_fatal while PCI error recovery is executed on the same <BDF> physical function by mlx5_core's pci_error_handlers. On s390 this can be injected with > zpcictl --reset-fw <BDF> Tests with this patch failed to reproduce that second deadlock situation, the devlink command is rejected with "kernel answers: Permission denied" - and we get a kernel log message of: mlx5_core 1ed0:00:00.1: mlx5_crdump_collect:50:(pid 254382): crdump: failed to lock vsc gw err -5 because the config read of VSC_SEMAPHORE is rejected by the underlying hardware. Two prior attempts to address this issue have been discussed and ultimately rejected [see link], with the primary argument that s390's implementation of PCI error recovery is imposing restrictions that neither powerpc's EEH nor PCI AER handling need. Tests show that PCI error recovery on s390 is running to completion even without blocking access to PCI config space.
CVE-2025-68220 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: net: ethernet: ti: netcp: Standardize knav_dma_open_channel to return NULL on error Make knav_dma_open_channel consistently return NULL on error instead of ERR_PTR. Currently the header include/linux/soc/ti/knav_dma.h returns NULL when the driver is disabled, but the driver implementation does not even return NULL or ERR_PTR on failure, causing inconsistency in the users. This results in a crash in netcp_free_navigator_resources as followed (trimmed): Unhandled fault: alignment exception (0x221) at 0xfffffff2 [fffffff2] *pgd=80000800207003, *pmd=82ffda003, *pte=00000000 Internal error: : 221 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.17.0-rc7 #1 NONE Hardware name: Keystone PC is at knav_dma_close_channel+0x30/0x19c LR is at netcp_free_navigator_resources+0x2c/0x28c [... TRIM...] Call trace: knav_dma_close_channel from netcp_free_navigator_resources+0x2c/0x28c netcp_free_navigator_resources from netcp_ndo_open+0x430/0x46c netcp_ndo_open from __dev_open+0x114/0x29c __dev_open from __dev_change_flags+0x190/0x208 __dev_change_flags from netif_change_flags+0x1c/0x58 netif_change_flags from dev_change_flags+0x38/0xa0 dev_change_flags from ip_auto_config+0x2c4/0x11f0 ip_auto_config from do_one_initcall+0x58/0x200 do_one_initcall from kernel_init_freeable+0x1cc/0x238 kernel_init_freeable from kernel_init+0x1c/0x12c kernel_init from ret_from_fork+0x14/0x38 [... TRIM...] Standardize the error handling by making the function return NULL on all error conditions. The API is used in just the netcp_core.c so the impact is limited. Note, this change, in effect reverts commit 5b6cb43b4d62 ("net: ethernet: ti: netcp_core: return error while dma channel open issue"), but provides a less error prone implementation.
CVE-2025-68313 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: x86/CPU/AMD: Add RDSEED fix for Zen5 There's an issue with RDSEED's 16-bit and 32-bit register output variants on Zen5 which return a random value of 0 "at a rate inconsistent with randomness while incorrectly signaling success (CF=1)". Search the web for AMD-SB-7055 for more detail. Add a fix glue which checks microcode revisions. [ bp: Add microcode revisions checking, rewrite. ]
CVE-2025-68314 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: drm/msm: make sure last_fence is always updated Update last_fence in the vm-bind path instead of kernel managed path. last_fence is used to wait for work to finish in vm_bind contexts but not used for kernel managed contexts. This fixes a bug where last_fence is not waited on context close leading to faults as resources are freed while in use. Patchwork: https://patchwork.freedesktop.org/patch/680080/
CVE-2025-68316 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Fix invalid probe error return value After DME Link Startup, the error return value is set to the MIPI UniPro GenericErrorCode which can be 0 (SUCCESS) or 1 (FAILURE). Upon failure during driver probe, the error code 1 is propagated back to the driver probe function which must return a negative value to indicate an error, but 1 is not negative, so the probe is considered to be successful even though it failed. Subsequently, removing the driver results in an oops because it is not in a valid state. This happens because none of the callers of ufshcd_init() expect a non-negative error code. Fix the return value and documentation to match actual usage.
