{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2022-49783", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-05-01T14:05:17.223Z", "datePublished": "2025-05-01T14:09:17.054Z", "dateUpdated": "2025-05-04T08:45:16.690Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-05-04T08:45:16.690Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/fpu: Drop fpregs lock before inheriting FPU permissions\n\nMike Galbraith reported the following against an old fork of preempt-rt\nbut the same issue also applies to the current preempt-rt tree.\n\n BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46\n in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: systemd\n preempt_count: 1, expected: 0\n RCU nest depth: 0, expected: 0\n Preemption disabled at:\n fpu_clone\n CPU: 6 PID: 1 Comm: systemd Tainted: G E (unreleased)\n Call Trace:\n <TASK>\n dump_stack_lvl\n ? fpu_clone\n __might_resched\n rt_spin_lock\n fpu_clone\n ? copy_thread\n ? copy_process\n ? shmem_alloc_inode\n ? kmem_cache_alloc\n ? kernel_clone\n ? __do_sys_clone\n ? do_syscall_64\n ? __x64_sys_rt_sigprocmask\n ? syscall_exit_to_user_mode\n ? do_syscall_64\n ? syscall_exit_to_user_mode\n ? do_syscall_64\n ? syscall_exit_to_user_mode\n ? do_syscall_64\n ? exc_page_fault\n ? entry_SYSCALL_64_after_hwframe\n </TASK>\n\nMike says:\n\n The splat comes from fpu_inherit_perms() being called under fpregs_lock(),\n and us reaching the spin_lock_irq() therein due to fpu_state_size_dynamic()\n returning true despite static key __fpu_state_size_dynamic having never\n been enabled.\n\nMike's assessment looks correct. fpregs_lock on a PREEMPT_RT kernel disables\npreemption so calling spin_lock_irq() in fpu_inherit_perms() is unsafe. This\nproblem exists since commit\n\n 9e798e9aa14c (\"x86/fpu: Prepare fpu_clone() for dynamically enabled features\").\n\nEven though the original bug report should not have enabled the paths at\nall, the bug still exists.\n\nfpregs_lock is necessary when editing the FPU registers or a task's FP\nstate but it is not necessary for fpu_inherit_perms(). The only write\nof any FP state in fpu_inherit_perms() is for the new child which is\nnot running yet and cannot context switch or be borrowed by a kernel\nthread yet. Hence, fpregs_lock is not protecting anything in the new\nchild until clone() completes and can be dropped earlier. The siglock\nstill needs to be acquired by fpu_inherit_perms() as the read of the\nparent's permissions has to be serialised.\n\n [ bp: Cleanup splat. ]"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kernel/fpu/core.c"], "versions": [{"version": "9e798e9aa14c45fb94e47b30bf6347b369ce9df7", "lessThan": "c6e8a7a1780af3da65e78a615f7d0874da6aabb0", "status": "affected", "versionType": "git"}, {"version": "9e798e9aa14c45fb94e47b30bf6347b369ce9df7", "lessThan": "36b038791e1e2baea892e9276588815fd14894b4", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kernel/fpu/core.c"], "versions": [{"version": "5.16", "status": "affected"}, {"version": "0", "lessThan": "5.16", "status": "unaffected", "versionType": "semver"}, {"version": "6.0.10", "lessThanOrEqual": "6.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1", "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": "5.16", "versionEndExcluding": "6.0.10"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/c6e8a7a1780af3da65e78a615f7d0874da6aabb0"}, {"url": "https://git.kernel.org/stable/c/36b038791e1e2baea892e9276588815fd14894b4"}], "title": "x86/fpu: Drop fpregs lock before inheriting FPU permissions", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/fpu: Drop fpregs lock before inheriting FPU permissions\n\nMike Galbraith reported the following against an old fork of preempt-rt\nbut the same issue also applies to the current preempt-rt tree.\n\n BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46\n in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: systemd\n preempt_count: 1, expected: 0\n RCU nest depth: 0, expected: 0\n Preemption disabled at:\n fpu_clone\n CPU: 6 PID: 1 Comm: systemd Tainted: G E (unreleased)\n Call Trace:\n <TASK>\n dump_stack_lvl\n ? fpu_clone\n __might_resched\n rt_spin_lock\n fpu_clone\n ? copy_thread\n ? copy_process\n ? shmem_alloc_inode\n ? kmem_cache_alloc\n ? kernel_clone\n ? __do_sys_clone\n ? do_syscall_64\n ? __x64_sys_rt_sigprocmask\n ? syscall_exit_to_user_mode\n ? do_syscall_64\n ? syscall_exit_to_user_mode\n ? do_syscall_64\n ? syscall_exit_to_user_mode\n ? do_syscall_64\n ? exc_page_fault\n ? entry_SYSCALL_64_after_hwframe\n </TASK>\n\nMike says:\n\n The splat comes from fpu_inherit_perms() being called under fpregs_lock(),\n and us reaching the spin_lock_irq() therein due to fpu_state_size_dynamic()\n returning true despite static key __fpu_state_size_dynamic having never\n been enabled.