mok: fix LogError() invocation - #577
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This has been triggering a Synchronous Abort on my chromebook (rk3399-gru-kevin) when trying to run Debian's signed shim with U-Boot, thanks for fixing it. From what I can tell, U-Boot now has QueryVariableInfo() available, but can misreport maximum variable size when its variable store buffer is about to run out, due to an underflow in size calculation |
Debian's arm64 UEFI Secure Boot shim makes the EFI variable store run
out of space while mirroring its MOK database to variables. This can be
observed in QEMU like so:
$ tools/buildman/buildman -o build/qemu_arm64 --boards=qemu_arm64 -w
$ cd build/qemu_arm64
$ curl -L -o debian.iso \
https://cdimage.debian.org/debian-cd/current/arm64/iso-cd/debian-12.0.0-arm64-netinst.iso
$ qemu-system-aarch64 \
-nographic -bios u-boot.bin \
-machine virt -cpu cortex-a53 -m 1G -smp 2 \
-drive if=virtio,file=debian.iso,index=0,format=raw,readonly=on,media=cdrom
[...]
=> # interrupt autoboot
=> env set -e -bs -nv -rt -guid 605dab50-e046-4300-abb6-3dd810dd8b23 SHIM_VERBOSE 1
=> boot
[...]
mok.c:296:mirror_one_esl() SetVariable("MokListXRT43", ... varsz=0x4C) = Out of Resources
mok.c:452:mirror_mok_db() esd:0x7DB92D20 adj:0x30
Failed to set MokListXRT: Out of Resources
mok.c:767:mirror_one_mok_variable() mirror_mok_db("MokListXRT", datasz=17328) returned Out of Resources
mok.c:812:mirror_one_mok_variable() returning Out of Resources
Could not create MokListXRT: Out of Resources
[...]
Welcome to GRUB!
This would normally be fine as shim would continue to run grubaa64.efi,
but shim's error handling code for this case has a bug [1] that causes a
synchronous abort on at least chromebook_kevin (but apparently not on
QEMU arm64).
Double the default variable store size so the variables fit. There is a
note about this value matching PcdFlashNvStorageVariableSize when
EFI_MM_COMM_TEE is enabled, so keep the old default in that case.
[1] rhboot/shim#577
Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
jsetje
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I suppose we could also check that we weren't called with a null name, but that's arguably a separate issue.
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On some ARM platform, jlinton noticed that when we fail to set a variable (because it isn't supported at all, presumably), our error message has an extra argument that doesn't match the format string. This patch removes the extra argument. Resolves: CVE-2023-40546 Signed-off-by: Peter Jones <pjones@redhat.com>
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steve-mcintyre
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Looks good to me
What's changed * Various CVE fixes: CVE-2023-40546 mok: fix LogError() invocation CVE-2023-40547 - avoid incorrectly trusting HTTP headers CVE-2023-40548 Fix integer overflow on SBAT section size on 32-bit system CVE-2023-40549 Authenticode: verify that the signature header is in bounds. CVE-2023-40550 pe: Fix an out-of-bound read in verify_buffer_sbat() CVE-2023-40551: pe-relocate: Fix bounds check for MZ binaries * Add make infrastructure to set the NX_COMPAT flag by @vathpela in #530 * Make sbat_var.S parse right with buggy gcc/binutils by @vathpela in #535 * Drop invalid calls to CRYPTO_set_mem_functions by @nicholasbishop in #537 * pe: Align section size up to page size for mem attrs by @nicholasbishop in #539 * test-sbat: Fix exit code by @vathpela in #540 * pe: Add IS_PAGE_ALIGNED macro by @nicholasbishop in #541 * CryptoPkg/BaseCryptLib: Fix buffer overflow issue in realloc wrapper by @nicholasbishop in #546 * Don't loop forever in load_certs() with buggy firmware by @rmetrich in #547 * Block Debian grub binaries with SBAT < 4 by @steve-mcintyre in #550 * Shim unable to locate grubx64 in PXE boot mode when grubx64 is stored in a different file path by @Alberto-Perez-Guevara in #551 * Further improve load_certs() for non-compliant drivers/firmwares by @pbatard in #560 * pe: only process RelocDir->Size of reloc section by @mikebeaton in #562 * Rename 'msecs' to 'usecs' to avoid potential confusion by @aronowski in #563 * Optionally allow to keep shim protocol installed by @bluca in #565 * SBAT-related documents formatting and spelling by @aronowski in #566 * Add SbatLevel_Variable.txt to document the various revocations by @jsetje in #569 * Add a security contact email address in README.md by @vathpela in #572 * Use -Wno-unused-but-set-variable for Cryptlib and OpenSSL by @vathpela in #576 * mok: fix LogError() invocation by @vathpela in #577 * Minor housekeeping by @vathpela in #578 * Test ImageAddress() by @vathpela in #579 * FreePages() is used to return memory allocated by AllocatePages() by @dennis-tseng99 in #580 * Size should minus 1 when calculating 'RelocBaseEnd' by @jsetje in #581 * Verify signature before verifying sbat levels by @jsetje in #583 * Add libFuzzer support for csv.c and sbat.c by @vathpela in #584 * mok: Avoid underflow in maximum variable size calculation by @alpernebbi in #587 * Housekeeping by @vathpela in #605 Signed-off-by: Peter Jones <pjones@redhat.com>