CVE-2025-68219 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: cifs: fix memory leak in smb3_fs_context_parse_param error path Add proper cleanup of ctx->source and fc->source to the cifs_parse_mount_err error handler. This ensures that memory allocated for the source strings is correctly freed on all error paths, matching the cleanup already performed in the success path by smb3_cleanup_fs_context_contents(). Pointers are also set to NULL after freeing to prevent potential double-free issues. This change fixes a memory leak originally detected by syzbot. The leak occurred when processing Opt_source mount options if an error happened after ctx->source and fc->source were successfully allocated but before the function completed. The specific leak sequence was: 1. ctx->source = smb3_fs_context_fullpath(ctx, '/') allocates memory 2. fc->source = kstrdup(ctx->source, GFP_KERNEL) allocates more memory 3. A subsequent error jumps to cifs_parse_mount_err 4. The old error handler freed passwords but not the source strings, causing the memory to leak. This issue was not addressed by commit e8c73eb7db0a ("cifs: client: fix memory leak in smb3_fs_context_parse_param"), which only fixed leaks from repeated fsconfig() calls but not this error path. Patch updated with minor change suggested by kernel test robot
CVE-2025-68218 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: nvme-multipath: fix lockdep WARN due to partition scan work Blktests test cases nvme/014, 057 and 058 fail occasionally due to a lockdep WARN. As reported in the Closes tag URL, the WARN indicates that a deadlock can happen due to the dependency among disk->open_mutex, kblockd workqueue completion and partition_scan_work completion. To avoid the lockdep WARN and the potential deadlock, cut the dependency by running the partition_scan_work not by kblockd workqueue but by nvme_wq.
CVE-2025-68217 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: Input: pegasus-notetaker - fix potential out-of-bounds access In the pegasus_notetaker driver, the pegasus_probe() function allocates the URB transfer buffer using the wMaxPacketSize value from the endpoint descriptor. An attacker can use a malicious USB descriptor to force the allocation of a very small buffer. Subsequently, if the device sends an interrupt packet with a specific pattern (e.g., where the first byte is 0x80 or 0x42), the pegasus_parse_packet() function parses the packet without checking the allocated buffer size. This leads to an out-of-bounds memory access.
CVE-2025-68216 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: LoongArch: BPF: Disable trampoline for kernel module function trace The current LoongArch BPF trampoline implementation is incompatible with tracing functions in kernel modules. This causes several severe and user-visible problems: * The `bpf_selftests/module_attach` test fails consistently. * Kernel lockup when a BPF program is attached to a module function [1]. * Critical kernel modules like WireGuard experience traffic disruption when their functions are traced with fentry [2]. Given the severity and the potential for other unknown side-effects, it is safest to disable the feature entirely for now. This patch prevents the BPF subsystem from allowing trampoline attachments to kernel module functions on LoongArch. This is a temporary mitigation until the core issues in the trampoline code for kernel module handling can be identified and fixed. [root@fedora bpf]# ./test_progs -a module_attach -v bpf_testmod.ko is already unloaded. Loading bpf_testmod.ko... Successfully loaded bpf_testmod.ko. test_module_attach:PASS:skel_open 0 nsec test_module_attach:PASS:set_attach_target 0 nsec test_module_attach:PASS:set_attach_target_explicit 0 nsec test_module_attach:PASS:skel_load 0 nsec libbpf: prog 'handle_fentry': failed to attach: -ENOTSUPP libbpf: prog 'handle_fentry': failed to auto-attach: -ENOTSUPP test_module_attach:FAIL:skel_attach skeleton attach failed: -524 Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED Successfully unloaded bpf_testmod.ko. [1]: https://lore.kernel.org/loongarch/CAK3+h2wDmpC-hP4u4pJY8T-yfKyk4yRzpu2LMO+C13FMT58oqQ@mail.gmail.com/ [2]: https://lore.kernel.org/loongarch/CAK3+h2wYcpc+OwdLDUBvg2rF9rvvyc5amfHT-KcFaK93uoELPg@mail.gmail.com/
CVE-2025-68317 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: io_uring/zctx: check chained notif contexts Send zc only links ubuf_info for requests coming from the same context. There are some ambiguous syz reports, so let's check the assumption on notification completion.
