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CVE-2023-52463 — efivarfs: force RO when remounting if SetVariable is not supported

Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

efivarfs: force RO when remounting if SetVariable is not supported

If SetVariable at runtime is not supported by the firmware we never assign a callback for that function. At the same time mount the efivarfs as RO so no one can call that. However, we never check the permission flags when someone remounts the filesystem as RW. As a result this leads to a crash looking like this:

$ mount -o remount,rw /sys/firmware/efi/efivars $ efi-updatevar -f PK.auth PK

[ 303.279166] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 303.280482] Mem abort info: [ 303.280854] ESR = 0x0000000086000004 [ 303.281338] EC = 0x21: IABT (current EL), IL = 32 bits [ 303.282016] SET = 0, FnV = 0 [ 303.282414] EA = 0, S1PTW = 0 [ 303.282821] FSC = 0x04: level 0 translation fault [ 303.283771] user pgtable: 4k pages, 48-bit VAs, pgdp=000000004258c000 [ 303.284913] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 [ 303.286076] Internal error: Oops: 0000000086000004 [#1] PREEMPT SMP [ 303.286936] Modules linked in: qrtr tpm_tis tpm_tis_core crct10dif_ce arm_smccc_trng rng_core drm fuse ip_tables x_tables ipv6 [ 303.288586] CPU: 1 PID: 755 Comm: efi-updatevar Not tainted 6.3.0-rc1-00108-gc7d0c4695c68 #1 [ 303.289748] Hardware name: Unknown Unknown Product/Unknown Product, BIOS 2023.04-00627-g88336918701d 04/01/2023 [ 303.291150] pstate: 60400005 (nZCv daif +PAN…

USN-6688-1 — linux-oem-6.1 vulnerabilities

Affected: Ubuntu:22.04:LTS: linux-oem-6.1

Pratyush Yadav discovered that the Xen network backend implementation in the Linux kernel did not properly handle zero length data request, leading to a null pointer dereference vulnerability. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2023-46838)

It was discovered that the Habana's AI Processors driver in the Linux kernel did not properly initialize certain data structures before passing them to user space. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2023-50431)

Murray McAllister discovered that the VMware Virtual GPU DRM driver in the Linux kernel did not properly handle memory objects when storing surfaces, leading to a use-after-free vulnerability. A local attacker in a guest VM could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2023-5633)

It was discovered that the CIFS network file system implementation in the Linux kernel did not properly validate certain SMB messages, leading to an out-of-bounds read vulnerability. An attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information. (CVE-2023-6610)

It was discovered that the VirtIO subsystem in the Linux kernel did not properly initialize memory in some situations. A local attacker could use this to possibly expose sensitive information (kernel memory). (CVE-2024-0340)

Lonial Con discovered that the netfilter subsystem…