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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2020-11-12 18:27:31 +0100 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-11-13 02:36:52 +0100 |
| commit | 50b8a742850fce7293bed45753152c425f7e931b (patch) | |
| tree | 2e1a2a5174f4db385f491e143be0f6800a3c65c7 /init/main.c | |
| parent | kprobes: Tell lockdep about kprobe nesting (diff) | |
| download | linux-50b8a742850fce7293bed45753152c425f7e931b.tar.xz linux-50b8a742850fce7293bed45753152c425f7e931b.zip | |
bootconfig: Extend the magic check range to the preceding 3 bytes
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.
Link: https://lkml.kernel.org/r/160520205132.303174.4876760192433315429.stgit@devnote2
Cc: stable@vger.kernel.org
Fixes: 85c46b78da58 ("bootconfig: Add bootconfig magic word for indicating bootconfig explicitly")
Reported-by: Chen Yu <yu.chen.surf@gmail.com>
Tested-by: Chen Yu <yu.chen.surf@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'init/main.c')
| -rw-r--r-- | init/main.c | 14 |
1 files 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]; |