Messages in this thread | | | Subject | Re: Re: Re: PING: [PATCH] crypto: public_key: fix overflow during implicit conversion | From | zhenwei pi <> | Date | Thu, 19 Aug 2021 18:52:23 +0800 |
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On 8/19/21 6:35 PM, Jarkko Sakkinen wrote: > On Thu, 2021-08-19 at 10:03 +0800, zhenwei pi wrote: >> On 8/18/21 8:33 PM, Jarkko Sakkinen wrote: >>> On Wed, 2021-08-18 at 16:33 +0800, zhenwei pi wrote: >>>> PING >>> >>> Please, do not top-post. >>> >>> You are lacking Herbert Xu: >>> >>> $ scripts/get_maintainer.pl crypto/asymmetric_keys/public_key.c >>> David Howells <dhowells@redhat.com> (maintainer:ASYMMETRIC KEYS) >>> Herbert Xu <herbert@gondor.apana.org.au> (maintainer:CRYPTO API) >>> "David S. Miller" <davem@davemloft.net> (maintainer:CRYPTO API) >>> keyrings@vger.kernel.org (open list:ASYMMETRIC KEYS) >>> linux-crypto@vger.kernel.org (open list:CRYPTO API) >>> linux-kernel@vger.kernel.org (open list) >>> >>>> On 8/10/21 2:39 PM, zhenwei pi wrote: >>>>> Hit kernel warning like this, it can be reproduced by verifying >>>>> 256 >>>>> bytes datafile by keyctl command. >>>>> >>>>> WARNING: CPU: 5 PID: 344556 at crypto/rsa-pkcs1pad.c:540 >>>>> pkcs1pad_verify+0x160/0x190 >>>>> ... >>>>> Call Trace: >>>>> public_key_verify_signature+0x282/0x380 >>>>> ? software_key_query+0x12d/0x180 >>>>> ? keyctl_pkey_params_get+0xd6/0x130 >>>>> asymmetric_key_verify_signature+0x66/0x80 >>>>> keyctl_pkey_verify+0xa5/0x100 >>>>> do_syscall_64+0x35/0xb0 >>>>> entry_SYSCALL_64_after_hwframe+0x44/0xae >>>>> >>>>> '.digest_size(u8) = params->in_len(u32)' leads overflow of an >>>>> u8 >>> >>> Where is this statement? >>> >> >> In function "static int asymmetric_key_verify_signature(struct >> kernel_pkey_params *params, const void *in, const void *in2)" >> >>>>> value, >>>>> so use u32 instead of u8 of digest. And reorder struct >>>>> public_key_signature, it could save 8 bytes on a 64 bit >>>>> machine. >>> ~~~~~ >>> 64-bit >>> >>> What do you mean by "could"? Does it, or does it >>> not? >>> >>> >>> >> After reordering struct public_key_signature, sizeof(struct >> public_key_signature) gets smaller than the original version. > > OK, then just state is as "it saves" instead of "it could save". > > Not a requirement but have you been able to trigger this for a > kernel that does not have this fix? > This kernel warning can be reproduced on debian11(Linux-5.10.0-8-amd64) by the following script:
RAWDATA=rawdata SIGDATA=sigdata
modprobe pkcs8_key_parser
rm -rf *.der *.pem *.pfx rm -rf $RAWDATA dd if=/dev/random of=$RAWDATA bs=256 count=1
openssl req -nodes -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -subj "/C=CN/ST=GD/L=SZ/O=vihoo/OU=dev/CN=xx.com/emailAddress=yy@xx.com"
KEY_ID=`openssl pkcs8 -in key.pem -topk8 -nocrypt -outform DER | keyctl padd asymmetric 123 @s`
keyctl pkey_sign $KEY_ID 0 $RAWDATA enc=pkcs1 hash=sha1 > $SIGDATA keyctl pkey_verify $KEY_ID 0 $RAWDATA $SIGDATA enc=pkcs1 hash=sha1
> /Jarkko >
-- zhenwei pi
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