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| author | Yang Yingliang <yangyingliang@huawei.com> | 2022-10-26 11:28:03 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-11-09 16:58:29 +0300 |
| commit | 8c3e8a6bdb5253b97ad532570f8b5db5f7a06407 (patch) | |
| tree | 19a12897d906066482178a2f333a672fc58c3b26 /drivers/base | |
| parent | 1662cea4623f75d8251adf07370bbaa958f0355d (diff) | |
| download | linux-8c3e8a6bdb5253b97ad532570f8b5db5f7a06407.tar.xz | |
class: fix possible memory leak in __class_register()
If class_add_groups() returns error, the 'cp->subsys' need be
unregister, and the 'cp' need be freed.
We can not call kset_unregister() here, because the 'cls' will
be freed in callback function class_release() and it's also
freed in caller's error path, it will cause double free.
So fix this by calling kobject_del() and kfree_const(name) to
cleanup kobject. Besides, call kfree() to free the 'cp'.
Fault injection test can trigger this:
unreferenced object 0xffff888102fa8190 (size 8):
comm "modprobe", pid 502, jiffies 4294906074 (age 49.296s)
hex dump (first 8 bytes):
70 6b 74 63 64 76 64 00 pktcdvd.
backtrace:
[<00000000e7c7703d>] __kmalloc_track_caller+0x1ae/0x320
[<000000005e4d70bc>] kstrdup+0x3a/0x70
[<00000000c2e5e85a>] kstrdup_const+0x68/0x80
[<000000000049a8c7>] kvasprintf_const+0x10b/0x190
[<0000000029123163>] kobject_set_name_vargs+0x56/0x150
[<00000000747219c9>] kobject_set_name+0xab/0xe0
[<0000000005f1ea4e>] __class_register+0x15c/0x49a
unreferenced object 0xffff888037274000 (size 1024):
comm "modprobe", pid 502, jiffies 4294906074 (age 49.296s)
hex dump (first 32 bytes):
00 40 27 37 80 88 ff ff 00 40 27 37 80 88 ff ff .@'7.....@'7....
00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
backtrace:
[<00000000151f9600>] kmem_cache_alloc_trace+0x17c/0x2f0
[<00000000ecf3dd95>] __class_register+0x86/0x49a
Fixes: ced6473e7486 ("driver core: class: add class_groups support")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221026082803.3458760-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/class.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/base/class.c b/drivers/base/class.c index 64f7b9a0970f..8ceafb7d0203 100644 --- a/drivers/base/class.c +++ b/drivers/base/class.c @@ -192,6 +192,11 @@ int __class_register(struct class *cls, struct lock_class_key *key) } error = class_add_groups(class_get(cls), cls->class_groups); class_put(cls); + if (error) { + kobject_del(&cp->subsys.kobj); + kfree_const(cp->subsys.kobj.name); + kfree(cp); + } return error; } EXPORT_SYMBOL_GPL(__class_register); |