Oops in 2.4.7-pre9.

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* Oops in 2.4.7-pre9.
@ 2001-07-20  6:16 Niels Kristian Bech Jensen
  2001-07-20  6:26 ` David S. Miller
  2001-07-20  6:52 ` Andrew Morton
  0 siblings, 2 replies; 5+ messages in thread
From: Niels Kristian Bech Jensen @ 2001-07-20  6:16 UTC (permalink / raw)
  To: Linux kernel developer's mailing list

I get this oops while booting 2.4.7-pre9:

Jul 20 08:01:52 hafnium kernel: Unable to handle kernel NULL pointer dereference at virtual address 0000007c
Jul 20 08:01:52 hafnium kernel: c01467e3
Jul 20 08:01:52 hafnium kernel: *pde = 00000000
Jul 20 08:01:52 hafnium kernel: Oops: 0000
Jul 20 08:01:52 hafnium kernel: CPU:    0
Jul 20 08:01:52 hafnium kernel: EIP:    0010:[proc_pid_make_inode+131/176]
Jul 20 08:01:52 hafnium kernel: EIP:    0010:[<c01467e3>]
Using defaults from ksymoops -t elf32-i386 -a i386
Jul 20 08:01:52 hafnium kernel: EFLAGS: 00010206
Jul 20 08:01:52 hafnium kernel: eax: 00000000   ebx: c11ba000   ecx: c48c89c0   edx: c104b578
Jul 20 08:01:52 hafnium kernel: esi: c11ed000   edi: 0000000b   ebp: c01e0ca0   esp: c493de68
Jul 20 08:01:52 hafnium kernel: ds: 0018   es: 0018   ss: 0018
Jul 20 08:01:52 hafnium kernel: Process pidof (pid: 177, stackpage=c493d000)
Jul 20 08:01:52 hafnium kernel: Stack: c11ba000 0000000b c01bf0aa c0146a3a c11ed000 c11ba000 0000000b c11ba000
Jul 20 08:01:52 hafnium kernel:        ffffffea fffffff4 c01406a8 c1157e08 000000f0 c4b6c9a0 fffffff4 c48c87e0
Jul 20 08:01:52 hafnium kernel:        c4b6c920 c01388cf c48c87e0 c4b6c9a0 c493df00 c4b6c920 c4b6c920 c4fee00c
Jul 20 08:01:52 hafnium kernel: Call Trace: [proc_base_lookup+138/544] [d_alloc+24/368] [real_lookup+79/192] [path_walk+1409/2000] [destroy_inode+48/64] [open_namei+124/1360] [filp_open+52/96]
Jul 20 08:01:52 hafnium kernel: Call Trace: [<c0146a3a>] [<c01406a8>] [<c01388cf>] [<c0138fd1>] [<c0141050>] [<c013972c>] [<c012e334>]
Jul 20 08:01:52 hafnium kernel:        [<c013861f>] [<c012e636>] [<c0106cf3>]
Jul 20 08:01:52 hafnium kernel: Code: f6 40 7c 01 74 12 8b 83 24 01 00 00 89 41 30 8b 83 34 01 00

>>EIP; c01467e3 <proc_pid_make_inode+83/b0>   <=====
Trace; c0146a3a <proc_base_lookup+8a/220>
Trace; c01406a8 <d_alloc+18/170>
Trace; c01388cf <real_lookup+4f/c0>
Trace; c0138fd1 <path_walk+581/7d0>
Trace; c0141050 <destroy_inode+30/40>
Trace; c013972c <open_namei+7c/550>
Trace; c012e334 <filp_open+34/60>
Trace; c013861f <getname+5f/a0>
Trace; c012e636 <sys_open+36/b0>
Trace; c0106cf3 <system_call+33/40>
Code;  c01467e3 <proc_pid_make_inode+83/b0>
00000000 <_EIP>:
Code;  c01467e3 <proc_pid_make_inode+83/b0>   <=====
   0:   f6 40 7c 01               testb  $0x1,0x7c(%eax)   <=====
Code;  c01467e7 <proc_pid_make_inode+87/b0>
   4:   74 12                     je     18 <_EIP+0x18> c01467fb <proc_pid_make_inode+9b/b0>
Code;  c01467e9 <proc_pid_make_inode+89/b0>
   6:   8b 83 24 01 00 00         mov    0x124(%ebx),%eax
Code;  c01467ef <proc_pid_make_inode+8f/b0>
   c:   89 41 30                  mov    %eax,0x30(%ecx)
Code;  c01467f2 <proc_pid_make_inode+92/b0>
   f:   8b 83 34 01 00 00         mov    0x134(%ebx),%eax



