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romfs: check the dirent before use it 

System will crash when the romfs is erased. Add checks before using them
to avoid it.
This commit is contained in:
Grissiom 2014-11-03 12:10:25 +08:00
parent 3531fa71aa
commit e882597f9c
1 changed files with 28 additions and 4 deletions
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32
components/dfs/filesystems/romfs/dfs_romfs.c
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@ -49,6 +49,14 @@ int dfs_romfs_ioctl(struct dfs_fd *file, int cmd, void *args)
return -DFS_STATUS_EIO; return -DFS_STATUS_EIO;
} }
rt_inline int check_dirent(struct romfs_dirent *dirent)
{
if (!(dirent->type == ROMFS_DIRENT_FILE || dirent->type == ROMFS_DIRENT_DIR) ||
(dirent->size == 0 || dirent->size == ~0))
return -1;
return 0;
}
struct romfs_dirent *dfs_romfs_lookup(struct romfs_dirent *root_dirent, const char *path, rt_size_t *size) struct romfs_dirent *dfs_romfs_lookup(struct romfs_dirent *root_dirent, const char *path, rt_size_t *size)
{ {
rt_size_t index, found; rt_size_t index, found;
@ -56,6 +64,10 @@ struct romfs_dirent *dfs_romfs_lookup(struct romfs_dirent *root_dirent, const ch
struct romfs_dirent *dirent; struct romfs_dirent *dirent;
rt_size_t dirent_size; rt_size_t dirent_size;
/* Check the root_dirent. */
if (check_dirent(root_dirent) != 0)
return RT_NULL;
if (path[0] == '/' && path[1] == '\0') if (path[0] == '/' && path[1] == '\0')
{ {
*size = root_dirent->size; *size = root_dirent->size;
@ -82,6 +94,8 @@ struct romfs_dirent *dfs_romfs_lookup(struct romfs_dirent *root_dirent, const ch
/* search in folder */ /* search in folder */
for (index = 0; index < dirent_size; index ++) for (index = 0; index < dirent_size; index ++)
{ {
if (check_dirent(&dirent[index]) != 0)
return RT_NULL;
if (rt_strncmp(dirent[index].name, subpath, (subpath_end - subpath)) == 0) if (rt_strncmp(dirent[index].name, subpath, (subpath_end - subpath)) == 0)
{ {
dirent_size = dirent[index].size; dirent_size = dirent[index].size;
@ -133,6 +147,11 @@ int dfs_romfs_read(struct dfs_fd *file, void *buf, rt_size_t count)
dirent = (struct romfs_dirent *)file->data; dirent = (struct romfs_dirent *)file->data;
RT_ASSERT(dirent != RT_NULL); RT_ASSERT(dirent != RT_NULL);
if (check_dirent(dirent) != 0)
{
return -DFS_STATUS_EIO;
}
if (count < file->size - file->pos) if (count < file->size - file->pos)
length = count; length = count;
else else
@ -172,6 +191,9 @@ int dfs_romfs_open(struct dfs_fd *file)
root_dirent = (struct romfs_dirent *)file->fs->data; root_dirent = (struct romfs_dirent *)file->fs->data;
if (check_dirent(dirent) != 0)
return -DFS_STATUS_EIO;
if (file->flags & (DFS_O_CREAT | DFS_O_WRONLY | DFS_O_APPEND | DFS_O_TRUNC | DFS_O_RDWR)) if (file->flags & (DFS_O_CREAT | DFS_O_WRONLY | DFS_O_APPEND | DFS_O_TRUNC | DFS_O_RDWR))
return -DFS_STATUS_EINVAL; return -DFS_STATUS_EINVAL;
@ -236,16 +258,18 @@ int dfs_romfs_getdents(struct dfs_fd *file, struct dirent *dirp, rt_uint32_t cou
struct romfs_dirent *dirent, *sub_dirent; struct romfs_dirent *dirent, *sub_dirent;
dirent = (struct romfs_dirent *)file->data; dirent = (struct romfs_dirent *)file->data;
if (check_dirent(dirent) != 0)
return -DFS_STATUS_EIO;
RT_ASSERT(dirent->type == ROMFS_DIRENT_DIR); RT_ASSERT(dirent->type == ROMFS_DIRENT_DIR);
/* enter directory */ /* enter directory */
dirent = (struct romfs_dirent *)dirent->data; dirent = (struct romfs_dirent *)dirent->data;
/* make integer count */ /* make integer count */
count = (count / sizeof(struct dirent)); count = (count / sizeof(struct dirent));
if (count == 0) if (count == 0)
return -DFS_STATUS_EINVAL; return -DFS_STATUS_EINVAL;
index = 0; index = 0;
for (index = 0; index < count && file->pos < file->size; index ++) for (index = 0; index < count && file->pos < file->size; index ++)
{ {
@ -265,13 +289,13 @@ int dfs_romfs_getdents(struct dfs_fd *file, struct dirent *dirp, rt_uint32_t cou
rt_strncpy(d->d_name, name, rt_strlen(name) + 1); rt_strncpy(d->d_name, name, rt_strlen(name) + 1);
/* move to next position */ /* move to next position */
++ file->pos; ++ file->pos;
} }
return index * sizeof(struct dirent); return index * sizeof(struct dirent);
} }
static const struct dfs_filesystem_operation _romfs = static const struct dfs_filesystem_operation _romfs =
{ {
"rom", "rom",
DFS_FS_FLAG_DEFAULT, DFS_FS_FLAG_DEFAULT,