From: Masami Hiramatsu <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Chen Yu <yu.c.chen@intel.com>, Chen Yu <yu.chen.surf@gmail.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH] bootconfig: Extend the magic check range to the preceding 3 bytes
Date: Fri, 13 Nov 2020 02:27:31 +0900 [thread overview]
Message-ID: <160520205132.303174.4876760192433315429.stgit@devnote2> (raw)
In-Reply-To: <20201113003633.8db2b4e4c5fecf8de0adfa65@kernel.org>
Since Grub may align the size of initrd to 4 if user pass
initrd from cpio, we have to check the preceding 3 bytes as well.
Fixes: 85c46b78da58 ("bootconfig: Add bootconfig magic word for indicating bootconfig explicitly")
Reported-by: Chen Yu <yu.chen.surf@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
init/main.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/init/main.c b/init/main.c
index 130376ec10ba..20baced721ad 100644
--- a/init/main.c
+++ b/init/main.c
@@ -269,14 +269,24 @@ static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
u32 size, csum;
char *data;
u32 *hdr;
+ int i;
if (!initrd_end)
return NULL;
data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
- if (memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
- return NULL;
+ /*
+ * Since Grub may align the size of initrd to 4, we must
+ * check the preceding 3 bytes as well.
+ */
+ for (i = 0; i < 4; i++) {
+ if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
+ goto found;
+ data--;
+ }
+ return NULL;
+found:
hdr = (u32 *)(data - 8);
size = hdr[0];
csum = hdr[1];
next prev parent reply other threads:[~2020-11-12 17:27 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 15:39 bootconfig length parse error in kernel Chen Yu
2020-11-11 9:37 ` Masami Hiramatsu
2020-11-12 4:34 ` Chen Yu
2020-11-12 5:50 ` Masami Hiramatsu
2020-11-12 6:49 ` Chen Yu
2020-11-12 15:36 ` Masami Hiramatsu
2020-11-12 17:27 ` Masami Hiramatsu [this message]
2020-11-13 1:27 ` [PATCH] bootconfig: Extend the magic check range to the preceding 3 bytes Chen Yu
2020-11-13 2:21 ` Masami Hiramatsu
2020-11-13 3:16 ` Steven Rostedt
2020-11-13 0:49 ` bootconfig length parse error in kernel Chen Yu
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