Re: input0: bad kobj_uevent_env content in show_uevent()
From: Fengguang Wu
Date: Sun Sep 02 2012 - 04:34:17 EST
It's more than the input device that can trigger the panic.
Here is another trace which panics on accessing dmi/id/uevent:
[ 32.380795] sysfs_read_file: /sys/devices/virtual/dmi/id/uevent
[ 32.399379] dmi id: uevent 73 env[1677721600]: id/.../id
[ 32.400780] uevent 0 env[0]: (null)
[ 32.401695] uevent 7 env[1]: (null)
...
[ 32.478415] general protection fault: 0000 [#1] PREEMPT
[ 32.479953] CPU 0
[ 32.480433] Pid: 114, comm: trinity-child0 Not tainted 3.6.0-rc4-bisect2-00001-gb6d86d3-dirty #26 Bochs Bochs
[ 32.482995] RIP: 0010:[<ffffffff81266c33>] [<ffffffff81266c33>] strnlen+0x23/0x70
...
[ 32.486234] Call Trace:
[ 32.486234] [<ffffffff81268d5c>] string.isra.4+0x4c/0x120
[ 32.486234] [<ffffffff81269f19>] vsnprintf+0x2c9/0x900
[ 32.486234] [<ffffffff8126a9c9>] vscnprintf+0x19/0x50
[ 32.486234] [<ffffffff8105f8c7>] vprintk_emit+0xe7/0x750
[ 32.486234] [<ffffffff81a49ba9>] printk+0x4f/0x58
[ 32.486234] [<ffffffff8150522b>] show_uevent+0x1cb/0x220
[ 32.486234] [<ffffffff81501dcb>] dev_attr_show+0x2b/0x90
[ 32.486234] [<ffffffff81174bea>] ? sysfs_read_file+0x18a/0x320
[ 32.486234] [<ffffffff810f2974>] ? __get_free_pages+0x24/0xc0
[ 32.486234] [<ffffffff81174c2d>] sysfs_read_file+0x1cd/0x320
Thanks,
Fengguang
On Sun, Sep 02, 2012 at 03:59:46PM +0800, Fengguang Wu wrote:
> Hi all,
>
> After the __devinit* removal series, I can still get kernel panic in
> show_uevent(). So there are more sources of bug..
>
> Debug patch:
>
> @@ -343,8 +343,11 @@ static ssize_t show_uevent(struct device
> goto out;
>
> /* copy keys to file */
> - for (i = 0; i < env->envp_idx; i++)
> + dev_err(dev, "uevent %d env[%d]: %s/.../%s\n", env->buflen, env->envp_idx, top_kobj->name, dev->kobj.name);
> + for (i = 0; i < env->envp_idx; i++) {
> + printk(KERN_ERR "uevent %d env[%d]: %s\n", (int)count, i, env->envp[i]);
> count += sprintf(&buf[count], "%s\n", env->envp[i]);
> + }
>
> Oops message, the env[] is again not properly initilized:
>
> [ 44.068623] input input0: uevent 61 env[805306368]: input0/.../input0
> [ 44.069552] uevent 0 env[0]: (null)
> [ 44.070107] uevent 7 env[1]: (null)
> [ 44.070609] uevent 14 env[2]: (null)
> [ 44.071136] uevent 21 env[3]: (null)
> [ 44.071637] uevent 28 env[4]: (null)
> [ 44.072166] uevent 35 env[5]: (null)
> [ 44.072674] uevent 42 env[6]: (null)
> [ 44.073188] uevent 49 env[7]: (null)
> [ 44.073694] uevent 56 env[8]: (null)
> [ 44.074207] uevent 63 env[9]: (null)
> [ 44.074709] uevent 70 env[10]: (null)
> [ 44.075235] uevent 77 env[11]: (null)
> [ 44.075748] uevent 84 env[12]: (null)
> [ 44.076270] uevent 91 env[13]: (null)
> [ 44.076783] uevent 98 env[14]: (null)
> [ 44.077310] uevent 105 env[15]: (null)
> [ 44.077843] uevent 112 env[16]: (null)
> [ 44.078384] uevent 119 env[17]: (null)
> [ 44.078911] uevent 126 env[18]: (null)
