[PATCH] KEYS: fix overflow in keyctl_pkey_params_get_2()
From: Jarkko Sakkinen <jarkko@kernel.org>
Date: 2026-05-31 02:49:30
Also in:
keyrings, lkml, stable
Subsystem:
keys/keyrings, security subsystem, the rest · Maintainers:
David Howells, Jarkko Sakkinen, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
The length for the internal output buffer is calculated incorrectly, which
can result overflow when a too small buffer is provided.
Fix the bug by allocating internal output with the size of the maximum
length of the cryptographic primitive instead of caller provided size.
Cc: stable@vger.kernel.org # v4.20+
Fixes: 00d60fd3b932 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]")
Reported-by: Alessandro Grupp <redacted>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
Alessandro, please correct if I put the last name correctly (and
sincere apologies if not).
security/keys/keyctl_pkey.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/security/keys/keyctl_pkey.c b/security/keys/keyctl_pkey.c
index 97bc27bbf079..ba150ee2d4a3 100644
--- a/security/keys/keyctl_pkey.c
+++ b/security/keys/keyctl_pkey.c@@ -138,28 +138,35 @@ static int keyctl_pkey_params_get_2(const struct keyctl_pkey_params __user *_par if (uparams.in_len > info.max_dec_size || uparams.out_len > info.max_enc_size) return -EINVAL; + + params->out_len = info.max_enc_size; break; case KEYCTL_PKEY_DECRYPT: if (uparams.in_len > info.max_enc_size || uparams.out_len > info.max_dec_size) return -EINVAL; + + params->out_len = info.max_dec_size; break; case KEYCTL_PKEY_SIGN: if (uparams.in_len > info.max_data_size || uparams.out_len > info.max_sig_size) return -EINVAL; + + params->out_len = info.max_sig_size; break; case KEYCTL_PKEY_VERIFY: if (uparams.in_len > info.max_data_size || uparams.in2_len > info.max_sig_size) return -EINVAL; + + params->out_len = info.max_sig_size; break; default: BUG(); } params->in_len = uparams.in_len; - params->out_len = uparams.out_len; /* Note: same as in2_len */ return 0; } --
2.47.3