binfmt_elf: elf_bss no longer used by load_elf_binary()

[ Upstream commit 8ed2ef21ff564cf4a25c098ace510ee6513c9836 ]

With the BSS handled generically via the new filesz/memsz mismatch
handling logic in elf_load(), elf_bss no longer needs to be tracked.
Drop the variable.

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
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/20230929032435.2391507-2-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Stable-dep-of: 11854fe263eb ("binfmt_elf: Move brk for static PIE even if ASLR disabled")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index d59bca23c4bd9bc13890a98febf8d6b341a6ae40..02258b28e370e07f0043590cbb8ee7b31e202e95 100644 (file)
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -854,7 +854,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
        unsigned long error;
        struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
        struct elf_phdr *elf_property_phdata = NULL;
-       unsigned long elf_bss, elf_brk;
+       unsigned long elf_brk;
        int retval, i;
        unsigned long elf_entry;
        unsigned long e_entry;
@@ -1046,7 +1046,6 @@ out_free_interp:
        if (retval < 0)
                goto out_free_dentry;
 
-       elf_bss = 0;
        elf_brk = 0;
 
        start_code = ~0UL;
@@ -1209,8 +1208,6 @@ out_free_interp:
 
                k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
 
-               if (k > elf_bss)
-                       elf_bss = k;
                if ((elf_ppnt->p_flags & PF_X) && end_code < k)
                        end_code = k;
                if (end_data < k)
@@ -1222,7 +1219,6 @@ out_free_interp:
 
        e_entry = elf_ex->e_entry + load_bias;
        phdr_addr += load_bias;
-       elf_bss += load_bias;
        elf_brk += load_bias;
        start_code += load_bias;
        end_code += load_bias;