dm-crypt: reject the lmk IV mode with AEAD ciphers
A "capi:" table line that pairs an AEAD cipher with the lmk IV mode,
for example "capi:gcm(aes)-lmk" with the integrity:28:aead option,
causes an oops when it is loaded. lmk sets tfms_count to 64, but
crypt_alloc_tfms_aead only allocates one transform, so crypt_setkey
reads past the end of the tfms_aead array and calls crypto_aead_setkey
on the values it finds there.
lmk exists for compatibility with Loop-AES, which uses CBC, so refuse
it with an AEAD cipher rather than allocate 64 AEAD transforms. The
check cannot go in crypt_iv_lmk_ctr with the other lmk checks, because
the IV constructor runs after crypt_set_key.
Note that this is not a security bug because the memory corruption can
only be triggered by root.
Analysis
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Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||
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| Linux | Linux | unaffected |
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| Linux | Linux | affected |
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Fri, 23 Oct 2026 12:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: dm-crypt: reject the lmk IV mode with AEAD ciphers A "capi:" table line that pairs an AEAD cipher with the lmk IV mode, for example "capi:gcm(aes)-lmk" with the integrity:28:aead option, causes an oops when it is loaded. lmk sets tfms_count to 64, but crypt_alloc_tfms_aead only allocates one transform, so crypt_setkey reads past the end of the tfms_aead array and calls crypto_aead_setkey on the values it finds there. lmk exists for compatibility with Loop-AES, which uses CBC, so refuse it with an AEAD cipher rather than allocate 64 AEAD transforms. The check cannot go in crypt_iv_lmk_ctr with the other lmk checks, because the IV constructor runs after crypt_set_key. Note that this is not a security bug because the memory corruption can only be triggered by root. | |
| Title | dm-crypt: reject the lmk IV mode with AEAD ciphers | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-23T12:21:54.317Z
Reserved: 2026-09-25T10:25:14.387Z
Link: CVE-2026-99037
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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No weakness.