CVE-2025-68215 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: ice: fix PTP cleanup on driver removal in error path Improve the cleanup on releasing PTP resources in error path. The error case might happen either at the driver probe and PTP feature initialization or on PTP restart (errors in reset handling, NVM update etc). In both cases, calls to PF PTP cleanup (ice_ptp_cleanup_pf function) and 'ps_lock' mutex deinitialization were missed. Additionally, ptp clock was not unregistered in the latter case. Keep PTP state as 'uninitialized' on init to distinguish between error scenarios and to avoid resource release duplication at driver removal. The consequence of missing ice_ptp_cleanup_pf call is the following call trace dumped when ice_adapter object is freed (port list is not empty, as it is required at this stage): [ T93022] ------------[ cut here ]------------ [ T93022] WARNING: CPU: 10 PID: 93022 at ice/ice_adapter.c:67 ice_adapter_put+0xef/0x100 [ice] ... [ T93022] RIP: 0010:ice_adapter_put+0xef/0x100 [ice] ... [ T93022] Call Trace: [ T93022] <TASK> [ T93022] ? ice_adapter_put+0xef/0x100 [ice 33d2647ad4f6d866d41eefff1806df37c68aef0c] [ T93022] ? __warn.cold+0xb0/0x10e [ T93022] ? ice_adapter_put+0xef/0x100 [ice 33d2647ad4f6d866d41eefff1806df37c68aef0c] [ T93022] ? report_bug+0xd8/0x150 [ T93022] ? handle_bug+0xe9/0x110 [ T93022] ? exc_invalid_op+0x17/0x70 [ T93022] ? asm_exc_invalid_op+0x1a/0x20 [ T93022] ? ice_adapter_put+0xef/0x100 [ice 33d2647ad4f6d866d41eefff1806df37c68aef0c] [ T93022] pci_device_remove+0x42/0xb0 [ T93022] device_release_driver_internal+0x19f/0x200 [ T93022] driver_detach+0x48/0x90 [ T93022] bus_remove_driver+0x70/0xf0 [ T93022] pci_unregister_driver+0x42/0xb0 [ T93022] ice_module_exit+0x10/0xdb0 [ice 33d2647ad4f6d866d41eefff1806df37c68aef0c] ... [ T93022] ---[ end trace 0000000000000000 ]--- [ T93022] ice: module unloaded
CVE-2025-68213 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: idpf: fix possible vport_config NULL pointer deref in remove Attempting to remove the driver will cause a crash in cases where the vport failed to initialize. Following trace is from an instance where the driver failed during an attempt to create a VF: [ 1661.543624] idpf 0000:84:00.7: Device HW Reset initiated [ 1722.923726] idpf 0000:84:00.7: Transaction timed-out (op:1 cookie:2900 vc_op:1 salt:29 timeout:60000ms) [ 1723.353263] BUG: kernel NULL pointer dereference, address: 0000000000000028 ... [ 1723.358472] RIP: 0010:idpf_remove+0x11c/0x200 [idpf] ... [ 1723.364973] Call Trace: [ 1723.365475] <TASK> [ 1723.365972] pci_device_remove+0x42/0xb0 [ 1723.366481] device_release_driver_internal+0x1a9/0x210 [ 1723.366987] pci_stop_bus_device+0x6d/0x90 [ 1723.367488] pci_stop_and_remove_bus_device+0x12/0x20 [ 1723.367971] pci_iov_remove_virtfn+0xbd/0x120 [ 1723.368309] sriov_disable+0x34/0xe0 [ 1723.368643] idpf_sriov_configure+0x58/0x140 [idpf] [ 1723.368982] sriov_numvfs_store+0xda/0x1c0 Avoid the NULL pointer dereference by adding NULL pointer check for vport_config[i], before freeing user_config.q_coalesce.
CVE-2025-68319 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: netconsole: Acquire su_mutex before navigating configs hierarchy There is a race between operations that iterate over the userdata cg_children list and concurrent add/remove of userdata items through configfs. The update_userdata() function iterates over the nt->userdata_group.cg_children list, and count_extradata_entries() also iterates over this same list to count nodes. Quoting from Documentation/filesystems/configfs.rst: > A subsystem can navigate the cg_children list and the ci_parent pointer > to see the tree created by the subsystem. This can race with configfs' > management of the hierarchy, so configfs uses the subsystem mutex to > protect modifications. Whenever a subsystem wants to navigate the > hierarchy, it must do so under the protection of the subsystem > mutex. Without proper locking, if a userdata item is added or removed concurrently while these functions are iterating, the list can be accessed in an inconsistent state. For example, the list_for_each() loop can reach a node that is being removed from the list by list_del_init() which sets the nodes' .next pointer to point to itself, so the loop will never end (or reach the WARN_ON_ONCE in update_userdata() ). Fix this by holding the configfs subsystem mutex (su_mutex) during all operations that iterate over cg_children. This includes: - userdatum_value_store() which calls update_userdata() to iterate over cg_children - All sysdata_*_enabled_store() functions which call count_extradata_entries() to iterate over cg_children The su_mutex must be acquired before dynamic_netconsole_mutex to avoid potential lock ordering issues, as configfs operations may already hold su_mutex when calling into our code.
CVE-2025-68320 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: lan966x: Fix sleeping in atomic context The following warning was seen when we try to connect using ssh to the device. BUG: sleeping function called from invalid context at kernel/locking/mutex.c:575 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 104, name: dropbear preempt_count: 1, expected: 0 INFO: lockdep is turned off. CPU: 0 UID: 0 PID: 104 Comm: dropbear Tainted: G W 6.18.0-rc2-00399-g6f1ab1b109b9-dirty #530 NONE Tainted: [W]=WARN Hardware name: Generic DT based system Call trace: unwind_backtrace from show_stack+0x10/0x14 show_stack from dump_stack_lvl+0x7c/0xac dump_stack_lvl from __might_resched+0x16c/0x2b0 __might_resched from __mutex_lock+0x64/0xd34 __mutex_lock from mutex_lock_nested+0x1c/0x24 mutex_lock_nested from lan966x_stats_get+0x5c/0x558 lan966x_stats_get from dev_get_stats+0x40/0x43c dev_get_stats from dev_seq_printf_stats+0x3c/0x184 dev_seq_printf_stats from dev_seq_show+0x10/0x30 dev_seq_show from seq_read_iter+0x350/0x4ec seq_read_iter from seq_read+0xfc/0x194 seq_read from proc_reg_read+0xac/0x100 proc_reg_read from vfs_read+0xb0/0x2b0 vfs_read from ksys_read+0x6c/0xec ksys_read from ret_fast_syscall+0x0/0x1c Exception stack(0xf0b11fa8 to 0xf0b11ff0) 1fa0: 00000001 00001000 00000008 be9048d8 00001000 00000001 1fc0: 00000001 00001000 00000008 00000003 be905920 0000001e 00000000 00000001 1fe0: 0005404c be9048c0 00018684 b6ec2cd8 It seems that we are using a mutex in a atomic context which is wrong. Change the mutex with a spinlock.
