* Patches queued for 2.6.32.8:

- FDPIC: Respect PT_GNU_STACK exec protection markings when creating
    NOMMU stack
  - Split 'flush_old_exec' into two functions (CVE-2010-0307)

svn path=/dists/trunk/linux-2.6/; revision=15102
This commit is contained in:
dann frazier 2010-02-02 23:38:40 +00:00
parent ec0059d2e1
commit 42ee301828
4 changed files with 356 additions and 0 deletions

4
debian/changelog vendored
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@ -11,6 +11,10 @@ linux-2.6 (2.6.32-7) UNRELEASED; urgency=low
[ dann frazier ]
* Disable FUNCTION_TRACER due to performance/build issues.
(Closes: #568025)
* Patches queued for 2.6.32.8:
- FDPIC: Respect PT_GNU_STACK exec protection markings when creating
NOMMU stack
- Split 'flush_old_exec' into two functions (CVE-2010-0307)
-- maximilian attems <maks@debian.org> Mon, 01 Feb 2010 17:16:31 +0100

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@ -0,0 +1,105 @@
From 04e4f2b18c8de1389d1e00fef0f42a8099910daf Mon Sep 17 00:00:00 2001
From: Mike Frysinger <vapier@gentoo.org>
Date: Wed, 6 Jan 2010 17:23:17 +0000
Subject: FDPIC: Respect PT_GNU_STACK exec protection markings when creating NOMMU stack
From: Mike Frysinger <vapier@gentoo.org>
commit 04e4f2b18c8de1389d1e00fef0f42a8099910daf upstream.
The current code will load the stack size and protection markings, but
then only use the markings in the MMU code path. The NOMMU code path
always passes PROT_EXEC to the mmap() call. While this doesn't matter
to most people whilst the code is running, it will cause a pointless
icache flush when starting every FDPIC application. Typically this
icache flush will be of a region on the order of 128KB in size, or may
be the entire icache, depending on the facilities available on the CPU.
In the case where the arch default behaviour seems to be desired
(EXSTACK_DEFAULT), we probe VM_STACK_FLAGS for VM_EXEC to determine
whether we should be setting PROT_EXEC or not.
For arches that support an MPU (Memory Protection Unit - an MMU without
the virtual mapping capability), setting PROT_EXEC or not will make an
important difference.
It should be noted that this change also affects the executability of
the brk region, since ELF-FDPIC has that share with the stack. However,
this is probably irrelevant as NOMMU programs aren't likely to use the
brk region, preferring instead allocation via mmap().
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
arch/blackfin/include/asm/page.h | 5 +++++
arch/frv/include/asm/page.h | 2 --
fs/binfmt_elf_fdpic.c | 13 +++++++++++--
3 files changed, 16 insertions(+), 4 deletions(-)
--- a/arch/blackfin/include/asm/page.h
+++ b/arch/blackfin/include/asm/page.h
@@ -10,4 +10,9 @@
#include <asm-generic/page.h>
#define MAP_NR(addr) (((unsigned long)(addr)-PAGE_OFFSET) >> PAGE_SHIFT)
+#define VM_DATA_DEFAULT_FLAGS \
+ (VM_READ | VM_WRITE | \
+ ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0 ) | \
+ VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+
#endif
--- a/arch/frv/include/asm/page.h
+++ b/arch/frv/include/asm/page.h
@@ -63,12 +63,10 @@ extern unsigned long max_pfn;
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
-#ifdef CONFIG_MMU
#define VM_DATA_DEFAULT_FLAGS \
(VM_READ | VM_WRITE | \
((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0 ) | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-#endif
#endif /* __ASSEMBLY__ */
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -171,6 +171,9 @@ static int load_elf_fdpic_binary(struct
#ifdef ELF_FDPIC_PLAT_INIT
unsigned long dynaddr;
#endif
+#ifndef CONFIG_MMU
+ unsigned long stack_prot;
+#endif
struct file *interpreter = NULL; /* to shut gcc up */
char *interpreter_name = NULL;
int executable_stack;
@@ -316,6 +319,8 @@ static int load_elf_fdpic_binary(struct
* defunct, deceased, etc. after this point we have to exit via
* error_kill */
set_personality(PER_LINUX_FDPIC);
+ if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
+ current->personality |= READ_IMPLIES_EXEC;
set_binfmt(&elf_fdpic_format);
current->mm->start_code = 0;
@@ -377,9 +382,13 @@ static int load_elf_fdpic_binary(struct
if (stack_size < PAGE_SIZE * 2)
stack_size = PAGE_SIZE * 2;
+ stack_prot = PROT_READ | PROT_WRITE;
+ if (executable_stack == EXSTACK_ENABLE_X ||
+ (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
+ stack_prot |= PROT_EXEC;
+
down_write(&current->mm->mmap_sem);
- current->mm->start_brk = do_mmap(NULL, 0, stack_size,
- PROT_READ | PROT_WRITE | PROT_EXEC,
+ current->mm->start_brk = do_mmap(NULL, 0, stack_size, stack_prot,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN,
0);

