[2.6.25-rc2-mm1][2.6.25-rc3] Remove argv_len from struct linux_binprm

From: Tetsuo Handa
Date: Sun Feb 24 2008 - 19:55:31 EST


I noticed that 2.6.24.2 calculates bprm->argv_len at do_execve().
But it doesn't update bprm->argv_len after
"remove_arg_zero() + copy_strings_kernel()" at load_script() etc.

audit_bprm() is called from search_binary_handler()
and search_binary_handler() is called from load_script() etc.
Thus, I think the condition check

if (bprm->argv_len > (audit_argv_kb << 10))
return -E2BIG;

in audit_bprm() might return wrong result
when strlen(removed_arg) != strlen(spliced_args).
Why not update bprm->argv_len at load_script() etc. ?


By the way, 2.6.25-rc3 seems to not doing the condition check.
Is the field bprm->argv_len no longer needed?

Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
---
fs/exec.c | 3 ---
include/linux/binfmts.h | 1 -
2 files changed, 4 deletions(-)

--- linux-2.6.25-rc3.orig/fs/exec.c
+++ linux-2.6.25-rc3/fs/exec.c
@@ -1274,7 +1274,6 @@ int do_execve(char * filename,
{
struct linux_binprm *bprm;
struct file *file;
- unsigned long env_p;
int retval;

retval = -ENOMEM;
@@ -1322,11 +1321,9 @@ int do_execve(char * filename,
if (retval < 0)
goto out;

- env_p = bprm->p;
retval = copy_strings(bprm->argc, argv, bprm);
if (retval < 0)
goto out;
- bprm->argv_len = env_p - bprm->p;

retval = search_binary_handler(bprm,regs);
if (retval >= 0) {
--- linux-2.6.25-rc3.orig/include/linux/binfmts.h
+++ linux-2.6.25-rc3/include/linux/binfmts.h
@@ -48,7 +48,6 @@ struct linux_binprm{
unsigned interp_flags;
unsigned interp_data;
unsigned long loader, exec;
- unsigned long argv_len;
};

#define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
--
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