{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38106", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.985Z", "datePublished": "2025-07-03T08:35:16.215Z", "dateUpdated": "2026-08-05T11:59:34.142Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:59:34.142Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: fix use-after-free of sq->thread in __io_uring_show_fdinfo()\n\nsyzbot reports:\n\nBUG: KASAN: slab-use-after-free in getrusage+0x1109/0x1a60\nRead of size 8 at addr ffff88810de2d2c8 by task a.out/304\n\nCPU: 0 UID: 0 PID: 304 Comm: a.out Not tainted 6.16.0-rc1 #1 PREEMPT(voluntary)\nHardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\nCall Trace:\n \n dump_stack_lvl+0x53/0x70\n print_report+0xd0/0x670\n ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n ? getrusage+0x1109/0x1a60\n kasan_report+0xce/0x100\n ? getrusage+0x1109/0x1a60\n getrusage+0x1109/0x1a60\n ? __pfx_getrusage+0x10/0x10\n __io_uring_show_fdinfo+0x9fe/0x1790\n ? ksys_read+0xf7/0x1c0\n ? do_syscall_64+0xa4/0x260\n ? vsnprintf+0x591/0x1100\n ? __pfx___io_uring_show_fdinfo+0x10/0x10\n ? __pfx_vsnprintf+0x10/0x10\n ? mutex_trylock+0xcf/0x130\n ? __pfx_mutex_trylock+0x10/0x10\n ? __pfx_show_fd_locks+0x10/0x10\n ? io_uring_show_fdinfo+0x57/0x80\n io_uring_show_fdinfo+0x57/0x80\n seq_show+0x38c/0x690\n seq_read_iter+0x3f7/0x1180\n ? inode_set_ctime_current+0x160/0x4b0\n seq_read+0x271/0x3e0\n ? __pfx_seq_read+0x10/0x10\n ? __pfx__raw_spin_lock+0x10/0x10\n ? __mark_inode_dirty+0x402/0x810\n ? selinux_file_permission+0x368/0x500\n ? file_update_time+0x10f/0x160\n vfs_read+0x177/0xa40\n ? __pfx___handle_mm_fault+0x10/0x10\n ? __pfx_vfs_read+0x10/0x10\n ? mutex_lock+0x81/0xe0\n ? __pfx_mutex_lock+0x10/0x10\n ? fdget_pos+0x24d/0x4b0\n ksys_read+0xf7/0x1c0\n ? __pfx_ksys_read+0x10/0x10\n ? do_user_addr_fault+0x43b/0x9c0\n do_syscall_64+0xa4/0x260\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f0f74170fc9\nCode: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 8\nRSP: 002b:00007fffece049e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000000\nRAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0f74170fc9\nRDX: 0000000000001000 RSI: 00007fffece049f0 RDI: 0000000000000004\nRBP: 00007fffece05ad0 R08: 0000000000000000 R09: 00007fffece04d90\nR10: 0000000000000000 R11: 0000000000000206 R12: 00005651720a1100\nR13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000\n \n\nAllocated by task 298:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n __kasan_slab_alloc+0x6e/0x70\n kmem_cache_alloc_node_noprof+0xe8/0x330\n copy_process+0x376/0x5e00\n create_io_thread+0xab/0xf0\n io_sq_offload_create+0x9ed/0xf20\n io_uring_setup+0x12b0/0x1cc0\n do_syscall_64+0xa4/0x260\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nFreed by task 22:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n kasan_save_free_info+0x3b/0x60\n __kasan_slab_free+0x37/0x50\n kmem_cache_free+0xc4/0x360\n rcu_core+0x5ff/0x19f0\n handle_softirqs+0x18c/0x530\n run_ksoftirqd+0x20/0x30\n smpboot_thread_fn+0x287/0x6c0\n kthread+0x30d/0x630\n ret_from_fork+0xef/0x1a0\n ret_from_fork_asm+0x1a/0x30\n\nLast potentially related work creation:\n kasan_save_stack+0x33/0x60\n kasan_record_aux_stack+0x8c/0xa0\n __call_rcu_common.constprop.0+0x68/0x940\n __schedule+0xff2/0x2930\n __cond_resched+0x4c/0x80\n mutex_lock+0x5c/0xe0\n io_uring_del_tctx_node+0xe1/0x2b0\n io_uring_clean_tctx+0xb7/0x160\n io_uring_cancel_generic+0x34e/0x760\n do_exit+0x240/0x2350\n do_group_exit+0xab/0x220\n __x64_sys_exit_group+0x39/0x40\n x64_sys_call+0x1243/0x1840\n do_syscall_64+0xa4/0x260\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nThe buggy address belongs to the object at ffff88810de2cb00\n which belongs to the cache task_struct of size 3712\nThe buggy address is located 1992 bytes inside of\n freed 3712-byte region [ffff88810de2cb00, ffff88810de2d980)\n\nwhich is caused by the task_struct pointed to by sq->thread being\nreleased while it is being used in the function\n__io_uring_show_fdinfo(). Holding ctx->uring_lock does not prevent ehre\nrelase or exit of sq->thread.