exile_flags_to_landlock(): Only add flags for a path that a reasonable

This commit is contained in:
Albert S. 2022-01-08 12:19:31 +01:00
parent 4824c6eaa9
commit ff70142e04

43
exile.h
View File

@ -1415,22 +1415,38 @@ static int exile_enable_syscall_policy(struct exile_policy *policy)
} }
#if HAVE_LANDLOCK == 1 #if HAVE_LANDLOCK == 1
static unsigned int exile_flags_to_landlock(unsigned int flags) static unsigned int exile_flags_to_landlock(unsigned int flags, int statmode)
{ {
unsigned int result = 0; unsigned int result = 0;
if(flags & EXILE_FS_ALLOW_ALL_READ) if(flags & EXILE_FS_ALLOW_ALL_READ)
{ {
result |= LANDLOCK_ACCESS_FS_READ_FILE; result |= LANDLOCK_ACCESS_FS_READ_FILE;
if(S_ISDIR(statmode))
{
result |= LANDLOCK_ACCESS_FS_READ_DIR; result |= LANDLOCK_ACCESS_FS_READ_DIR;
} }
}
if(flags & EXILE_FS_ALLOW_ALL_WRITE) if(flags & EXILE_FS_ALLOW_ALL_WRITE)
{ {
result |= LANDLOCK_ACCESS_FS_MAKE_REG;
result |= LANDLOCK_ACCESS_FS_WRITE_FILE; result |= LANDLOCK_ACCESS_FS_WRITE_FILE;
result |= LANDLOCK_ACCESS_FS_REMOVE_DIR; if(S_ISDIR(statmode))
{
result |= LANDLOCK_ACCESS_FS_REMOVE_FILE; result |= LANDLOCK_ACCESS_FS_REMOVE_FILE;
result |= LANDLOCK_ACCESS_FS_MAKE_REG;
result |= LANDLOCK_ACCESS_FS_REMOVE_DIR;
result |= LANDLOCK_ACCESS_FS_MAKE_SYM; result |= LANDLOCK_ACCESS_FS_MAKE_SYM;
} }
}
if(flags & EXILE_FS_ALLOW_EXEC)
{
result |= LANDLOCK_ACCESS_FS_EXECUTE;
}
if(flags & EXILE_FS_ALLOW_WRITE_FILE)
{
result |= LANDLOCK_ACCESS_FS_WRITE_FILE;
}
if(S_ISDIR(statmode))
{
if(flags & EXILE_FS_ALLOW_DEV) if(flags & EXILE_FS_ALLOW_DEV)
{ {
result |= LANDLOCK_ACCESS_FS_MAKE_BLOCK; result |= LANDLOCK_ACCESS_FS_MAKE_BLOCK;
@ -1477,18 +1493,11 @@ static unsigned int exile_flags_to_landlock(unsigned int flags)
{ {
result |= LANDLOCK_ACCESS_FS_REMOVE_FILE; result |= LANDLOCK_ACCESS_FS_REMOVE_FILE;
} }
if(flags & EXILE_FS_ALLOW_EXEC)
{
result |= LANDLOCK_ACCESS_FS_EXECUTE;
}
if(flags & EXILE_FS_ALLOW_WRITE_FILE)
{
result |= LANDLOCK_ACCESS_FS_WRITE_FILE;
}
if(flags & EXILE_FS_ALLOW_READ_DIR) if(flags & EXILE_FS_ALLOW_READ_DIR)
{ {
result |= LANDLOCK_ACCESS_FS_READ_DIR; result |= LANDLOCK_ACCESS_FS_READ_DIR;
} }
}
return result; return result;
} }
@ -1518,8 +1527,16 @@ static int landlock_prepare_ruleset(struct exile_path_policy *policies)
close(ruleset_fd); close(ruleset_fd);
return path_beneath.parent_fd; return path_beneath.parent_fd;
} }
path_beneath.allowed_access = exile_flags_to_landlock(policy->policy); struct stat sb;
int ret = landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH, &path_beneath, 0); int ret = fstat(path_beneath.parent_fd, &sb);
if(ret)
{
EXILE_LOG_ERROR("landlock_prepare_ruleset(): fstat failed %s\n", strerror(errno));
close(ruleset_fd);
return ret;
}
path_beneath.allowed_access = exile_flags_to_landlock(policy->policy, sb.st_mode);
ret = landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH, &path_beneath, 0);
if(ret) if(ret)
{ {
EXILE_LOG_ERROR("Failed to update ruleset while processsing policy path %s\n", policy->path); EXILE_LOG_ERROR("Failed to update ruleset while processsing policy path %s\n", policy->path);