> [ 44.079451] uevent 133 env[19]: (null)
> [ 44.079979] uevent 140 env[20]: (null)
> [ 44.080537] uevent 147 env[21]: (null)
> [ 44.081077] uevent 154 env[22]: (null)
> [ 44.081614] uevent 161 env[23]: (null)
> [ 44.082151] uevent 168 env[24]: (null)
> [ 44.082680] uevent 175 env[25]: (null)
> [ 44.083217] uevent 182 env[26]: (null)
> [ 44.083740] uevent 189 env[27]: (null)
> [ 44.084282] uevent 196 env[28]: (null)
> [ 44.084810] uevent 203 env[29]: (null)
> [ 44.085350] uevent 210 env[30]: (null)
> [ 44.085889] uevent 217 env[31]: (null)
> [ 44.086434] general protection fault: 0000 [#1] PREEMPT
> [ 44.087232] CPU 0
> [ 44.087505] Pid: 135, comm: trinity-child0 Not tainted 3.6.0-rc4-bisect2-00001-gb6d86d3-dirty #25 Bochs Bochs
> [ 44.088928] RIP: 0010:[<ffffffff81266ba3>] [<ffffffff81266ba3>] strnlen+0x23/0x70
> [ 44.090037] RSP: 0018:ffff8800073dfc58 EFLAGS: 00010006
> [ 44.090522] RAX: ffff8800073dfe00 RBX: ffffffff8291f0f6 RCX: 000000000001c66a
> [ 44.090522] RDX: 3030313330000000 RSI: ffffffffffffffff RDI: 3030313330000000
> [ 44.090522] RBP: ffff8800073dfc58 R08: 000000000000ffff R09: 000000000000ffff
> [ 44.090522] R10: 0000000000000001 R11: 0000000000000001 R12: 3030313330000000
> [ 44.090522] R13: ffffffff8291f4c0 R14: 000000000000ffff R15: 0000000000000000
> [ 44.090522] FS: 00007ff846958700(0000) GS:ffffffff8222d000(0000) knlGS:0000000000000000
> [ 44.090522] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [ 44.090522] CR2: 00000000030e5000 CR3: 00000000073ee000 CR4: 00000000000006b0
> [ 44.090522] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [ 44.090522] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> [ 44.090522] Process trinity-child0 (pid: 135, threadinfo ffff8800073de000, task ffff880006c0c000)
> [ 44.090522] Stack:
> [ 44.090522] ffff8800073dfc98 ffffffff81268ccc ffffffff82252f18 ffffffff81faf19e
> [ 44.090522] ffffffff8291f4c0 ffff8800073dfdd0 ffffffff81faf19e ffffffff8291f0f6
> [ 44.090522] ffff8800073dfd18 ffffffff81269e89 ffffffff82250002 ffffffff82252ea0
> [ 44.090522] Call Trace:
> [ 44.090522] [<ffffffff81268ccc>] string.isra.4+0x4c/0x120
> [ 44.090522] [<ffffffff81269e89>] vsnprintf+0x2c9/0x900
> [ 44.090522] [<ffffffff8126a939>] vscnprintf+0x19/0x50
> [ 44.090522] [<ffffffff8105f8c7>] vprintk_emit+0xe7/0x750
> [ 44.090522] [<ffffffff81a49b19>] printk+0x4f/0x58
> [ 44.090522] [<ffffffff8150519b>] show_uevent+0x1cb/0x220
> [ 44.090522] [<ffffffff81501d3b>] dev_attr_show+0x2b/0x90
> [ 44.090522] [<ffffffff81174b72>] ? sysfs_read_file+0x112/0x290
> [ 44.090522] [<ffffffff810f2974>] ? __get_free_pages+0x24/0xc0
> [ 44.090522] [<ffffffff81174bae>] sysfs_read_file+0x14e/0x290
> [ 44.090522] [<ffffffff81125b07>] vfs_read+0xc7/0x200
> [ 44.090522] [<ffffffff81125fa0>] sys_read+0x60/0xd0
> [ 44.090522] [<ffffffff81a5d737>] system_call_fastpath+0x16/0x1b
>
> Thanks,
> Fengguang
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