linker: Handle a truncated hints file properly

If vattr.va_size is 0, we will end up accessing invalid memory.  This is
mostly harmless (because malloc(0) still allocates some memory), but it
triggers a KASAN report.

PR:		282268
Reviewed by:	christos, imp
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D47240
This commit is contained in:
Mark Johnston 2024-10-23 16:54:56 +00:00
parent dab59af3bc
commit b5149b2653

View File

@ -2030,6 +2030,10 @@ linker_hints_lookup(const char *path, int pathlen, const char *modname,
printf("linker.hints file too large %ld\n", (long)vattr.va_size);
goto bad;
}
if (vattr.va_size < sizeof(ival)) {
printf("linker.hints file truncated\n");
goto bad;
}
hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);