-- 
Niels Kristian Bech Jensen -- nkbj@image.dk -- http://www.image.dk/~nkbj/

----------->>  Stop software piracy --- use free software!  <<-----------


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: Oops in 2.4.7-pre9.
  2001-07-20  6:16 Oops in 2.4.7-pre9 Niels Kristian Bech Jensen
@ 2001-07-20  6:26 ` David S. Miller
  2001-07-20  7:27   ` Niels Kristian Bech Jensen
  2001-07-20  6:52 ` Andrew Morton
  1 sibling, 1 reply; 5+ messages in thread
From: David S. Miller @ 2001-07-20  6:26 UTC (permalink / raw)
  To: Niels Kristian Bech Jensen; +Cc: Linux kernel developer's mailing list


Niels Kristian Bech Jensen writes:
 > >>EIP; c01467e3 <proc_pid_make_inode+83/b0>   <=====

This should fix it:

--- fs/proc/base.c.~1~	Thu Jul 19 23:02:12 2001
+++ fs/proc/base.c	Thu Jul 19 23:25:28 2001
@@ -670,7 +670,8 @@
 	inode->u.proc_i.task = task;
 	inode->i_uid = 0;
 	inode->i_gid = 0;
-	if (ino == PROC_PID_INO || task->mm->dumpable) {
+	if (ino == PROC_PID_INO ||
+	    (task->mm && task->mm->dumpable)) {
 		inode->i_uid = task->euid;
 		inode->i_gid = task->egid;
 	}

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: Oops in 2.4.7-pre9.
  2001-07-20  6:26 ` David S. Miller
@ 2001-07-20  7:27   ` Niels Kristian Bech Jensen
  0 siblings, 0 replies; 5+ messages in thread
From: Niels Kristian Bech Jensen @ 2001-07-20  7:27 UTC (permalink / raw)
  To: David S. Miller; +Cc: Linux kernel developer's mailing list

On Thu, 19 Jul 2001, David S. Miller wrote:

>
> Niels Kristian Bech Jensen writes:
>  > >>EIP; c01467e3 <proc_pid_make_inode+83/b0>   <=====
>
> This should fix it:
>
It does, thanks.

-- 
Niels Kristian Bech Jensen -- nkbj@image.dk -- http://www.image.dk/~nkbj/

----------->>  Stop software piracy --- use free software!  <<-----------


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: Oops in 2.4.7-pre9.
  2001-07-20  6:16 Oops in 2.4.7-pre9 Niels Kristian Bech Jensen
  2001-07-20  6:26 ` David S. Miller
@ 2001-07-20  6:52 ` Andrew Morton
  2001-07-20  8:10   ` Linus Torvalds
  1 sibling, 1 reply; 5+ messages in thread
From: Andrew Morton @ 2001-07-20  6:52 UTC (permalink / raw)
  To: Niels Kristian Bech Jensen
  Cc: Linux kernel developer's mailing list, Linus Torvalds

Niels Kristian Bech Jensen wrote:
> 
> I get this oops while booting 2.4.7-pre9:

Kernel is trying to read /proc/pid entries for a kernel thread
which has called daemonize().  It has a null task_struct.mm.

I tested various other possible problems, such as making
/sbin/hotplug an elf executable and it looks OK, apart from
the /proc problem.

