From: Kees Cook keescook@chromium.org
commit d5ca24f639588811af57ceac513183fa2004bd3a upstream
While load_elf_library() is a libc5-ism, we can still replace most of its contents with elf_load() as well, further simplifying the code.
Some historical context: - libc4 was a.out and used uselib (a.out support has been removed) - libc5 was ELF and used uselib (there may still be users) - libc6 is ELF and has never used uselib
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 Suggested-by: Eric Biederman ebiederm@xmission.com Tested-by: Pedro Falcato pedro.falcato@gmail.com Signed-off-by: Sebastian Ott sebott@redhat.com Link: https://lore.kernel.org/r/20230929032435.2391507-4-keescook@chromium.org Signed-off-by: Kees Cook keescook@chromium.org Signed-off-by: Wenlin Kang wenlin.kang@windriver.com --- fs/binfmt_elf.c | 24 ++++-------------------- 1 file changed, 4 insertions(+), 20 deletions(-)
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 64c5e5cd0cd8..ba1ef7e3f9f3 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1308,7 +1308,6 @@ static int load_elf_library(struct file *file) { struct elf_phdr *elf_phdata; struct elf_phdr *eppnt; - unsigned long elf_bss, bss, len; int retval, error, i, j; struct elfhdr elf_ex;
@@ -1353,30 +1352,15 @@ static int load_elf_library(struct file *file) eppnt++;
/* Now use mmap to map the library into memory. */ - error = vm_mmap(file, - ELF_PAGESTART(eppnt->p_vaddr), - (eppnt->p_filesz + - ELF_PAGEOFFSET(eppnt->p_vaddr)), + error = elf_load(file, ELF_PAGESTART(eppnt->p_vaddr), + eppnt, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_FIXED_NOREPLACE | MAP_PRIVATE, - (eppnt->p_offset - - ELF_PAGEOFFSET(eppnt->p_vaddr))); - if (error != ELF_PAGESTART(eppnt->p_vaddr)) - goto out_free_ph; + 0);
- elf_bss = eppnt->p_vaddr + eppnt->p_filesz; - if (padzero(elf_bss)) { - error = -EFAULT; + if (error != ELF_PAGESTART(eppnt->p_vaddr)) goto out_free_ph; - }
- len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr); - bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr); - if (bss > len) { - error = vm_brk(len, bss - len); - if (error) - goto out_free_ph; - } error = 0;
out_free_ph: