Messages in this thread | | | Subject | Re: [PATCH v2] platform/x86: think-lmi: Fix memory leak when showing current settings | From | Armin Wolf <> | Date | Fri, 31 Mar 2023 23:30:15 +0200 |
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Am 31.03.23 um 22:23 schrieb Mirsad Goran Todorovac:
> On 31. 03. 2023. 20:09, Armin Wolf wrote: >> When retriving a item string with tlmi_setting(), the result has to be >> freed using kfree(). In current_value_show() however, malformed >> item strings are not freed, causing a memory leak. >> Fix this by eliminating the early return responsible for this. >> >> Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr> >> Link: https://lore.kernel.org/platform-driver-x86/01e920bc-5882-ba0c-dd15-868bf0eca0b8@alu.unizg.hr/T/#t >> Fixes: a40cd7ef22fb ("platform/x86: think-lmi: Add WMI interface support on Lenovo platforms") >> Signed-off-by: Armin Wolf <W_Armin@gmx.de> >> --- >> Changes in v2: >> - Add Reported-by: and Link: tags >> --- >> drivers/platform/x86/think-lmi.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/platform/x86/think-lmi.c b/drivers/platform/x86/think-lmi.c >> index cc66f7cbccf2..8cafb9d4016c 100644 >> --- a/drivers/platform/x86/think-lmi.c >> +++ b/drivers/platform/x86/think-lmi.c >> @@ -930,10 +930,12 @@ static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *a >> /* validate and split from `item,value` -> `value` */ >> value = strpbrk(item, ","); >> if (!value || value == item || !strlen(value + 1)) >> - return -EINVAL; >> + ret = -EINVAL; >> + else >> + ret = sysfs_emit(buf, "%s\n", value + 1); >> >> - ret = sysfs_emit(buf, "%s\n", value + 1); >> kfree(item); >> + >> return ret; >> } >> >> -- >> 2.30.2 > I can confirm that the test passed in the original environment that caused the kmemleak. > > [root@pc-mtodorov marvin]# cat /sys/kernel/debug/kmemleak > unreferenced object 0xffff8e614889e390 (size 16): > comm "kworker/u12:5", pid 366, jiffies 4294896428 (age 93.704s) > hex dump (first 16 bytes): > 6d 65 6d 73 74 69 63 6b 30 00 cc cc cc cc cc cc memstick0....... > backtrace: > [<ffffffff860fb26c>] slab_post_alloc_hook+0x8c/0x3e0 > [<ffffffff86102b49>] __kmem_cache_alloc_node+0x1d9/0x2a0 > [<ffffffff860773c9>] __kmalloc_node_track_caller+0x59/0x180 > [<ffffffff86066a1a>] kstrdup+0x3a/0x70 > [<ffffffff86066a8c>] kstrdup_const+0x2c/0x40 > [<ffffffff864a987c>] kvasprintf_const+0x7c/0xb0 > [<ffffffff86e3b427>] kobject_set_name_vargs+0x27/0xa0 > [<ffffffff8678ed17>] dev_set_name+0x57/0x80 > [<ffffffffc0e49f0f>] memstick_check+0x10f/0x3b0 [memstick] > [<ffffffff85dcb4c0>] process_one_work+0x250/0x530 > [<ffffffff85dcb7f8>] worker_thread+0x48/0x3a0 > [<ffffffff85dd6dff>] kthread+0x10f/0x140 > [<ffffffff85c02fa9>] ret_from_fork+0x29/0x50 > unreferenced object 0xffff8e6158f93b90 (size 16): > comm "kworker/u12:5", pid 366, jiffies 4294896433 (age 93.684s) > hex dump (first 16 bytes): > 6d 65 6d 73 74 69 63 6b 30 00 cc cc cc cc cc cc memstick0....... > backtrace: > [<ffffffff860fb26c>] slab_post_alloc_hook+0x8c/0x3e0 > [<ffffffff86102b49>] __kmem_cache_alloc_node+0x1d9/0x2a0 > [<ffffffff860773c9>] __kmalloc_node_track_caller+0x59/0x180 > [<ffffffff86066a1a>] kstrdup+0x3a/0x70 > [<ffffffff86066a8c>] kstrdup_const+0x2c/0x40 > [<ffffffff864a987c>] kvasprintf_const+0x7c/0xb0 > [<ffffffff86e3b427>] kobject_set_name_vargs+0x27/0xa0 > [<ffffffff8678ed17>] dev_set_name+0x57/0x80 > [<ffffffffc0e49f0f>] memstick_check+0x10f/0x3b0 [memstick] > [<ffffffff85dcb4c0>] process_one_work+0x250/0x530 > [<ffffffff85dcb7f8>] worker_thread+0x48/0x3a0 > [<ffffffff85dd6dff>] kthread+0x10f/0x140 > [<ffffffff85c02fa9>] ret_from_fork+0x29/0x50 > [root@pc-mtodorov marvin]# uname -rms > Linux 6.3.0-rc4-00034-gfcd476ea6a88-dirty x86_64 > [root@pc-mtodorov marvin]# > > NOTE: The leaks here belong to drivers/memstick/core/memstick.c leak for which I have > proposed a fix in message <df560535-2a8e-de21-d45d-805159d70954@alu.unizg.hr>. > > This test was built on the 6.3-rc4+ commit fcd476ea6a88 Torvalds tree + the following > patches (Armin's, and Thomas's). > > drivers/platform/x86/think-lmi.c | 18 ++++++++++-------- > drivers/usb/host/xhci.c | 1 + > 2 files changed, 11 insertions(+), 8 deletions(-) > > diff --git a/drivers/platform/x86/think-lmi.c b/drivers/platform/x86/think-lmi.c > index c816646eb661..c2146add88ab 100644 > --- a/drivers/platform/x86/think-lmi.c > +++ b/drivers/platform/x86/think-lmi.c > @@ -930,10 +930,12 @@ static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *a > /* validate and split from `item,value` -> `value` */ > value = strpbrk(item, ","); > if (!value || value == item || !strlen(value + 1)) > - return -EINVAL; > + ret = -EINVAL; > + else > + ret = sysfs_emit(buf, "%s\n", value + 1); > > - ret = sysfs_emit(buf, "%s\n", value + 1); > kfree(item); > + > return ret; > } > > @@ -1380,7 +1382,6 @@ static struct tlmi_pwd_setting *tlmi_create_auth(const char *pwd_type, > > static int tlmi_analyze(void) > { > - acpi_status status; > int i, ret; > > if (wmi_has_guid(LENOVO_SET_BIOS_SETTINGS_GUID) && > @@ -1417,8 +1418,8 @@ static int tlmi_analyze(void) > char *p; > > tlmi_priv.setting[i] = NULL; > - status = tlmi_setting(i, &item, LENOVO_BIOS_SETTING_GUID); > - if (ACPI_FAILURE(status)) > + ret = tlmi_setting(i, &item, LENOVO_BIOS_SETTING_GUID); > + if (ret) > break; > if (!item) > break; > @@ -1457,10 +1458,10 @@ static int tlmi_analyze(void) > * name string. > * Try and pull that out if it's available. > */ > - char *item, *optstart, *optend; > + char *optitem, *optstart, *optend; > > - if (!tlmi_setting(setting->index, &item, LENOVO_BIOS_SETTING_GUID)) { > - optstart = strstr(item, "[Optional:"); > + if (!tlmi_setting(setting->index, &optitem, LENOVO_BIOS_SETTING_GUID)) { > + optstart = strstr(optitem, "[Optional:"); > if (optstart) { > optstart += strlen("[Optional:"); > optend = strstr(optstart, "]"); > @@ -1469,6 +1470,7 @@ static int tlmi_analyze(void) > kstrndup(optstart, optend - optstart, > GFP_KERNEL); > } > + kfree(optitem); > } > } > /* > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c > index 6183ce8574b1..905f1e89ead8 100644 > --- a/drivers/usb/host/xhci.c > +++ b/drivers/usb/host/xhci.c > @@ -4438,6 +4438,7 @@ static int __maybe_unused xhci_change_max_exit_latency(struct xhci_hcd *xhci, > > if (!virt_dev || max_exit_latency == virt_dev->current_mel) { > spin_unlock_irqrestore(&xhci->lock, flags); > + xhci_free_command(xhci, command); > return 0; > } > > Xhci patch from Mathias is included because it is well tested and already submitted and acked. > > At your convenience and according to the Code of Conduct, you can add: > > Tested-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr> > > Otherwise, Armin, I think you should submit this patch rightly because all idea to search in > think-lmi.c was yours. > > Bisect was also much faster and in fewer steps. > > Thanks, > Mirsad > Thank you for reporting the memory leak issues and testing the patches. I will send a v3 of my patch soon which will contain your Tested-by: tag.
Armin Wolf
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