CVE-2026-43413

Published May 8, 2026

Last updated 5 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: scsi: hisi_sas: Fix NULL pointer exception during user_scan() user_scan() invokes updated sas_user_scan() for channel 0, and if successful, iteratively scans remaining channels (1 to shost->max_channel) via scsi_scan_host_selected() in commit 37c4e72b0651 ("scsi: Fix sas_user_scan() to handle wildcard and multi-channel scans"). However, hisi_sas supports only one channel, and the current value of max_channel is 1. sas_user_scan() for channel 1 will trigger the following NULL pointer exception: [ 441.554662] Unable to handle kernel NULL pointer dereference at virtual address 00000000000008b0 [ 441.554699] Mem abort info: [ 441.554710] ESR = 0x0000000096000004 [ 441.554718] EC = 0x25: DABT (current EL), IL = 32 bits [ 441.554723] SET = 0, FnV = 0 [ 441.554726] EA = 0, S1PTW = 0 [ 441.554730] FSC = 0x04: level 0 translation fault [ 441.554735] Data abort info: [ 441.554737] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 441.554742] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 441.554747] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 441.554752] user pgtable: 4k pages, 48-bit VAs, pgdp=00000828377a6000 [ 441.554757] [00000000000008b0] pgd=0000000000000000, p4d=0000000000000000 [ 441.554769] Internal error: Oops: 0000000096000004 [#1] SMP [ 441.629589] Modules linked in: arm_spe_pmu arm_smmuv3_pmu tpm_tis_spi hisi_uncore_sllc_pmu hisi_uncore_pa_pmu hisi_uncore_l3c_pmu hisi_uncore_hha_pmu hisi_uncore_ddrc_pmu hisi_uncore_cpa_pmu hns3_pmu hisi_ptt hisi_pcie_pmu tpm_tis_core spidev spi_hisi_sfc_v3xx hisi_uncore_pmu spi_dw_mmio fuse hclge hclge_common hisi_sec2 hisi_hpre hisi_zip hisi_qm hns3 hisi_sas_v3_hw sm3_ce sbsa_gwdt hnae3 hisi_sas_main uacce hisi_dma i2c_hisi dm_mirror dm_region_hash dm_log dm_mod [ 441.670819] CPU: 46 UID: 0 PID: 6994 Comm: bash Kdump: loaded Not tainted 7.0.0-rc2+ #84 PREEMPT [ 441.691327] pstate: 81400009 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 441.698277] pc : sas_find_dev_by_rphy+0x44/0x118 [ 441.702896] lr : sas_find_dev_by_rphy+0x3c/0x118 [ 441.707502] sp : ffff80009abbba40 [ 441.710805] x29: ffff80009abbba40 x28: ffff082819a40008 x27: ffff082810c37c08 [ 441.717930] x26: ffff082810c37c28 x25: ffff082819a40290 x24: ffff082810c37c00 [ 441.725054] x23: 0000000000000000 x22: 0000000000000001 x21: ffff082819a40000 [ 441.732179] x20: ffff082819a40290 x19: 0000000000000000 x18: 0000000000000020 [ 441.739304] x17: 0000000000000000 x16: ffffb5dad6bda690 x15: 00000000ffffffff [ 441.746428] x14: ffff082814c3b26c x13: 00000000ffffffff x12: ffff082814c3b26a [ 441.753553] x11: 00000000000000c0 x10: 000000000000003a x9 : ffffb5dad5ea94f4 [ 441.760678] x8 : 000000000000003a x7 : ffff80009abbbab0 x6 : 0000000000000030 [ 441.767802] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000 [ 441.774926] x2 : ffff08280f35a300 x1 : ffffb5dad7127180 x0 : 0000000000000000 [ 441.782053] Call trace: [ 441.784488] sas_find_dev_by_rphy+0x44/0x118 (P) [ 441.789095] sas_target_alloc+0x24/0xb0 [ 441.792920] scsi_alloc_target+0x290/0x330 [ 441.797010] __scsi_scan_target+0x88/0x258 [ 441.801096] scsi_scan_channel+0x74/0xb8 [ 441.805008] scsi_scan_host_selected+0x170/0x188 [ 441.809615] sas_user_scan+0xfc/0x148 [ 441.813267] store_scan+0x10c/0x180 [ 441.816743] dev_attr_store+0x20/0x40 [ 441.820398] sysfs_kf_write+0x84/0xa8 [ 441.824054] kernfs_fop_write_iter+0x130/0x1c8 [ 441.828487] vfs_write+0x2c0/0x370 [ 441.831880] ksys_write+0x74/0x118 [ 441.835271] __arm64_sys_write+0x24/0x38 [ 441.839182] invoke_syscall+0x50/0x120 [ 441.842919] el0_svc_common.constprop.0+0xc8/0xf0 [ 441.847611] do_el0_svc+0x24/0x38 [ 441.850913] el0_svc+0x38/0x158 [ 441.854043] el0t_64_sync_handler+0xa0/0xe8 [ 441.858214] el0t_64_sync+0x1ac/0x1b0 [ 441.861865] Code: aa1303e0 97ff70a8 34ffff80 d10a4273 (f9445a75) [ 441.867946] ---[ end trace 0000000000000000 ]--- Therefore ---truncated---
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
CWE-476