\n\nFix this by assigning and looking up ->thread under RCU, and grabbing a\nreference to the task_struct. This e\n---truncated---" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached through local syscalls only — `io_uring_setup()` to create the SQPOLL ring and `read()` on `/proc//fdinfo/`. No network or adjacent-network exposure exists for io_uring fdinfo.\nAC:L - The attacker owns both sides of the race: it creates the SQPOLL ring, decides when the SQPOLL thread exits (ring close or owner exit), and loops on fdinfo reads concurrently; the RCU-delayed `task_struct` free widens the reclaim window and a syzkaller reproducer exists.\nPR:L - Creating an `IORING_SETUP_SQPOLL` ring requires no capability (only the `security_uring_sqpoll()` LSM hook), and reading one's own `/proc/self/fdinfo/` passes the PTRACE_MODE_READ check, so any unprivileged local user qualifies.\nUI:N - The attacking process performs every step itself — ring setup, thread teardown, and the fdinfo read — with no action by any other user or victim process.\nS:U - The corruption and its consequences stay within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Use-after-free on a `task_struct` whose contents the attacker can groom via slab reuse; `getrusage()` then reads through the stale `p->signal` and thread list at controlled offsets and the harvested kernel values are printed back to userspace in the fdinfo output.\nI:H - The stale pointer drives writes — `read_seqbegin_or_lock_irqsave()` acquires the seqlock's spinlock and `get_task_mm()` performs an atomic increment through attacker-influenced pointers — giving corruption primitives suitable for escalation to control-flow hijack after heap spraying.\nA:H - Dereferencing a freed `task_struct` and walking its thread list reliably oopses or panics the kernel, and the read can be repeated in a loop by any local user." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "io_uring/fdinfo.c", "io_uring/sqpoll.c" ], "versions": [ { "version": "3fcb9d17206e31630f802a3ab52081d1342b8ed9", "lessThan": "af8c13f9ee040b9a287ba246cf0055f7c77b7cc8", "status": "affected", "versionType": "git" }, { "version": "3fcb9d17206e31630f802a3ab52081d1342b8ed9", "lessThan": "d0932758a0a77b38ba1b39564f3b7aba12407061", "status": "affected", "versionType": "git" }, { "version": "3fcb9d17206e31630f802a3ab52081d1342b8ed9", "lessThan": "ac0b8b327a5677dc6fecdf353d808161525b1ff0", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "io_uring/fdinfo.c", "io_uring/sqpoll.c" ], "versions": [ { "version": "6.9", "status": "affected" }, { "version": "0", "lessThan": "6.9", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.34", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.3", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.12.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.15.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/af8c13f9ee040b9a287ba246cf0055f7c77b7cc8" }, { "url": "https://git.kernel.org/stable/c/d0932758a0a77b38ba1b39564f3b7aba12407061" }, { "url": "https://git.kernel.org/stable/c/ac0b8b327a5677dc6fecdf353d808161525b1ff0" } ], "title": "io_uring: fix use-after-free of sq->thread in __io_uring_show_fdinfo()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2025-38106", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-06-10T20:40:20.899960Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-06-11T17:53:37.780Z" } } ] } }