The patch titled
VFS: fix passing of AT_PHDR value in auxv to ELF interpreter
has been added to the -mm tree. Its filename is
vfs-fix-passing-of-at_phdr-value-in-auxv-to-elf-interpreter.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: VFS: fix passing of AT_PHDR value in auxv to ELF interpreter
From: Quentin Godfroy <godfroy@xxxxxxxxxxxxxx>
On a dynamic ELF executable, the current kernel loader gives to the
interpreter (in the AUXV vector) the AT_PHDR argument as :
offset_of_phdr_in_file + first address.
It can be wrong for an executable where the program headers are not located
in the first loaded segment.
This patch corrects the behaviour.
Signed-off-by: Quentin Godfroy <godfroy@xxxxxxxxxxxxxx>
Cc: "David A. Madore" <David.Madore@xxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Cc: Jakub Jelinek <jakub@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/binfmt_elf.c | 17 ++++++++++++++---
1 files changed, 14 insertions(+), 3 deletions(-)
diff -puN fs/binfmt_elf.c~vfs-fix-passing-of-at_phdr-value-in-auxv-to-elf-interpreter fs/binfmt_elf.c
--- a/fs/binfmt_elf.c~vfs-fix-passing-of-at_phdr-value-in-auxv-to-elf-interpreter
+++ a/fs/binfmt_elf.c
@@ -134,6 +134,7 @@ static int padzero(unsigned long elf_bss
static int
create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
int interp_aout, unsigned long load_addr,
+ unsigned long phdr_addr,
unsigned long interp_load_addr)
{
unsigned long p = bprm->p;
@@ -190,7 +191,7 @@ create_elf_tables(struct linux_binprm *b
NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
- NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
+ NEW_AUX_ENT(AT_PHDR, phdr_addr);
NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
NEW_AUX_ENT(AT_BASE, interp_load_addr);
@@ -529,7 +530,7 @@ static unsigned long randomize_stack_top
static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
{
struct file *interpreter = NULL; /* to shut gcc up */
- unsigned long load_addr = 0, load_bias = 0;
+ unsigned long load_addr = 0, load_bias = 0, phdr_addr = 0;
int load_addr_set = 0;
char * elf_interpreter = NULL;
unsigned int interpreter_type = INTERPRETER_NONE;
@@ -718,6 +719,16 @@ static int load_elf_binary(struct linux_
break;
}
+ elf_ppnt = elf_phdata;
+ for (i = 0; i< loc->elf_ex.e_phnum; i++, elf_ppnt++)
+ if (elf_ppnt->p_type == PT_PHDR) {
+ phdr_addr = elf_ppnt->p_vaddr;
+ break;
+ }
+ retval = -ENOEXEC;
+ if (!phdr_addr)
+ goto out_free_dentry;
+
/* Some simple consistency checks for the interpreter */
if (elf_interpreter) {
interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
@@ -987,7 +998,7 @@ static int load_elf_binary(struct linux_
current->flags &= ~PF_FORKNOEXEC;
create_elf_tables(bprm, &loc->elf_ex,
(interpreter_type == INTERPRETER_AOUT),
- load_addr, interp_load_addr);
+ load_addr, phdr_addr, interp_load_addr);
/* N.B. passed_fileno might not be initialized? */
if (interpreter_type == INTERPRETER_AOUT)
current->mm->arg_start += strlen(passed_fileno) + 1;
_
Patches currently in -mm which might be from godfroy@xxxxxxxxxxxxxx are
vfs-fix-passing-of-at_phdr-value-in-auxv-to-elf-interpreter.patch
-
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