CVE-2025-68322 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: parisc: Avoid crash due to unaligned access in unwinder Guenter Roeck reported this kernel crash on his emulated B160L machine: Starting network: udhcpc: started, v1.36.1 Backtrace: [<104320d4>] unwind_once+0x1c/0x5c [<10434a00>] walk_stackframe.isra.0+0x74/0xb8 [<10434a6c>] arch_stack_walk+0x28/0x38 [<104e5efc>] stack_trace_save+0x48/0x5c [<105d1bdc>] set_track_prepare+0x44/0x6c [<105d9c80>] ___slab_alloc+0xfc4/0x1024 [<105d9d38>] __slab_alloc.isra.0+0x58/0x90 [<105dc80c>] kmem_cache_alloc_noprof+0x2ac/0x4a0 [<105b8e54>] __anon_vma_prepare+0x60/0x280 [<105a823c>] __vmf_anon_prepare+0x68/0x94 [<105a8b34>] do_wp_page+0x8cc/0xf10 [<105aad88>] handle_mm_fault+0x6c0/0xf08 [<10425568>] do_page_fault+0x110/0x440 [<10427938>] handle_interruption+0x184/0x748 [<11178398>] schedule+0x4c/0x190 BUG: spinlock recursion on CPU#0, ifconfig/2420 lock: terminate_lock.2+0x0/0x1c, .magic: dead4ead, .owner: ifconfig/2420, .owner_cpu: 0 While creating the stack trace, the unwinder uses the stack pointer to guess the previous frame to read the previous stack pointer from memory. The crash happens, because the unwinder tries to read from unaligned memory and as such triggers the unalignment trap handler which then leads to the spinlock recursion and finally to a deadlock. Fix it by checking the alignment before accessing the memory.
CVE-2025-68212 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: fs: Fix uninitialized 'offp' in statmount_string() In statmount_string(), most flags assign an output offset pointer (offp) which is later updated with the string offset. However, the STATMOUNT_MNT_UIDMAP and STATMOUNT_MNT_GIDMAP cases directly set the struct fields instead of using offp. This leaves offp uninitialized, leading to a possible uninitialized dereference when *offp is updated. Fix it by assigning offp for UIDMAP and GIDMAP as well, keeping the code path consistent.
CVE-2025-68210 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: erofs: avoid infinite loop due to incomplete zstd-compressed data Currently, the decompression logic incorrectly spins if compressed data is truncated in crafted (deliberately corrupted) images.
CVE-2025-68209 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: mlx5: Fix default values in create CQ Currently, CQs without a completion function are assigned the mlx5_add_cq_to_tasklet function by default. This is problematic since only user CQs created through the mlx5_ib driver are intended to use this function. Additionally, all CQs that will use doorbells instead of polling for completions must call mlx5_cq_arm. However, the default CQ creation flow leaves a valid value in the CQ's arm_db field, allowing FW to send interrupts to polling-only CQs in certain corner cases. These two factors would allow a polling-only kernel CQ to be triggered by an EQ interrupt and call a completion function intended only for user CQs, causing a null pointer exception. Some areas in the driver have prevented this issue with one-off fixes but did not address the root cause. This patch fixes the described issue by adding defaults to the create CQ flow. It adds a default dummy completion function to protect against null pointer exceptions, and it sets an invalid command sequence number by default in kernel CQs to prevent the FW from sending an interrupt to the CQ until it is armed. User CQs are responsible for their own initialization values. Callers of mlx5_core_create_cq are responsible for changing the completion function and arming the CQ per their needs.
CVE-2023-53861 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: ext4: correct grp validation in ext4_mb_good_group Group corruption check will access memory of grp and will trigger kernel crash if grp is NULL. So do NULL check before corruption check.
CVE-2025-68208 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: bpf: account for current allocated stack depth in widen_imprecise_scalars() The usage pattern for widen_imprecise_scalars() looks as follows: prev_st = find_prev_entry(env, ...); queued_st = push_stack(...); widen_imprecise_scalars(env, prev_st, queued_st); Where prev_st is an ancestor of the queued_st in the explored states tree. This ancestor is not guaranteed to have same allocated stack depth as queued_st. E.g. in the following case: def main(): for i in 1..2: foo(i) // same callsite, differnt param def foo(i): if i == 1: use 128 bytes of stack iterator based loop Here, for a second 'foo' call prev_st->allocated_stack is 128, while queued_st->allocated_stack is much smaller. widen_imprecise_scalars() needs to take this into account and avoid accessing bpf_verifier_state->frame[*]->stack out of bounds.