--- linux-2.4.7-pre9/fs/proc/base.c	Fri Jul 20 15:39:12 2001
+++ linux-akpm/fs/proc/base.c	Fri Jul 20 16:43:02 2001
@@ -670,7 +670,7 @@ static struct inode *proc_pid_make_inode
 	inode->u.proc_i.task = task;
 	inode->i_uid = 0;
 	inode->i_gid = 0;
-	if (ino == PROC_PID_INO || task->mm->dumpable) {
+	if (ino == PROC_PID_INO || (task->mm && task->mm->dumpable)) {
 		inode->i_uid = task->euid;
 		inode->i_gid = task->egid;
 	}

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: Oops in 2.4.7-pre9.
  2001-07-20  6:52 ` Andrew Morton
@ 2001-07-20  8:10   ` Linus Torvalds
  0 siblings, 0 replies; 5+ messages in thread
From: Linus Torvalds @ 2001-07-20  8:10 UTC (permalink / raw)
  To: Andrew Morton
  Cc: Niels Kristian Bech Jensen, Linux kernel developer's mailing list



On Fri, 20 Jul 2001, Andrew Morton wrote:
>
> I tested various other possible problems, such as making
> /sbin/hotplug an elf executable and it looks OK, apart from
> the /proc problem.

Actually, there's a double stupidity in the dumpable testing: it should
really test that the process has a VM, but it should also make sure to
lock that access properly.

This ends up being even more of an issue for ptrace, I think. Sorry for
the screw-up.  I think the real fix should be something along the lines of
this (actually, we should move the whole ptrace executable test into
ptrace_dumpable: right now x86 is the only one that gets the subtle and
unlikely race with a ptrace and a suid executable right with the memory
access ordering things).

