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From: Yiyuan Guo <yguoaz@gmail.com>
To: code@tyhicks.com
Cc: viro@zeniv.linux.org.uk, brauner@kernel.org,
	ecryptfs@vger.kernel.org, linux-kernel@vger.kernel.org,
	yguoaz@gmail.com
Subject: [PATCH] ecryptfs: keystore: Fix a buffer overrun in write_tag_66_packet()
Date: Fri, 30 Jun 2023 17:11:55 +0800	[thread overview]
Message-ID: <20230630091155.373667-1-yguoaz@gmail.com> (raw)

The encrypted key of a TAG 66 Packet includes 1 byte cipher code and 2
byte checksum, but the allocation size `data_len` ignores the extra 3
bytes. Fix the allocation size to avoid buffer overrun.

Signed-off-by: Yiyuan Guo <yguoaz@gmail.com>
---
 fs/ecryptfs/keystore.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index 2452d6fd7062..5cab0b800a03 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -302,7 +302,7 @@ write_tag_66_packet(char *signature, u8 cipher_code,
 	 *         | File Encryption Key Size | 1 or 2 bytes |
 	 *         | File Encryption Key      | arbitrary    |
 	 */
-	data_len = (5 + ECRYPTFS_SIG_SIZE_HEX + crypt_stat->key_size);
+	data_len = (5 + ECRYPTFS_SIG_SIZE_HEX + crypt_stat->key_size + 3);
 	*packet = kmalloc(data_len, GFP_KERNEL);
 	message = *packet;
 	if (!message) {
-- 
2.25.1


                 reply	other threads:[~2023-06-30  9:12 UTC|newest]

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