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Is this issue actually a security vulnerability, or just a bug? Why was a CVE assigned? |
What's changed * Various CVE fixes: CVE-2023-40546 mok: fix LogError() invocation CVE-2023-40547 - avoid incorrectly trusting HTTP headers CVE-2023-40548 Fix integer overflow on SBAT section size on 32-bit system CVE-2023-40549 Authenticode: verify that the signature header is in bounds. CVE-2023-40550 pe: Fix an out-of-bound read in verify_buffer_sbat() CVE-2023-40551: pe-relocate: Fix bounds check for MZ binaries * Add make infrastructure to set the NX_COMPAT flag by @vathpela in rhboot#530 * Make sbat_var.S parse right with buggy gcc/binutils by @vathpela in rhboot#535 * Drop invalid calls to CRYPTO_set_mem_functions by @nicholasbishop in rhboot#537 * pe: Align section size up to page size for mem attrs by @nicholasbishop in rhboot#539 * test-sbat: Fix exit code by @vathpela in rhboot#540 * pe: Add IS_PAGE_ALIGNED macro by @nicholasbishop in rhboot#541 * CryptoPkg/BaseCryptLib: Fix buffer overflow issue in realloc wrapper by @nicholasbishop in rhboot#546 * Don't loop forever in load_certs() with buggy firmware by @rmetrich in rhboot#547 * Block Debian grub binaries with SBAT < 4 by @steve-mcintyre in rhboot#550 * Shim unable to locate grubx64 in PXE boot mode when grubx64 is stored in a different file path by @Alberto-Perez-Guevara in rhboot#551 * Further improve load_certs() for non-compliant drivers/firmwares by @pbatard in rhboot#560 * pe: only process RelocDir->Size of reloc section by @mikebeaton in rhboot#562 * Rename 'msecs' to 'usecs' to avoid potential confusion by @aronowski in rhboot#563 * Optionally allow to keep shim protocol installed by @bluca in rhboot#565 * SBAT-related documents formatting and spelling by @aronowski in rhboot#566 * Add SbatLevel_Variable.txt to document the various revocations by @jsetje in rhboot#569 * Add a security contact email address in README.md by @vathpela in rhboot#572 * Use -Wno-unused-but-set-variable for Cryptlib and OpenSSL by @vathpela in rhboot#576 * mok: fix LogError() invocation by @vathpela in rhboot#577 * Minor housekeeping by @vathpela in rhboot#578 * Test ImageAddress() by @vathpela in rhboot#579 * FreePages() is used to return memory allocated by AllocatePages() by @dennis-tseng99 in rhboot#580 * Size should minus 1 when calculating 'RelocBaseEnd' by @jsetje in rhboot#581 * Verify signature before verifying sbat levels by @jsetje in rhboot#583 * Add libFuzzer support for csv.c and sbat.c by @vathpela in rhboot#584 * mok: Avoid underflow in maximum variable size calculation by @alpernebbi in rhboot#587 * Housekeeping by @vathpela in rhboot#605 Signed-off-by: Peter Jones <pjones@redhat.com>
Debian's arm64 UEFI Secure Boot shim makes the EFI variable store run
out of space while mirroring its MOK database to variables. This can be
observed in QEMU like so:
$ tools/buildman/buildman -o build/qemu_arm64 --boards=qemu_arm64 -w
$ cd build/qemu_arm64
$ curl -L -o debian.iso \
https://cdimage.debian.org/debian-cd/current/arm64/iso-cd/debian-12.0.0-arm64-netinst.iso
$ qemu-system-aarch64 \
-nographic -bios u-boot.bin \
-machine virt -cpu cortex-a53 -m 1G -smp 2 \
-drive if=virtio,file=debian.iso,index=0,format=raw,readonly=on,media=cdrom
[...]
=> # interrupt autoboot
=> env set -e -bs -nv -rt -guid 605dab50-e046-4300-abb6-3dd810dd8b23 SHIM_VERBOSE 1
=> boot
[...]
mok.c:296:mirror_one_esl() SetVariable("MokListXRT43", ... varsz=0x4C) = Out of Resources
mok.c:452:mirror_mok_db() esd:0x7DB92D20 adj:0x30
Failed to set MokListXRT: Out of Resources
mok.c:767:mirror_one_mok_variable() mirror_mok_db("MokListXRT", datasz=17328) returned Out of Resources
mok.c:812:mirror_one_mok_variable() returning Out of Resources
Could not create MokListXRT: Out of Resources
[...]
Welcome to GRUB!
This would normally be fine as shim would continue to run grubaa64.efi,
but shim's error handling code for this case has a bug [1] that causes a
synchronous abort on at least chromebook_kevin (but apparently not on
QEMU arm64).
Double the default variable store size so the variables fit. There is a
note about this value matching PcdFlashNvStorageVariableSize when
EFI_MM_COMM_TEE is enabled, so keep the old default in that case.
[1] rhboot/shim#577
Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
On some ARM platform, jlinton noticed that when we fail to set a variable (because it isn't supported at all, presumably), our error message has an extra argument that doesn't match the format string.
This patch removes the extra argument.