		Linus

----
diff -u --recursive --new-file pre9/linux/arch/alpha/kernel/ptrace.c linux/arch/alpha/kernel/ptrace.c
--- pre9/linux/arch/alpha/kernel/ptrace.c	Fri Jul 20 01:02:50 2001
+++ linux/arch/alpha/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -267,7 +267,7 @@
 		ret = -EPERM;
 		if (child == current)
 			goto out;
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		     (current->uid != child->euid) ||
 		     (current->uid != child->suid) ||
 		     (current->uid != child->uid) ||
diff -u --recursive --new-file pre9/linux/arch/arm/kernel/ptrace.c linux/arch/arm/kernel/ptrace.c
--- pre9/linux/arch/arm/kernel/ptrace.c	Fri Jul 20 01:02:50 2001
+++ linux/arch/arm/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -596,7 +596,7 @@
 	if (request == PTRACE_ATTACH) {
 		if (child == current)
 			goto out_tsk;
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		    (current->uid != child->euid) ||
 		    (current->uid != child->suid) ||
 		    (current->uid != child->uid) ||
diff -u --recursive --new-file pre9/linux/arch/cris/kernel/ptrace.c linux/arch/cris/kernel/ptrace.c
--- pre9/linux/arch/cris/kernel/ptrace.c	Fri Jul 20 01:02:51 2001
+++ linux/arch/cris/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -117,7 +117,7 @@
 	if (request == PTRACE_ATTACH) {
 		if (child == current)
 			goto out_tsk;
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		    (current->uid != child->euid) ||
 		    (current->uid != child->suid) ||
 		    (current->uid != child->uid) ||
diff -u --recursive --new-file pre9/linux/arch/i386/kernel/ptrace.c linux/arch/i386/kernel/ptrace.c
--- pre9/linux/arch/i386/kernel/ptrace.c	Fri Jul 20 01:02:52 2001
+++ linux/arch/i386/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -176,7 +176,7 @@
 	 	    (current->gid != child->gid)) && !capable(CAP_SYS_PTRACE))
 			goto out_tsk;
 		rmb();
-		if (!child->mm->dumpable && !capable(CAP_SYS_PTRACE))
+		if (!ptrace_dumpable(child) && !capable(CAP_SYS_PTRACE))
 			goto out_tsk;
 		/* the same process cannot be attached many times */
 		if (child->ptrace & PT_PTRACED)
diff -u --recursive --new-file pre9/linux/arch/ia64/kernel/ptrace.c linux/arch/ia64/kernel/ptrace.c
--- pre9/linux/arch/ia64/kernel/ptrace.c	Fri Jul 20 01:02:52 2001
+++ linux/arch/ia64/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -770,7 +770,7 @@
 	if (request == PTRACE_ATTACH) {
 		if (child == current)
 			goto out_tsk;
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		    (current->uid != child->euid) ||
 		    (current->uid != child->suid) ||
 		    (current->uid != child->uid) ||
diff -u --recursive --new-file pre9/linux/arch/m68k/kernel/ptrace.c linux/arch/m68k/kernel/ptrace.c
--- pre9/linux/arch/m68k/kernel/ptrace.c	Fri Jul 20 01:02:52 2001
+++ linux/arch/m68k/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -120,7 +120,7 @@
 	if (request == PTRACE_ATTACH) {
 		if (child == current)
 			goto out_tsk;
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		    (current->uid != child->euid) ||
 		    (current->uid != child->suid) ||
 		    (current->uid != child->uid) ||
diff -u --recursive --new-file pre9/linux/arch/mips/kernel/ptrace.c linux/arch/mips/kernel/ptrace.c
--- pre9/linux/arch/mips/kernel/ptrace.c	Fri Jul 20 01:02:52 2001
+++ linux/arch/mips/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -68,7 +68,7 @@
 	if (request == PTRACE_ATTACH) {
 		if (child == current)
 			goto out_tsk;
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		    (current->uid != child->euid) ||
 		    (current->uid != child->suid) ||
 		    (current->uid != child->uid) ||
diff -u --recursive --new-file pre9/linux/arch/mips64/kernel/ptrace.c linux/arch/mips64/kernel/ptrace.c
--- pre9/linux/arch/mips64/kernel/ptrace.c	Fri Jul 20 01:02:52 2001
+++ linux/arch/mips64/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -64,7 +64,7 @@
 	if (request == PTRACE_ATTACH) {
 		if (child == current)
 			goto out_tsk;
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		    (current->uid != child->euid) ||
 		    (current->uid != child->suid) ||
 		    (current->uid != child->uid) ||
@@ -338,7 +338,7 @@
 	if (request == PTRACE_ATTACH) {
 		if (child == current)
 			goto out_tsk;
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		    (current->uid != child->euid) ||
 		    (current->uid != child->suid) ||
 		    (current->uid != child->uid) ||
diff -u --recursive --new-file pre9/linux/arch/parisc/kernel/ptrace.c linux/arch/parisc/kernel/ptrace.c
--- pre9/linux/arch/parisc/kernel/ptrace.c	Fri Jul 20 01:02:52 2001
+++ linux/arch/parisc/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -63,7 +63,7 @@
 	if (request == PTRACE_ATTACH) {
 		if (child == current)
 			goto out_tsk;
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		    (current->uid != child->euid) ||
 		    (current->uid != child->suid) ||
 		    (current->uid != child->uid) ||
diff -u --recursive --new-file pre9/linux/arch/ppc/kernel/ptrace.c linux/arch/ppc/kernel/ptrace.c
--- pre9/linux/arch/ppc/kernel/ptrace.c	Fri Jul 20 01:02:53 2001