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@ -0,0 +1,245 @@
From 221af7f87b97431e3ee21ce4b0e77d5411cf1549 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Thu, 28 Jan 2010 22:14:42 -0800
Subject: Split 'flush_old_exec' into two functions
From: Linus Torvalds <torvalds@linux-foundation.org>
commit 221af7f87b97431e3ee21ce4b0e77d5411cf1549 upstream.
'flush_old_exec()' is the point of no return when doing an execve(), and
it is pretty badly misnamed. It doesn't just flush the old executable
environment, it also starts up the new one.
Which is very inconvenient for things like setting up the new
personality, because we want the new personality to affect the starting
of the new environment, but at the same time we do _not_ want the new
personality to take effect if flushing the old one fails.
As a result, the x86-64 '32-bit' personality is actually done using this
insane "I'm going to change the ABI, but I haven't done it yet" bit
(TIF_ABI_PENDING), with SET_PERSONALITY() not actually setting the
personality, but just the "pending" bit, so that "flush_thread()" can do
the actual personality magic.
This patch in no way changes any of that insanity, but it does split the
'flush_old_exec()' function up into a preparatory part that can fail
(still called flush_old_exec()), and a new part that will actually set
up the new exec environment (setup_new_exec()). All callers are changed
to trivially comply with the new world order.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
arch/sh/kernel/process_64.c | 2 +-
arch/x86/ia32/ia32_aout.c | 10 ++++++----
fs/binfmt_aout.c | 1 +
fs/binfmt_elf.c | 27 ++-------------------------
fs/binfmt_elf_fdpic.c | 3 +++
fs/binfmt_flat.c | 1 +
fs/binfmt_som.c | 1 +
fs/exec.c | 26 ++++++++++++++++----------
include/linux/binfmts.h | 1 +
include/linux/sched.h | 2 +-
10 files changed, 33 insertions(+), 41 deletions(-)
--- a/arch/sh/kernel/process_64.c
+++ b/arch/sh/kernel/process_64.c
@@ -367,7 +367,7 @@ void exit_thread(void)
void flush_thread(void)
{
- /* Called by fs/exec.c (flush_old_exec) to remove traces of a
+ /* Called by fs/exec.c (setup_new_exec) to remove traces of a
* previously running executable. */
#ifdef CONFIG_SH_FPU
if (last_task_used_math == current) {
--- a/arch/x86/ia32/ia32_aout.c
+++ b/arch/x86/ia32/ia32_aout.c
@@ -308,15 +308,17 @@ static int load_aout_binary(struct linux
if (retval)
return retval;
- regs->cs = __USER32_CS;
- regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
- regs->r13 = regs->r14 = regs->r15 = 0;
-
/* OK, This is the point of no return */
set_personality(PER_LINUX);
set_thread_flag(TIF_IA32);
clear_thread_flag(TIF_ABI_PENDING);
+ setup_new_exec(bprm);
+
+ regs->cs = __USER32_CS;
+ regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
+ regs->r13 = regs->r14 = regs->r15 = 0;
+
current->mm->end_code = ex.a_text +
(current->mm->start_code = N_TXTADDR(ex));
current->mm->end_data = ex.a_data +
--- a/fs/binfmt_aout.c
+++ b/fs/binfmt_aout.c
@@ -263,6 +263,7 @@ static int load_aout_binary(struct linux
#else
set_personality(PER_LINUX);
#endif
+ setup_new_exec(bprm);
current->mm->end_code = ex.a_text +
(current->mm->start_code = N_TXTADDR(ex));
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -662,27 +662,6 @@ static int load_elf_binary(struct linux_
if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
goto out_free_interp;
- /*
- * The early SET_PERSONALITY here is so that the lookup
- * for the interpreter happens in the namespace of the
- * to-be-execed image. SET_PERSONALITY can select an
- * alternate root.
- *
- * However, SET_PERSONALITY is NOT allowed to switch
- * this task into the new images's memory mapping
- * policy - that is, TASK_SIZE must still evaluate to
- * that which is appropriate to the execing application.
- * This is because exit_mmap() needs to have TASK_SIZE
- * evaluate to the size of the old image.
- *
- * So if (say) a 64-bit application is execing a 32-bit
- * application it is the architecture's responsibility
