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authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-24 20:18:07 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-24 20:18:07 +0300
commita801695f68f40e75e47ed292bc9aaab815814b53 (patch)
tree97a21d0add3d31518b2dc79e151a01b7a0737a23 /init
parente61b2ad3e1914b70c657a8fd7524078ae37a7da4 (diff)
parent40c8ee67cfc49d00a13ccbf542e307b6b5421ad3 (diff)
downloadlinux-a801695f68f40e75e47ed292bc9aaab815814b53.tar.xz
Merge branch 'work.init' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro: "Followups to nodev root stuff from this merge window" * 'work.init' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: init: don't panic if mount_nodev_root failed init/do_mounts.c: Harden split_fs_names() against buffer overflow
Diffstat (limited to 'init')
-rw-r--r--init/do_mounts.c30
1 files changed, 16 insertions, 14 deletions
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 2ed30ff6c906..762b534978d9 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -338,20 +338,19 @@ __setup("rootflags=", root_data_setup);
__setup("rootfstype=", fs_names_setup);
__setup("rootdelay=", root_delay_setup);
-static int __init split_fs_names(char *page, char *names)
+/* This can return zero length strings. Caller should check */
+static int __init split_fs_names(char *page, size_t size, char *names)
{
- int count = 0;
+ int count = 1;
char *p = page;
- strcpy(p, root_fs_names);
+ strlcpy(p, root_fs_names, size);
while (*p++) {
- if (p[-1] == ',')
+ if (p[-1] == ',') {
p[-1] = '\0';
+ count++;
+ }
}
- *p = '\0';
-
- for (p = page; *p; p += strlen(p)+1)
- count++;
return count;
}
@@ -404,12 +403,16 @@ void __init mount_block_root(char *name, int flags)
scnprintf(b, BDEVNAME_SIZE, "unknown-block(%u,%u)",
MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
if (root_fs_names)
- num_fs = split_fs_names(fs_names, root_fs_names);
+ num_fs = split_fs_names(fs_names, PAGE_SIZE, root_fs_names);
else
num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
retry:
for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1) {
- int err = do_mount_root(name, p, flags, root_mount_data);
+ int err;
+
+ if (!*p)
+ continue;
+ err = do_mount_root(name, p, flags, root_mount_data);
switch (err) {
case 0:
goto out;
@@ -543,19 +546,18 @@ static int __init mount_nodev_root(void)
fs_names = (void *)__get_free_page(GFP_KERNEL);
if (!fs_names)
return -EINVAL;
- num_fs = split_fs_names(fs_names, root_fs_names);
+ num_fs = split_fs_names(fs_names, PAGE_SIZE, root_fs_names);
for (i = 0, fstype = fs_names; i < num_fs;
i++, fstype += strlen(fstype) + 1) {
+ if (!*fstype)
+ continue;
if (!fs_is_nodev(fstype))
continue;
err = do_mount_root(root_device_name, fstype, root_mountflags,
root_mount_data);
if (!err)
break;
- if (err != -EACCES && err != -EINVAL)
- panic("VFS: Unable to mount root \"%s\" (%s), err=%d\n",
- root_device_name, fstype, err);
}
free_page((unsigned long)fs_names);