+++ linux/arch/ppc/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -120,7 +120,7 @@
 	if (request == PTRACE_ATTACH) {
 		if (child == current)
 			goto out_tsk;
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		    (current->uid != child->euid) ||
 		    (current->uid != child->suid) ||
 		    (current->uid != child->uid) ||
diff -u --recursive --new-file pre9/linux/arch/s390/kernel/ptrace.c linux/arch/s390/kernel/ptrace.c
--- pre9/linux/arch/s390/kernel/ptrace.c	Fri Jul 20 01:02:53 2001
+++ linux/arch/s390/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -235,7 +235,7 @@
 	{
 		if (child == current)
 			goto out;
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		     (current->uid != child->euid) ||
 		     (current->uid != child->suid) ||
 		     (current->uid != child->uid) ||
diff -u --recursive --new-file pre9/linux/arch/s390x/kernel/ptrace.c linux/arch/s390x/kernel/ptrace.c
--- pre9/linux/arch/s390x/kernel/ptrace.c	Fri Jul 20 01:02:53 2001
+++ linux/arch/s390x/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -249,7 +249,7 @@
 	{
 		if (child == current)
 			goto out;
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		     (current->uid != child->euid) ||
 		     (current->uid != child->suid) ||
 		     (current->uid != child->uid) ||
@@ -435,7 +435,7 @@
 	{
 		if (child == current)
 			goto out;
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		     (current->uid != child->euid) ||
 		     (current->uid != child->suid) ||
 		     (current->uid != child->uid) ||
diff -u --recursive --new-file pre9/linux/arch/sh/kernel/ptrace.c linux/arch/sh/kernel/ptrace.c
--- pre9/linux/arch/sh/kernel/ptrace.c	Fri Jul 20 01:02:53 2001
+++ linux/arch/sh/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -184,7 +184,7 @@
 	 	    (tsk->gid != child->gid)) && !capable(CAP_SYS_PTRACE))
 			goto out_tsk;
 		rmb();
-		if (!child->mm->dumpable && !capable(CAP_SYS_PTRACE))
+		if (!ptrace_dumpable(child) && !capable(CAP_SYS_PTRACE))
 			goto out_tsk;
 		/* the same process cannot be attached many times */
 		if (child->ptrace & PT_PTRACED)
diff -u --recursive --new-file pre9/linux/arch/sparc/kernel/ptrace.c linux/arch/sparc/kernel/ptrace.c
--- pre9/linux/arch/sparc/kernel/ptrace.c	Fri Jul 20 01:02:53 2001
+++ linux/arch/sparc/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -327,7 +327,7 @@
 			pt_error_return(regs, EPERM);
 			goto out_tsk;
 		}
-		if((!child->mm->dumpable ||
+		if((!ptrace_dumpable(child) ||
 		    (current->uid != child->euid) ||
 		    (current->uid != child->uid) ||
 		    (current->uid != child->suid) ||
diff -u --recursive --new-file pre9/linux/arch/sparc64/kernel/ptrace.c linux/arch/sparc64/kernel/ptrace.c
--- pre9/linux/arch/sparc64/kernel/ptrace.c	Fri Jul 20 01:02:54 2001
+++ linux/arch/sparc64/kernel/ptrace.c	Fri Jul 20 01:01:43 2001
@@ -177,7 +177,7 @@
 			pt_error_return(regs, EPERM);
 			goto out_tsk;
 		}
-		if ((!child->mm->dumpable ||
+		if ((!ptrace_dumpable(child) ||
 		     (current->uid != child->euid) ||
 		     (current->uid != child->uid) ||
 		     (current->uid != child->suid) ||
diff -u --recursive --new-file pre9/linux/fs/proc/base.c linux/fs/proc/base.c
--- pre9/linux/fs/proc/base.c	Fri Jul 20 01:03:03 2001
+++ linux/fs/proc/base.c	Fri Jul 20 00:59:38 2001
@@ -670,7 +670,7 @@
 	inode->u.proc_i.task = task;
 	inode->i_uid = 0;
 	inode->i_gid = 0;
-	if (ino == PROC_PID_INO || task->mm->dumpable) {
+	if (ino == PROC_PID_INO || ptrace_dumpable(task)) {
 		inode->i_uid = task->euid;
 		inode->i_gid = task->egid;
 	}
diff -u --recursive --new-file pre9/linux/include/linux/mm.h linux/include/linux/mm.h
--- pre9/linux/include/linux/mm.h	Tue Jul  3 15:42:55 2001
+++ linux/include/linux/mm.h	Fri Jul 20 00:59:22 2001
@@ -442,6 +442,7 @@
 extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
 extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char *dst, int len);
 extern int ptrace_writedata(struct task_struct *tsk, char * src, unsigned long dst, int len);
+extern int ptrace_dumpable(struct task_struct *tsk);

 /*
  * On a two-level page table, this ends up being trivial. Thus the
diff -u --recursive --new-file pre9/linux/kernel/ptrace.c linux/kernel/ptrace.c
--- pre9/linux/kernel/ptrace.c	Mon Mar 19 12:35:08 2001
+++ linux/kernel/ptrace.c	Fri Jul 20 00:58:46 2001
@@ -16,6 +16,19 @@
 #include <asm/pgtable.h>
 #include <asm/uaccess.h>

+int ptrace_dumpable(struct task_struct *task)
+{
+	int dumpable = 0;
+	struct mm_struct *mm;
+
+	task_lock(task);
+	mm = task->mm;
+	if (mm)
+		dumpable = mm->dumpable;
+	task_unlock(task);
+	return dumpable;
+}
+
 /*
  * Access another process' address space, one page at a time.
  */


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2001-07-20  8:11 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2001-07-20  6:16 Oops in 2.4.7-pre9 Niels Kristian Bech Jensen
2001-07-20  6:26 ` David S. Miller
2001-07-20  7:27   ` Niels Kristian Bech Jensen
2001-07-20  6:52 ` Andrew Morton
2001-07-20  8:10   ` Linus Torvalds

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