2.4.19 Oops :Unable to handle kernel paging request

From: Johan Martensson (a0087901@levonline.com)
Date: Fri Aug 09 2002 - 07:17:22 EST


Hi all,
One of our machines running linux 2.4.19 with grsecurity 1.9.6 got an Oops
last night. I'm sorry if it is obvious that this is caused by grsecurity
and wouldn't happen with vanilla 2.4.19 (I'm too stupid to tell:)).

The machine has been running without any problems since May using various
kernels. Since early July using 2.4.19-rc1/grsec 1.9.5. A few hours after
upgrading to 2.4.19/grsec 1.9.6 we got the Oops. I haven't been able to
reproduce it. When it happend the system was pretty much idle.

Any help on how to find or reproduce the oops is much appreciated.

Below is at least some relevant information.
Please cc replies to me since I'm not subscribed to lkml for the moment.

Thanks,
 Johan

The hardware is a HP rc7100 4-way XEON with 2 gigs of ram.

#lsmod
Module Size Used by Not tainted
e1000 65020 1
eepro100 17808 1
st 27476 0 (unused)
aic7xxx 120480 0 (unused)
lpfcdd 224104 8
megaraid 24800 9

(swap is on megaraid).

sar -r output.
12:00:00 AM kbmemfree kbmemused %memused kbmemshrd kbbuffers kbcached
kbswpfree kbswpused %swpused
12:04:00 AM 7020 2062752 99.66 0 124600 1765060
1946212 102036 4.98
12:05:00 AM 6964 2062808 99.66 0 124948 1764728
1946128 102120 4.99
12:06:00 AM 18648 2051124 99.10 0 125500 1758728
1944448 103800 5.07
12:07:00 AM 18360 2051412 99.11 0 125856 1758736
1944448 103800 5.07

klogd/ksymops:
Aug 9 00:05:50 dpluplu3 kernel: Unable to handle kernel paging request at
virtual address 00200044
Aug 9 00:05:50 dpluplu3 kernel: c024cfe0
Aug 9 00:05:50 dpluplu3 kernel: *pde = 00000000
Aug 9 00:05:50 dpluplu3 kernel: Oops: 0000
Aug 9 00:05:50 dpluplu3 kernel: CPU: 1
Aug 9 00:05:50 dpluplu3 kernel: EIP: 0010:[gr_check_create+448/832]
Not tainted
Aug 9 00:05:50 dpluplu3 kernel: EIP: 0010:[<c024cfe0>] Not tainted
Using defaults from ksymoops -t elf32-i386 -a i386
Aug 9 00:05:50 dpluplu3 kernel: EFLAGS: 00010206
Aug 9 00:05:50 dpluplu3 kernel: eax: 0000002f ebx: c4c4aff0 ecx:
f89f46d0 edx: 00200044
Aug 9 00:05:50 dpluplu3 kernel: esi: c4c4aff1 edi: 00200044 ebp:
0000033c esp: f2445ed0
Aug 9 00:05:50 dpluplu3 kernel: ds: 0018 es: 0018 ss: 0018
Aug 9 00:05:50 dpluplu3 kernel: Process dbsnmp (pid: 1084,
stackpage=f2445000)
Aug 9 00:05:54 dpluplu3 kernel: Stack: c014a0be f7f49790 f26ac005
0e01899f c4c4a000 00001000 00000005 f2445f8c
Aug 9 00:05:54 dpluplu3 kernel: f770e380 c01491e0 c283ba00
f2445f8c 00000000 c014a59a c283ba00 c283ba00
Aug 9 00:05:54 dpluplu3 kernel: da00ca00 c283ba00 00000243
c014abe8 da00ca00 c283ba00 f7bb2e80 00000005
Aug 9 00:05:54 dpluplu3 kernel: Call Trace: [link_path_walk+3198/3536]
[cached_lookup+16/80] [lookup_hash+74/208] [open_namei+1048/2912]
[filp_open+54/96]
Aug 9 00:05:54 dpluplu3 kernel: Call Trace: [<c014a0be>] [<c01491e0>]
[<c014a59a>] [<c014abe8>] [<c013dc26>]
Aug 9 00:05:54 dpluplu3 kernel: [<c013df74>] [<c0108c3b>]
Aug 9 00:05:54 dpluplu3 kernel: Code: ae 75 08 84 c0 75 f8 31 c0 eb 04 19
c0 0c 01 85 c0 74 02 31

>>EIP; c024cfe0 <gr_check_create+1c0/340> <=====
Trace; c014a0be <link_path_walk+c7e/dd0>
Trace; c01491e0 <cached_lookup+10/50>
Trace; c014a59a <lookup_hash+4a/d0>
Trace; c014abe8 <open_namei+418/b60>
Trace; c013dc26 <filp_open+36/60>
Trace; c013df74 <sys_open+34/a0>
Trace; c0108c3b <system_call+33/38>
Code; c024cfe0 <gr_check_create+1c0/340>
00000000 <_EIP>:
Code; c024cfe0 <gr_check_create+1c0/340> <=====
   0: ae scas %es:(%edi),%al <=====
Code; c024cfe1 <gr_check_create+1c1/340>
   1: 75 08 jne b <_EIP+0xb> c024cfeb
<gr_check_create+1cb/340>
Code; c024cfe3 <gr_check_create+1c3/340>
   3: 84 c0 test %al,%al
Code; c024cfe5 <gr_check_create+1c5/340>
   5: 75 f8 jne ffffffff <_EIP+0xffffffff>
c024cfdf <gr_check_create+1bf/340>
Code; c024cfe7 <gr_check_create+1c7/340>
   7: 31 c0 xor %eax,%eax
Code; c024cfe9 <gr_check_create+1c9/340>
   9: eb 04 jmp f <_EIP+0xf> c024cfef
<gr_check_create+1cf/340>
Code; c024cfeb <gr_check_create+1cb/340>
   b: 19 c0 sbb %eax,%eax
Code; c024cfed <gr_check_create+1cd/340>
   d: 0c 01 or $0x1,%al
Code; c024cfef <gr_check_create+1cf/340>
   f: 85 c0 test %eax,%eax
Code; c024cff1 <gr_check_create+1d1/340>
  11: 74 02 je 15 <_EIP+0x15> c024cff5
<gr_check_create+1d5/340>
Code; c024cff3 <gr_check_create+1d3/340>
  13: 31 00 xor %eax,(%eax)

The c code from linux/grsecurity/gracl.c

int
gr_check_create(struct dentry *new_dentry, struct dentry *parent,
                struct vfsmount *mnt, __u16 mode)
{
        struct name_entry *match;
        struct acl_object_label *matchpo;
        int retval = GR_NOTFOUND;
        char *buffer;
        char *pathname;

        if (!(gr_status & GR_READY))
                return mode;

        buffer = (char *) get_free_page(GFP_KERNEL);
        if (!buffer)
                return 0; /* OOM : can't let anything get through */

        pathname = d_path(new_dentry, mnt, buffer, PAGE_SIZE);
.......

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Thu Aug 15 2002 - 22:00:19 EST