From 73dddffc3175581ba99f6ced9a2e508a0e880e59 Mon Sep 17 00:00:00 2001 From: Konstantin Belousov Date: Fri, 15 Oct 2021 20:59:37 +0300 Subject: [PATCH] crt_malloc: more accurate handling of mmap(2) failure Reset both pagepool_start and pagepool_end after a mmap(2) failure, to avoid using invalid pagepool either for allocation or munmap(2). PR: 259076 Noted by: Denis Koreshkov Reviewed by: arichardson Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D32514 --- libexec/rtld-elf/rtld_malloc.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/libexec/rtld-elf/rtld_malloc.c b/libexec/rtld-elf/rtld_malloc.c index 64218b5bb786..63fa6f5e2ee7 100644 --- a/libexec/rtld-elf/rtld_malloc.c +++ b/libexec/rtld-elf/rtld_malloc.c @@ -271,21 +271,21 @@ morepages(int n) } } - if (pagepool_start == MAP_FAILED) - pagepool_start = 0; offset = (uintptr_t)pagepool_start - rounddown2( (uintptr_t)pagepool_start, pagesz); - pagepool_start = mmap(0, n * pagesz, PROT_READ | PROT_WRITE, + addr = mmap(0, n * pagesz, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0); - if (pagepool_start == MAP_FAILED) { + if (addr == MAP_FAILED) { #ifdef IN_RTLD rtld_fdprintf(STDERR_FILENO, _BASENAME_RTLD ": morepages: " "cannot mmap anonymous memory: %s\n", rtld_strerror(errno)); #endif + pagepool_start = pagepool_end = NULL; return (0); } + pagepool_start = addr; pagepool_end = pagepool_start + n * pagesz; pagepool_start += offset;