- * to defer changing the value of TASK_SIZE until the
- * switch really is going to happen - do this in
- * flush_thread(). - akpm
- */
- SET_PERSONALITY(loc->elf_ex);
-
interpreter = open_exec(elf_interpreter);
retval = PTR_ERR(interpreter);
if (IS_ERR(interpreter))
@@ -730,9 +709,6 @@ static int load_elf_binary(struct linux_
/* Verify the interpreter has a valid arch */
if (!elf_check_arch(&loc->interp_elf_ex))
goto out_free_dentry;
- } else {
- /* Executables without an interpreter also need a personality */
- SET_PERSONALITY(loc->elf_ex);
}
/* Flush all traces of the currently running executable */
@@ -752,7 +728,8 @@ static int load_elf_binary(struct linux_
if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
current->flags |= PF_RANDOMIZE;
- arch_pick_mmap_layout(current->mm);
+
+ setup_new_exec(bprm);
/* Do this so that we can load the interpreter, if need be. We will
change some of these later */
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -321,6 +321,9 @@ static int load_elf_fdpic_binary(struct
set_personality(PER_LINUX_FDPIC);
if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
current->personality |= READ_IMPLIES_EXEC;
+
+ setup_new_exec(bprm);
+
set_binfmt(&elf_fdpic_format);
current->mm->start_code = 0;
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -519,6 +519,7 @@ static int load_flat_file(struct linux_b
/* OK, This is the point of no return */
set_personality(PER_LINUX_32BIT);
+ setup_new_exec(bprm);
}
/*
--- a/fs/binfmt_som.c
+++ b/fs/binfmt_som.c
@@ -227,6 +227,7 @@ load_som_binary(struct linux_binprm * bp
/* OK, This is the point of no return */
current->flags &= ~PF_FORKNOEXEC;
current->personality = PER_HPUX;
+ setup_new_exec(bprm);
/* Set the task size for HP-UX processes such that
* the gateway page is outside the address space.
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -931,9 +931,7 @@ void set_task_comm(struct task_struct *t
int flush_old_exec(struct linux_binprm * bprm)
{
- char * name;
- int i, ch, retval;
- char tcomm[sizeof(current->comm)];
+ int retval;
/*
* Make sure we have a private signal table and that
@@ -953,6 +951,20 @@ int flush_old_exec(struct linux_binprm *
goto out;
bprm->mm = NULL; /* We're using it now */
+ return 0;
+
+out:
+ return retval;
+}
+EXPORT_SYMBOL(flush_old_exec);
+
+void setup_new_exec(struct linux_binprm * bprm)
+{
+ int i, ch;
+ char * name;
+ char tcomm[sizeof(current->comm)];
+
+ arch_pick_mmap_layout(current->mm);
/* This is the point of no return */
current->sas_ss_sp = current->sas_ss_size = 0;
@@ -1009,14 +1021,8 @@ int flush_old_exec(struct linux_binprm *
flush_signal_handlers(current, 0);
flush_old_files(current->files);
-
- return 0;
-
-out:
- return retval;
}
-
-EXPORT_SYMBOL(flush_old_exec);
+EXPORT_SYMBOL(setup_new_exec);
/*
* Prepare credentials and lock ->cred_guard_mutex.
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -101,6 +101,7 @@ extern int prepare_binprm(struct linux_b
extern int __must_check remove_arg_zero(struct linux_binprm *);
extern int search_binary_handler(struct linux_binprm *,struct pt_regs *);
extern int flush_old_exec(struct linux_binprm * bprm);
+extern void setup_new_exec(struct linux_binprm * bprm);
extern int suid_dumpable;
#define SUID_DUMP_DISABLE 0 /* No setuid dumping */
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1354,7 +1354,7 @@ struct task_struct {
char comm[TASK_COMM_LEN]; /* executable name excluding path
- access with [gs]et_task_comm (which lock
it with task_lock())
- - initialized normally by flush_old_exec */
+ - initialized normally by setup_new_exec */
/* file system info */
int link_count, total_link_count;
#ifdef CONFIG_SYSVIPC

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@ -1 +1,3 @@
+ bugfix/all/clocksource-events-Fix-fallout-of-generic-code-changes.patch
+ bugfix/all/fdpic-respect-pt_gnu_stack-exec-protection-markings-when-creating-nommu-stack.patch
+ bugfix/all/split-flush_old_exec-into-two-functions.patch