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fs: Prevent overflows when assigning returned values from read_number()

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The direct assignment of the unsigned long long value returned by
read_number() can potentially lead to an overflow on a 32-bit systems.
The fix replaces the direct assignments with calls to grub_cast()
which detects the overflows and safely assigns the values if no
overflow is detected.

Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Lidong Chen 2025-01-21 19:02:38 +00:00 committed by Daniel Kiper
parent 84bc0a9a68
commit cde9f7f338
2 changed files with 30 additions and 11 deletions
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18
grub-core/fs/cpio_common.c
View File

@ -62,11 +62,21 @@ grub_cpio_find_file (struct grub_archelp_data *data, char **name,
#endif
)
return grub_error (GRUB_ERR_BAD_FS, "invalid cpio archive");
data->size = read_number (hd.filesize, ARRAY_SIZE (hd.filesize));
if (grub_cast (read_number (hd.filesize, ARRAY_SIZE (hd.filesize)), &data->size))
return grub_error (GRUB_ERR_BAD_FS, N_("data size overflow"));
if (mtime)
*mtime = read_number (hd.mtime, ARRAY_SIZE (hd.mtime));
modeval = read_number (hd.mode, ARRAY_SIZE (hd.mode));
namesize = read_number (hd.namesize, ARRAY_SIZE (hd.namesize));
{
if (grub_cast (read_number (hd.mtime, ARRAY_SIZE (hd.mtime)), mtime))
return grub_error (GRUB_ERR_BAD_FS, N_("mtime overflow"));
}
if (grub_cast (read_number (hd.mode, ARRAY_SIZE (hd.mode)), &modeval))
return grub_error (GRUB_ERR_BAD_FS, N_("mode overflow"));
if (grub_cast (read_number (hd.namesize, ARRAY_SIZE (hd.namesize)), &namesize))
return grub_error (GRUB_ERR_BAD_FS, N_("namesize overflow"));
/* Don't allow negative numbers. */
if (namesize >= 0x80000000)

23
grub-core/fs/tar.c
View File

@ -99,9 +99,10 @@ grub_cpio_find_file (struct grub_archelp_data *data, char **name,
if (hd.typeflag == 'L')
{
grub_err_t err;
grub_size_t namesize = read_number (hd.size, sizeof (hd.size));
grub_size_t namesize;
if (grub_add (namesize, 1, &sz))
if (grub_cast (read_number (hd.size, sizeof (hd.size)), &namesize) ||
grub_add (namesize, 1, &sz))
return grub_error (GRUB_ERR_BAD_FS, N_("name size overflow"));
*name = grub_malloc (sz);
@ -123,9 +124,10 @@ grub_cpio_find_file (struct grub_archelp_data *data, char **name,
if (hd.typeflag == 'K')
{
grub_err_t err;
grub_size_t linksize = read_number (hd.size, sizeof (hd.size));
grub_size_t linksize;
if (grub_add (linksize, 1, &sz))
if (grub_cast (read_number (hd.size, sizeof (hd.size)), &linksize) ||
grub_add (linksize, 1, &sz))
return grub_error (GRUB_ERR_BAD_FS, N_("link size overflow"));
if (data->linkname_alloc < sz)
@ -174,15 +176,22 @@ grub_cpio_find_file (struct grub_archelp_data *data, char **name,
(*name)[extra_size + sizeof (hd.name)] = 0;
}
data->size = read_number (hd.size, sizeof (hd.size));
if (grub_cast (read_number (hd.size, sizeof (hd.size)), &data->size))
return grub_error (GRUB_ERR_BAD_FS, N_("data size overflow"));
data->dofs = data->hofs + GRUB_DISK_SECTOR_SIZE;
data->next_hofs = data->dofs + ((data->size + GRUB_DISK_SECTOR_SIZE - 1) &
~(GRUB_DISK_SECTOR_SIZE - 1));
if (mtime)
*mtime = read_number (hd.mtime, sizeof (hd.mtime));
{
if (grub_cast (read_number (hd.mtime, sizeof (hd.mtime)), mtime))
return grub_error (GRUB_ERR_BAD_FS, N_("mtime overflow"));
}
if (mode)
{
*mode = read_number (hd.mode, sizeof (hd.mode));
if (grub_cast (read_number (hd.mode, sizeof (hd.mode)), mode))
return grub_error (GRUB_ERR_BAD_FS, N_("mode overflow"));
switch (hd.typeflag)
{
/* Hardlink. */