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author | Chen Zhongjin <chenzhongjin@huawei.com> | 2022-11-11 04:53:26 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-10 11:33:34 +0300 |
commit | e851996b32264e78a10863c2ac41a8689d7b9252 (patch) | |
tree | 76bbeaa8995d254dee471fec2f9187bdad8414e8 /drivers/firmware | |
parent | 29274780dda029223392314da63f0a30eeadd874 (diff) | |
download | linux-e851996b32264e78a10863c2ac41a8689d7b9252.tar.xz |
firmware: dmi-sysfs: Fix null-ptr-deref in dmi_sysfs_register_handle
[ Upstream commit 18e126e97c961f7a93823795c879d7c085fe5098 ]
KASAN reported a null-ptr-deref error:
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 PID: 1373 Comm: modprobe
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
RIP: 0010:dmi_sysfs_entry_release
...
Call Trace:
<TASK>
kobject_put
dmi_sysfs_register_handle (drivers/firmware/dmi-sysfs.c:540) dmi_sysfs
dmi_decode_table (drivers/firmware/dmi_scan.c:133)
dmi_walk (drivers/firmware/dmi_scan.c:1115)
dmi_sysfs_init (drivers/firmware/dmi-sysfs.c:149) dmi_sysfs
do_one_initcall (init/main.c:1296)
...
Kernel panic - not syncing: Fatal exception
Kernel Offset: 0x4000000 from 0xffffffff81000000
---[ end Kernel panic - not syncing: Fatal exception ]---
It is because previous patch added kobject_put() to release the memory
which will call dmi_sysfs_entry_release() and list_del().
However, list_add_tail(entry->list) is called after the error block,
so the list_head is uninitialized and cannot be deleted.
Move error handling to after list_add_tail to fix this.
Fixes: 660ba678f999 ("firmware: dmi-sysfs: Fix memory leak in dmi_sysfs_register_handle")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Link: https://lore.kernel.org/r/20221111015326.251650-2-chenzhongjin@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/firmware')
-rw-r--r-- | drivers/firmware/dmi-sysfs.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c index 66727ad3361b..402217c57033 100644 --- a/drivers/firmware/dmi-sysfs.c +++ b/drivers/firmware/dmi-sysfs.c @@ -603,16 +603,16 @@ static void __init dmi_sysfs_register_handle(const struct dmi_header *dh, *ret = kobject_init_and_add(&entry->kobj, &dmi_sysfs_entry_ktype, NULL, "%d-%d", dh->type, entry->instance); - if (*ret) { - kobject_put(&entry->kobj); - return; - } - /* Thread on the global list for cleanup */ spin_lock(&entry_list_lock); list_add_tail(&entry->list, &entry_list); spin_unlock(&entry_list_lock); + if (*ret) { + kobject_put(&entry->kobj); + return; + } + /* Handle specializations by type */ switch (dh->type) { case DMI_ENTRY_SYSTEM_EVENT_LOG: |