\n\nMike's assessment looks correct. fpregs_lock on a PREEMPT_RT kernel disables\npreemption so calling spin_lock_irq() in fpu_inherit_perms() is unsafe. This\nproblem exists since commit\n\n 9e798e9aa14c (\"x86/fpu: Prepare fpu_clone() for dynamically enabled features\").\n\nEven though the original bug report should not have enabled the paths at\nall, the bug still exists.\n\nfpregs_lock is necessary when editing the FPU registers or a task's FP\nstate but it is not necessary for fpu_inherit_perms(). The only write\nof any FP state in fpu_inherit_perms() is for the new child which is\nnot running yet and cannot context switch or be borrowed by a kernel\nthread yet. Hence, fpregs_lock is not protecting anything in the new\nchild until clone() completes and can be dropped earlier. The siglock\nstill needs to be acquired by fpu_inherit_perms() as the read of the\nparent's permissions has to be serialised.\n\n [ bp: Cleanup splat. ]"}], "id": "CVE-2022-49783", "lastModified": "2025-05-02T13:53:20.943", "metrics": {}, "published": "2025-05-01T15:16:01.510", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/36b038791e1e2baea892e9276588815fd14894b4"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c6e8a7a1780af3da65e78a615f7d0874da6aabb0"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: x86/fpu: Drop fpregs lock before inheriting FPU permissions", "id": "2363405", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2363405"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.1", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "details": ["In the Linux kernel, the following vulnerability has been resolved:\nx86/fpu: Drop fpregs lock before inheriting FPU permissions\nMike Galbraith reported the following against an old fork of preempt-rt\nbut the same issue also applies to the current preempt-rt tree.\nBUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46\nin_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: systemd\npreempt_count: 1, expected: 0\nRCU nest depth: 0, expected: 0\nPreemption disabled at:\nfpu_clone\nCPU: 6 PID: 1 Comm: systemd Tainted: G E (unreleased)\nCall Trace:\n<TASK>\ndump_stack_lvl\n? fpu_clone\n__might_resched\nrt_spin_lock\nfpu_clone\n? copy_thread\n? copy_process\n? shmem_alloc_inode\n? kmem_cache_alloc\n? kernel_clone\n? __do_sys_clone\n? do_syscall_64\n? __x64_sys_rt_sigprocmask\n? syscall_exit_to_user_mode\n? do_syscall_64\n? syscall_exit_to_user_mode\n? do_syscall_64\n? syscall_exit_to_user_mode\n? do_syscall_64\n? exc_page_fault\n? entry_SYSCALL_64_after_hwframe\n</TASK>\nMike says:\nThe splat comes from fpu_inherit_perms() being called under fpregs_lock(),\nand us reaching the spin_lock_irq() therein due to fpu_state_size_dynamic()\nreturning true despite static key __fpu_state_size_dynamic having never\nbeen enabled.\nMike's assessment looks correct. fpregs_lock on a PREEMPT_RT kernel disables\npreemption so calling spin_lock_irq() in fpu_inherit_perms() is unsafe. This\nproblem exists since commit\n9e798e9aa14c (\"x86/fpu: Prepare fpu_clone() for dynamically enabled features\").\nEven though the original bug report should not have enabled the paths at\nall, the bug still exists.\nfpregs_lock is necessary when editing the FPU registers or a task's FP\nstate but it is not necessary for fpu_inherit_perms(). The only write\nof any FP state in fpu_inherit_perms() is for the new child which is\nnot running yet and cannot context switch or be borrowed by a kernel\nthread yet. Hence, fpregs_lock is not protecting anything in the new\nchild until clone() completes and can be dropped earlier. The siglock\nstill needs to be acquired by fpu_inherit_perms() as the read of the\nparent's permissions has to be serialised.\n[ bp: Cleanup splat. ]"], "name": "CVE-2022-49783", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Out of support scope", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-05-01T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2022-49783\nhttps://nvd.nist.gov/vuln/detail/CVE-2022-49783\nhttps://lore.kernel.org/linux-cve-announce/2025050120-CVE-2022-49783-a870@gregkh/T"], "statement": "A bug in fpu_clone() could cause a sleeping function to be called in atomic context on PREEMPT_RT-enabled kernels, due to holding fpregs_lock() while calling fpu_inherit_perms(), which may invoke spin_lock_irq(). This results in a warning or kernel crash under certain conditions, particularly during process cloning with dynamic FPU state enabled.", "threat_severity": "Moderate"}