From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: linux-efi@vger.kernel.org, linux-crypto@vger.kernel.org
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>,
Ard Biesheuvel <ardb@kernel.org>,
Lennart Poettering <lennart@poettering.net>
Subject: [PATCH RFC v1 5/6] efi: efivarfs: prohibit reading random seed variables
Date: Wed, 16 Nov 2022 17:16:41 +0100 [thread overview]
Message-ID: <20221116161642.1670235-6-Jason@zx2c4.com> (raw)
In-Reply-To: <20221116161642.1670235-1-Jason@zx2c4.com>
Variables in the random seed GUID must remain secret, so deny all reads
to them.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
fs/efivarfs/file.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
index d57ee15874f9..08996ba3a373 100644
--- a/fs/efivarfs/file.c
+++ b/fs/efivarfs/file.c
@@ -76,6 +76,9 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
while (!__ratelimit(&file->f_cred->user->ratelimit))
msleep(50);
+ if (guid_equal(&var->var.VendorGuid, &LINUX_EFI_RANDOM_SEED_TABLE_GUID))
+ return -EPERM;
+
err = efivar_entry_size(var, &datasize);
/*
--
2.38.1
next prev parent reply other threads:[~2022-11-16 16:17 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-16 16:16 [PATCH RFC v1 0/6] Use EFI variables for random seed Jason A. Donenfeld
2022-11-16 16:16 ` [PATCH RFC v1 1/6] random: add back async readiness notifier Jason A. Donenfeld
2022-11-19 12:37 ` [lkp] [+84 bytes kernel size regression] [i386-tinyconfig] [538cb30493] " kernel test robot
2022-11-16 16:16 ` [PATCH RFC v1 2/6] vsprintf: initialize siphash key using notifier Jason A. Donenfeld
2022-11-18 14:16 ` Petr Mladek
2022-11-18 14:20 ` Jason A. Donenfeld
2022-11-16 16:16 ` [PATCH RFC v1 3/6] efi: random: combine bootloader provided RNG seed with RNG protocol output Jason A. Donenfeld
2022-11-16 16:16 ` [PATCH RFC v1 4/6] efi: stub: use random seed from EFI variable Jason A. Donenfeld
2022-11-16 16:16 ` Jason A. Donenfeld [this message]
2022-11-16 17:04 ` [PATCH RFC v1 5/6] efi: efivarfs: prohibit reading random seed variables Ard Biesheuvel
2022-11-16 18:56 ` Jason A. Donenfeld
2022-11-16 19:42 ` James Bottomley
2022-11-16 20:08 ` Jason A. Donenfeld
2022-11-27 21:36 ` James Bottomley
2022-11-16 16:16 ` [PATCH RFC v1 6/6] efi: refresh non-volatile random seed when RNG is initialized Jason A. Donenfeld
2022-11-16 17:59 ` [PATCH RFC v1 0/6] Use EFI variables for random seed Lennart Poettering
2022-11-16 18:57 ` Jason A. Donenfeld
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