From 7de1bc13e2aa05cdac651f032c58bb7f9744d490 Mon Sep 17 00:00:00 2001 From: Konstantin Belousov Date: Mon, 7 Sep 2020 21:37:16 +0000 Subject: [PATCH] imgact_elf.c: unify check for phdr fitting into the first page. Similar to the userspace rtld check. Reviewed by: dim, emaste (previous versions) Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D26339 --- sys/kern/imgact_elf.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c index 09a102ae0f9..776d7a9f08b 100644 --- a/sys/kern/imgact_elf.c +++ b/sys/kern/imgact_elf.c @@ -448,6 +448,13 @@ __elfN(get_brandinfo)(struct image_params *imgp, const char *interp, return (NULL); } +static bool +__elfN(phdr_in_zero_page)(const Elf_Ehdr *hdr) +{ + return (hdr->e_phoff <= PAGE_SIZE && + (u_int)hdr->e_phentsize * hdr->e_phnum <= PAGE_SIZE - hdr->e_phoff); +} + static int __elfN(check_header)(const Elf_Ehdr *hdr) { @@ -811,8 +818,7 @@ __elfN(load_file)(struct proc *p, const char *file, u_long *addr, } /* Only support headers that fit within first page for now */ - if ((hdr->e_phoff > PAGE_SIZE) || - (u_int)hdr->e_phentsize * hdr->e_phnum > PAGE_SIZE - hdr->e_phoff) { + if (!__elfN(phdr_in_zero_page)(hdr)) { error = ENOEXEC; goto fail; } @@ -1088,9 +1094,7 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp) * detected an ELF file. */ - if ((hdr->e_phoff > PAGE_SIZE) || - (u_int)hdr->e_phentsize * hdr->e_phnum > PAGE_SIZE - hdr->e_phoff) { - /* Only support headers in first page for now */ + if (!__elfN(phdr_in_zero_page)(hdr)) { uprintf("Program headers not in the first page\n"); return (ENOEXEC); }