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: cgroup: Avoid iteration of dying tasks with zero refcount The commit 260fbcb92bbea ("cgroup: Move dying_tasks cleanup from cgroup_task_release() to cgroup_task_free()") extended the lifetime of tasks on the dying_tasks list. The iterators have provision to go through dying_tasks because of dying threadgroup leaders or explicit CSS_TASK_ITER_WITH_DEAD, however, it was expected that such tasks can obtain a new reference (that is possible before cgroup_task_release()/put_task_struct_rcu_user()). The tasks after cgroup_task_release() and before cgroup_task_free() are subject to race when they may or may not have ->usage count > 0. The race window is between css_task_iter_next() invocations when css_set_lock is released and we may arrive at a new ->task_pos. The iterator should not attempt to resurrect tasks whose ->usage count dropped to zero. (When that happens, __put_task_struct_rcu_cb() is already imminent and the returned task_struct would could be used after free.) As for the fix, we cannot simply check the signal->live count of a task on the dying list because that won't distinguish regular zombies waiting to be reaped from RCU remnant tasks that are going to be free'd. Therefore add an extra check to rule out ->usage==0 tasks from any iteration. The repeat: loop in css_task_iter_advance() doesn't consider ->usage count, so add a new loop to css_task_iter_next() to skip de-used tasks on the dying_list. Rough illustration of the possible race R (reader of cgroup.procs) T (thread) L (group leader) --------------------------------- -------------------------------- -------------------------------- L exits, signal->live > 0 cgroup_task_dead(L) css_set_skip_task_iters() // skips only cset->tasks list_add_tail(&L->cg_list, &cset->dying_tasks) css_task_iter_next() take css_set_lock css_task_iter_advance() leader && signal->live != 0 => it->task_pos = &L->cg_list release css_set_lock T exits --signal->live == 0 cgroup_task_dead(T) // css_set_lock release_task(T) cgroup_task_release(T) release_task(L) // zap_leader cgroup_task_release(L) put_task_struct_rcu_user(L) ...RCU... put_task_struct(L) L->usage = 0 /* L still on dying_tasks */ ...RCU... __put_task_struct(L) css_task_iter_next() // another iteration take css_set_lock it->task_pos = &L->cg_list get_task_struct(L) => addition on 0 drop css_set_lock cgroup_task_free(L) css_set_skip_task_iters() // dying skip comes too late free_task(L) cgroup_procs_show() task_pid_vnr(L)•CVE-2026-98163