From 79bc12a0a09c2eb1ccbb01c192045f994567bda2 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 21 May 2008 06:32:11 +0100 Subject: [PATCH] ecryptfs fixes memcpy() from userland pointer is a Bad Thing(tm) Signed-off-by: Al Viro Signed-off-by: Linus Torvalds --- fs/ecryptfs/miscdev.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/fs/ecryptfs/miscdev.c b/fs/ecryptfs/miscdev.c index 6560da1a58..50c994a249 100644 --- a/fs/ecryptfs/miscdev.c +++ b/fs/ecryptfs/miscdev.c @@ -243,7 +243,6 @@ ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count, struct ecryptfs_daemon *daemon; struct ecryptfs_msg_ctx *msg_ctx; size_t packet_length_size; - u32 counter_nbo; char packet_length[3]; size_t i; size_t total_length; @@ -328,20 +327,18 @@ check_list: "pending message\n", __func__, count, total_length); goto out_unlock_msg_ctx; } - i = 0; - buf[i++] = msg_ctx->type; - counter_nbo = cpu_to_be32(msg_ctx->counter); - memcpy(&buf[i], (char *)&counter_nbo, 4); - i += 4; + rc = -EFAULT; + if (put_user(msg_ctx->type, buf)) + goto out_unlock_msg_ctx; + if (put_user(cpu_to_be32(msg_ctx->counter), (__be32 __user *)(buf + 1))) + goto out_unlock_msg_ctx; + i = 5; if (msg_ctx->msg) { - memcpy(&buf[i], packet_length, packet_length_size); + if (copy_to_user(&buf[i], packet_length, packet_length_size)) + goto out_unlock_msg_ctx; i += packet_length_size; - rc = copy_to_user(&buf[i], msg_ctx->msg, msg_ctx->msg_size); - if (rc) { - printk(KERN_ERR "%s: copy_to_user returned error " - "[%d]\n", __func__, rc); + if (copy_to_user(&buf[i], msg_ctx->msg, msg_ctx->msg_size)) goto out_unlock_msg_ctx; - } i += msg_ctx->msg_size; } rc = i; @@ -452,7 +449,8 @@ static ssize_t ecryptfs_miscdev_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { - u32 counter_nbo, seq; + __be32 counter_nbo; + u32 seq; size_t packet_size, packet_size_length, i; ssize_t sz = 0; char *data; @@ -485,7 +483,7 @@ ecryptfs_miscdev_write(struct file *file, const char __user *buf, count); goto out_free; } - memcpy((char *)&counter_nbo, &data[i], 4); + memcpy(&counter_nbo, &data[i], 4); seq = be32_to_cpu(counter_nbo); i += 4; rc = ecryptfs_parse_packet_length(&data[i], &packet_size, -- 2.39.5