diff options
| author | Bruno Prémont <bonbons@linux-vserver.org> | 2012-04-03 09:59:48 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-04-10 14:48:51 -0700 |
| commit | 5631f2c18f4b2845b3e97df1c659c5094a17605f (patch) | |
| tree | 1d9ab2d5dd8b694ae8a2074a96e7c548ffc6bd3e | |
| parent | 70fa4a62e913dde2d100e0be2711562742f58bee (diff) | |
sysfs: Prevent crash on unset sysfs group attributes
Do not let the kernel crash when a device is registered with
sysfs while group attributes are not set (aka NULL).
Warn about the offender with some information about the offending
device.
This would warn instead of trying NULL pointer deref like:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff81152673>] internal_create_group+0x83/0x1a0
PGD 0
Oops: 0000 [#1] SMP
CPU 0
Modules linked in:
Pid: 1, comm: swapper/0 Not tainted 3.4.0-rc1-x86_64 #3 HP ProLiant DL360 G4
RIP: 0010:[<ffffffff81152673>] [<ffffffff81152673>] internal_create_group+0x83/0x1a0
RSP: 0018:ffff88019485fd70 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000001
RDX: ffff880192e99908 RSI: ffff880192e99630 RDI: ffffffff81a26c60
RBP: ffff88019485fdc0 R08: 0000000000000000 R09: 0000000000000000
R10: ffff880192e99908 R11: 0000000000000000 R12: ffffffff81a16a00
R13: ffff880192e99908 R14: ffffffff81a16900 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88019bc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000000 CR3: 0000000001a0c000 CR4: 00000000000007f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper/0 (pid: 1, threadinfo ffff88019485e000, task ffff880194878000)
Stack:
ffff88019485fdd0 ffff880192da9d60 0000000000000000 ffff880192e99908
ffff880192e995d8 0000000000000001 ffffffff81a16a00 ffff880192da9d60
0000000000000000 0000000000000000 ffff88019485fdd0 ffffffff811527be
Call Trace:
[<ffffffff811527be>] sysfs_create_group+0xe/0x10
[<ffffffff81376ca6>] device_add_groups+0x46/0x80
[<ffffffff81377d3d>] device_add+0x46d/0x6a0
...
Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/sysfs/group.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index dd1701caecc..2df555c66d5 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -67,7 +67,11 @@ static int internal_create_group(struct kobject *kobj, int update, /* Updates may happen before the object has been instantiated */ if (unlikely(update && !kobj->sd)) return -EINVAL; - + if (!grp->attrs) { + WARN(1, "sysfs: attrs not set by subsystem for group: %s/%s\n", + kobj->name, grp->name ? "" : grp->name); + return -EINVAL; + } if (grp->name) { error = sysfs_create_subdir(kobj, grp->name, &sd); if (error) |