6.18-stable review patch. If anyone has any objections, please let me know.
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From: Thorsten Blum thorsten.blum@linux.dev
[ Upstream commit df0845cf447ae1556c3440b8b155de0926cbaa56 ]
Use check_add_overflow() to guard against potential integer overflows when adding the binary blob lengths and the size of an asymmetric_key_id structure and return ERR_PTR(-EOVERFLOW) accordingly. This prevents a possible buffer overflow when copying data from potentially malicious X.509 certificate fields that can be arbitrarily large, such as ASN.1 INTEGER serial numbers, issuer names, etc.
Fixes: 7901c1a8effb ("KEYS: Implement binary asymmetric key ID handling") Signed-off-by: Thorsten Blum thorsten.blum@linux.dev Reviewed-by: Lukas Wunner lukas@wunner.de Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- crypto/asymmetric_keys/asymmetric_type.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index ba2d9d1ea235a..348966ea2175c 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -11,6 +11,7 @@ #include <crypto/public_key.h> #include <linux/seq_file.h> #include <linux/module.h> +#include <linux/overflow.h> #include <linux/slab.h> #include <linux/ctype.h> #include <keys/system_keyring.h> @@ -141,12 +142,17 @@ struct asymmetric_key_id *asymmetric_key_generate_id(const void *val_1, size_t len_2) { struct asymmetric_key_id *kid; - - kid = kmalloc(sizeof(struct asymmetric_key_id) + len_1 + len_2, - GFP_KERNEL); + size_t kid_sz; + size_t len; + + if (check_add_overflow(len_1, len_2, &len)) + return ERR_PTR(-EOVERFLOW); + if (check_add_overflow(sizeof(struct asymmetric_key_id), len, &kid_sz)) + return ERR_PTR(-EOVERFLOW); + kid = kmalloc(kid_sz, GFP_KERNEL); if (!kid) return ERR_PTR(-ENOMEM); - kid->len = len_1 + len_2; + kid->len = len; memcpy(kid->data, val_1, len_1); memcpy(kid->data + len_1, val_2, len_2); return kid;