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authorKees Cook <keescook@chromium.org>2023-09-29 05:24:31 +0200
committerKees Cook <keescook@chromium.org>2023-09-29 18:54:27 +0200
commit8b04d32678e3c46b8a738178e0e55918eaa3be17 (patch)
treeac36398007ce897037fdc4b1cdeacfa8226a1e96 /fs/binfmt_elf.c
parentbinfmt_elf: elf_bss no longer used by load_elf_binary() (diff)
downloadlinux-8b04d32678e3c46b8a738178e0e55918eaa3be17.tar.xz
linux-8b04d32678e3c46b8a738178e0e55918eaa3be17.zip
binfmt_elf: Use elf_load() for interpreter
Handle arbitrary memsz>filesz in interpreter ELF segments, instead of only supporting it in the last segment (which is expected to be the BSS). Cc: Eric Biederman <ebiederm@xmission.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Reported-by: Pedro Falcato <pedro.falcato@gmail.com> Closes: https://lore.kernel.org/lkml/20221106021657.1145519-1-pedro.falcato@gmail.com/ Tested-by: Pedro Falcato <pedro.falcato@gmail.com> Signed-off-by: Sebastian Ott <sebott@redhat.com> Link: https://lore.kernel.org/r/20230929032435.2391507-3-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'fs/binfmt_elf.c')
-rw-r--r--fs/binfmt_elf.c46
1 files changed, 1 insertions, 45 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 0214d5a949fc..db47cb802f89 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -622,8 +622,6 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
struct elf_phdr *eppnt;
unsigned long load_addr = 0;
int load_addr_set = 0;
- unsigned long last_bss = 0, elf_bss = 0;
- int bss_prot = 0;
unsigned long error = ~0UL;
unsigned long total_size;
int i;
@@ -660,7 +658,7 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
else if (no_base && interp_elf_ex->e_type == ET_DYN)
load_addr = -vaddr;
- map_addr = elf_map(interpreter, load_addr + vaddr,
+ map_addr = elf_load(interpreter, load_addr + vaddr,
eppnt, elf_prot, elf_type, total_size);
total_size = 0;
error = map_addr;
@@ -686,51 +684,9 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
error = -ENOMEM;
goto out;
}
-
- /*
- * Find the end of the file mapping for this phdr, and
- * keep track of the largest address we see for this.
- */
- k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
- if (k > elf_bss)
- elf_bss = k;
-
- /*
- * Do the same thing for the memory mapping - between
- * elf_bss and last_bss is the bss section.
- */
- k = load_addr + eppnt->p_vaddr + eppnt->p_memsz;
- if (k > last_bss) {
- last_bss = k;
- bss_prot = elf_prot;
- }
}
}
- /*
- * Now fill out the bss section: first pad the last page from
- * the file up to the page boundary, and zero it from elf_bss
- * up to the end of the page.
- */
- if (padzero(elf_bss)) {
- error = -EFAULT;
- goto out;
- }
- /*
- * Next, align both the file and mem bss up to the page size,
- * since this is where elf_bss was just zeroed up to, and where
- * last_bss will end after the vm_brk_flags() below.
- */
- elf_bss = ELF_PAGEALIGN(elf_bss);
- last_bss = ELF_PAGEALIGN(last_bss);
- /* Finally, if there is still more bss to allocate, do it. */
- if (last_bss > elf_bss) {
- error = vm_brk_flags(elf_bss, last_bss - elf_bss,
- bss_prot & PROT_EXEC ? VM_EXEC : 0);
- if (error)
- goto out;
- }
-
error = load_addr;
out:
return error;