CVE-2022-50323

Published Sep 15, 2025

Last updated a year ago

CVSS medium 5.5

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: net: do not sense pfmemalloc status in skb_append_pagefrags() skb_append_pagefrags() is used by af_unix and udp sendpage() implementation so far. In commit 326140063946 ("tcp: TX zerocopy should not sense pfmemalloc status") we explained why we should not sense pfmemalloc status for pages owned by user space. We should also use skb_fill_page_desc_noacc() in skb_append_pagefrags() to avoid following KCSAN report: BUG: KCSAN: data-race in lru_add_fn / skb_append_pagefrags write to 0xffffea00058fc1c8 of 8 bytes by task 17319 on cpu 0: __list_add include/linux/list.h:73 [inline] list_add include/linux/list.h:88 [inline] lruvec_add_folio include/linux/mm_inline.h:323 [inline] lru_add_fn+0x327/0x410 mm/swap.c:228 folio_batch_move_lru+0x1e1/0x2a0 mm/swap.c:246 lru_add_drain_cpu+0x73/0x250 mm/swap.c:669 lru_add_drain+0x21/0x60 mm/swap.c:773 free_pages_and_swap_cache+0x16/0x70 mm/swap_state.c:311 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:256 [inline] tlb_flush_mmu+0x5b2/0x640 mm/mmu_gather.c:263 tlb_finish_mmu+0x86/0x100 mm/mmu_gather.c:363 exit_mmap+0x190/0x4d0 mm/mmap.c:3098 __mmput+0x27/0x1b0 kernel/fork.c:1185 mmput+0x3d/0x50 kernel/fork.c:1207 copy_process+0x19fc/0x2100 kernel/fork.c:2518 kernel_clone+0x166/0x550 kernel/fork.c:2671 __do_sys_clone kernel/fork.c:2812 [inline] __se_sys_clone kernel/fork.c:2796 [inline] __x64_sys_clone+0xc3/0xf0 kernel/fork.c:2796 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffffea00058fc1c8 of 8 bytes by task 17325 on cpu 1: page_is_pfmemalloc include/linux/mm.h:1817 [inline] __skb_fill_page_desc include/linux/skbuff.h:2432 [inline] skb_fill_page_desc include/linux/skbuff.h:2453 [inline] skb_append_pagefrags+0x210/0x600 net/core/skbuff.c:3974 unix_stream_sendpage+0x45e/0x990 net/unix/af_unix.c:2338 kernel_sendpage+0x184/0x300 net/socket.c:3561 sock_sendpage+0x5a/0x70 net/socket.c:1054 pipe_to_sendpage+0x128/0x160 fs/splice.c:361 splice_from_pipe_feed fs/splice.c:415 [inline] __splice_from_pipe+0x222/0x4d0 fs/splice.c:559 splice_from_pipe fs/splice.c:594 [inline] generic_splice_sendpage+0x89/0xc0 fs/splice.c:743 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:931 splice_direct_to_actor+0x305/0x620 fs/splice.c:886 do_splice_direct+0xfb/0x180 fs/splice.c:974 do_sendfile+0x3bf/0x910 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x0000000000000000 -> 0xffffea00058fc188 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 17325 Comm: syz-executor.0 Not tainted 6.1.0-rc1-syzkaller-00158-g440b7895c990-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
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
NVD-CWE-noinfo

Social media

Hype score
Not currently trending

Configurations

Related CVEs

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  2. 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
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  4. In the Linux kernel, the following vulnerability has been resolved: nvdimm: pmem: keep PREFLUSH before data writes pmem_submit_bio() records a REQ_PREFLUSH error, but continues to copy the bio data and can later overwrite the error with a successful REQ_FUA flush. That lets data writes run after a failed preflush and can complete the bio successfully despite the failed ordering barrier. Run the REQ_PREFLUSH flush synchronously before touching the bio data and complete the bio with the flush error if it fails. Keep asynchronous flush chaining for REQ_FUA. At that point, data copy has completed and the parent bio can wait for the chained flush bio.•CVE-2026-98161
  5. In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix mismatched free of HalData in rtw_sdio_if1_init() padapter->HalData is allocated via vzalloc(), but incorrectly freed using kfree() in the rtw_sdio_if1_init() error path. Using kfree() to release this vmalloc-backed buffer can lead to memory corruption. Use rtw_hal_data_deinit() to pair the free correctly and free HalData with vfree(). The bug was first flagged by an experimental static analysis tool we are developing for kernel memory-management bugs. Manual inspection confirms that the issue is still present in current mainline. An x86_64 allyesconfig build showed no new warnings. As we do not have suitable RTL8723BS SDIO hardware to test with, no runtime testing was able to be performed.•CVE-2026-98160

References

Sources include official advisories and independent security research.