Re: [patch -mm] alsa mixer_oss kfree fix

["young dave" <hidave.darkstar@gmail.com>]

Hi,
Just append to my email.

The reason I read mixer_oss.c is that I see oops in 2.6.22-rc1-mm1,
seems oops in mixer_oss.c, but the oops rised only once, I found
rc3-mm1 have no change in this file,
so I read the source , then post this patch.

please find the oops message below:


BUG: unable to handle kernel NULL pointer dereference at virtual
address 00000088
printing eip:
c0162bc2
*pde = 00000000
Oops: 0000 [#1]
PREEMPT
Modules linked in: snd_mixer_oss snd_hda_intel snd_pcm snd_timer
snd_page_alloc snd soundcore ipv6 capability commoncap e100 mi
i agpgart pcspkr psmouse
CPU:    0
EIP:    0060:[<c0162bc2>]    Not tainted VLI
EFLAGS: 00010087   (2.6.22-rc1-mm1 #7)
EIP is at kfree+0x42/0x90
eax: 00000000   ebx: c10568e0   ecx: c2b47000   edx: c01588d2
esi: 00000287   edi: 00000000   ebp: c2864000   esp: c2865f58
ds: 007b   es: 007b   fs: 0000  gs: 0033  ss: 0068
Process modprobe (pid: 2963, ti=c2864000 task=c1ede540 task.ti=c2864000)
Stack: 00000011 f8855000 c0520cb4 00000001 00000001 c1e524a0 c1051bc0 c01588d2
      0805c348 00000001 c2864000 f885502b f8840a00 00000000 00000001 c013caf1
      00004b79 00000000 000b7f68 00000000 b7f44840 08065f88 0805c348 c01040bc
Call Trace:
[<f8855000>] alsa_mixer_oss_init+0x0/0x37 [snd_mixer_oss]
[<c01588d2>] __vunmap+0xb2/0xe0
[<f885502b>] alsa_mixer_oss_init+0x2b/0x37 [snd_mixer_oss]
[<c013caf1>] sys_init_module+0xa1/0x140
[<c01040bc>] syscall_call+0x7/0xb
[<c0440000>] packet_seq_start+0x30/0x60
=======================
Code: 00 00 00 40 a1 40 6a 59 c0 c1 ea 0c c1 e2 05 01 c2 8b 02 89 d3
25 00 40 02 00 3d 00 40 02 00 74 45 8b 7b 10 8b 54 24 1c 9
c 5e fa <39> 9f 88 00 00 00 75 25 8b 03 a8 02 75 1f 0f b7 53 0a 8b 43 0c
EIP: [<c0162bc2>] kfree+0x42/0x90 SS:ESP 0068:c2865f58
-
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/