[PATCH] KEYS: encrypted: Add check for strsep

[Verma, Vishal L]

On Wed, 2023-11-08 at 07:36 +0000, Chen Ni wrote:
> Add check for strsep() in order to transfer the error.
> 
> Fixes: cd3bc044af48 ("KEYS: encrypted: Instantiate key with user-
> provided decrypted data")
> Signed-off-by: Chen Ni <nichen at iscas.ac.cn>
> ---
>  security/keys/encrypted-keys/encrypted.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/security/keys/encrypted-keys/encrypted.c
> b/security/keys/encrypted-keys/encrypted.c
> index 8af2136069d2..76f55dd13cb8 100644
> --- a/security/keys/encrypted-keys/encrypted.c
> +++ b/security/keys/encrypted-keys/encrypted.c
> @@ -237,6 +237,10 @@ static int datablob_parse(char *datablob, const
> char **format,
>  			break;
>  		}
>  		*decrypted_data = strsep(&datablob, " \t");
> +		if (!*decrypted_data) {
> +			pr_info("encrypted_key: decrypted_data is
> missing\n");
> +			break;
> +		}

Hello,

This patch seems to break keyring usage in CXL and NVDIMM, with the
"decrypted_data is missing" error path being hit. Reverting this commit
fixes the tests. I'm not sure if there are valid scenarios where this is
expected to be empty?

Here's an strace snippet of where the error occurs:

   keyctl(KEYCTL_SEARCH, KEY_SPEC_USER_KEYRING, "user", "nvdimm-master", 0) = 76300785
   openat(AT_FDCWD, "/sys/devices/platform/cxl_acpi.0/root0/nvdimm-bridge0/ndbus0/nmem0/state", O_RDONLY|O_CLOEXEC) = 3
   read(3, "idle\n", 1024)                 = 5
   close(3)                                = 0
   keyctl(KEYCTL_SEARCH, KEY_SPEC_USER_KEYRING, "encrypted", "nvdimm:0", 0) = -1 ENOKEY (Required key not available)
   uname({sysname="Linux", nodename="fedora", ...}) = 0
   newfstatat(AT_FDCWD, "/etc/ndctl/keys/nvdimm_0_fedora.blob", 0x7fff23fbc210, 0) = -1 ENOENT (No such file or directory)
   add_key("encrypted", "nvdimm:0", "new enc32 user:nvdimm-master 32", 31, KEY_SPEC_USER_KEYRING) = -1 EINVAL (Invalid argument)