CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2021-47281 – ALSA: seq: Fix race of snd_seq_timer_open()
https://notcve.org/view.php?id=CVE-2021-47281
In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Fix race of snd_seq_timer_open() The timer instance per queue is exclusive, and snd_seq_timer_open() should have managed the concurrent accesses. It looks as if it's checking the already existing timer instance at the beginning, but it's not right, because there is no protection, hence any later concurrent call of snd_seq_timer_open() may override the timer instance easily. This may result in UAF, as the leftover timer instance can keep running while the queue itself gets closed, as spotted by syzkaller recently. For avoiding the race, add a proper check at the assignment of tmr->timeri again, and return -EBUSY if it's been already registered. En el kernel de Linux se ha resuelto la siguiente vulnerabilidad: ALSA: seq: Fix race of snd_seq_timer_open(). La instancia del temporizador por cola es exclusiva, y snd_seq_timer_open() debería haber gestionado los accesos concurrentes. • https://git.kernel.org/stable/c/bd7d88b0874f82f7b29d1a53e574cedaf23166ba https://git.kernel.org/stable/c/536a7646c00a0f14fee49e5e313109e5da2f6031 https://git.kernel.org/stable/c/83e197a8414c0ba545e7e3916ce05f836f349273 •
CVSS: -EPSS: 0%CPEs: 6EXPL: 0CVE-2021-47280 – drm: Fix use-after-free read in drm_getunique()
https://notcve.org/view.php?id=CVE-2021-47280
In the Linux kernel, the following vulnerability has been resolved: drm: Fix use-after-free read in drm_getunique() There is a time-of-check-to-time-of-use error in drm_getunique() due to retrieving file_priv->master prior to locking the device's master mutex. An example can be seen in the crash report of the use-after-free error found by Syzbot: https://syzkaller.appspot.com/bug?id=148d2f1dfac64af52ffd27b661981a540724f803 In the report, the master pointer was used after being freed. This is because another process had acquired the device's master mutex in drm_setmaster_ioctl(), then overwrote fpriv->master in drm_new_set_master(). The old value of fpriv->master was subsequently freed before the mutex was unlocked. To fix this, we lock the device's master mutex before retrieving the pointer from from fpriv->master. This patch passes the Syzbot reproducer test. • https://git.kernel.org/stable/c/17dab9326ff263c62dab1dbac4492e2938a049e4 https://git.kernel.org/stable/c/7d233ba700ceb593905ea82b42dadb4ec8ef85e9 https://git.kernel.org/stable/c/b246b4c70c1250e7814f409b243000f9c0bf79a3 https://git.kernel.org/stable/c/491d52e0078860b33b6c14f0a7ac74ca1b603bd6 https://git.kernel.org/stable/c/f773f8cccac13c7e7bbd9182e7996c727742488e https://git.kernel.org/stable/c/b436acd1cf7fac0ba987abd22955d98025c80c2b •
CVSS: -EPSS: 0%CPEs: 2EXPL: 0CVE-2021-47279 – usb: misc: brcmstb-usb-pinmap: check return value after calling platform_get_resource()
https://notcve.org/view.php?id=CVE-2021-47279
In the Linux kernel, the following vulnerability has been resolved: usb: misc: brcmstb-usb-pinmap: check return value after calling platform_get_resource() It will cause null-ptr-deref if platform_get_resource() returns NULL, we need check the return value. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: usb: misc: brcmstb-usb-pinmap: verifique el valor de retorno después de llamar a platform_get_resource() Causará un null-ptr-deref si platform_get_resource() devuelve NULL, necesitamos verificar el retorno valor. • https://git.kernel.org/stable/c/517c4c44b32372d2fdf4421822e21083c45e89f9 https://git.kernel.org/stable/c/2147684be1ebdaf845783139b9bc4eba3fecd9e4 https://git.kernel.org/stable/c/fbf649cd6d64d40c03c5397ecd6b1ae922ba7afc •
CVSS: -EPSS: 0%CPEs: 2EXPL: 0CVE-2021-47278 – bus: mhi: pci_generic: Fix possible use-after-free in mhi_pci_remove()
https://notcve.org/view.php?id=CVE-2021-47278
In the Linux kernel, the following vulnerability has been resolved: bus: mhi: pci_generic: Fix possible use-after-free in mhi_pci_remove() This driver's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: bus: mhi: pci_generic: corrige posible use after free en mhi_pci_remove(). La ruta de eliminación de este controlador llama a del_timer(). • https://git.kernel.org/stable/c/8562d4fe34a3ef52da077f77985994bb9ad1f83e https://git.kernel.org/stable/c/c597d5c59c7a6417dba06590f59b922e01188e8d https://git.kernel.org/stable/c/0b67808ade8893a1b3608ddd74fac7854786c919 •
CVSS: -EPSS: 0%CPEs: 8EXPL: 0CVE-2021-47277 – kvm: avoid speculation-based attacks from out-of-range memslot accesses
https://notcve.org/view.php?id=CVE-2021-47277
In the Linux kernel, the following vulnerability has been resolved: kvm: avoid speculation-based attacks from out-of-range memslot accesses KVM's mechanism for accessing guest memory translates a guest physical address (gpa) to a host virtual address using the right-shifted gpa (also known as gfn) and a struct kvm_memory_slot. The translation is performed in __gfn_to_hva_memslot using the following formula: hva = slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE It is expected that gfn falls within the boundaries of the guest's physical memory. However, a guest can access invalid physical addresses in such a way that the gfn is invalid. __gfn_to_hva_memslot is called from kvm_vcpu_gfn_to_hva_prot, which first retrieves a memslot through __gfn_to_memslot. While __gfn_to_memslot does check that the gfn falls within the boundaries of the guest's physical memory or not, a CPU can speculate the result of the check and continue execution speculatively using an illegal gfn. The speculation can result in calculating an out-of-bounds hva. • https://git.kernel.org/stable/c/3098b86390a6b9ea52657689f08410baf130ceff https://git.kernel.org/stable/c/740621309b25bbf619b8a0ba5fd50a8e58989441 https://git.kernel.org/stable/c/361ce3b917aff93123e9e966d8608655c967f438 https://git.kernel.org/stable/c/22b87fb17a28d37331bb9c1110737627b17f6781 https://git.kernel.org/stable/c/bff1fbf0cf0712686f1df59a83fba6e31d2746a0 https://git.kernel.org/stable/c/7af299b97734c7e7f465b42a2139ce4d77246975 https://git.kernel.org/stable/c/ed0e2a893092c7fcb4ff7ba74e5efce53a6f5940 https://git.kernel.org/stable/c/da27a83fd6cc7780fea190e1f5c19e870 •