efivarfs: force RO when remounting if SetVariable is not sup… (CVE-2023-52463)

Summary

efivarfs: force RO when remounting if SetVariable is not supported

Original description

The description as published by the source.

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 -…

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

Affected packages

Linux Kernel

[{"type":"ECOSYSTEM","events":[{"introduced":"5.8.0"},{"fixed":"5.10.209"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.148"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.75"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.14"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.7.2"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

Debian DEBIAN-CVE-2023-52463 linux Fixed in: 5.10.209-1
Ubuntu UBUNTU-CVE-2023-52463 linux-hwe-edge

Summary

Original description

Affected packages

Fix status by distribution

References