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@xxxxxxxxxxxx> > Link: https://lore.kernel.org/platform-driver-x86/01e920bc-5882-ba0c-dd15-868bf0eca0b8@xxxxxxxxxxxx/T/#t > Fixes: a40cd7ef22fb ("platform/x86: think-lmi: Add WMI interface support on Lenovo platforms") > Signed-off-by: Armin Wolf <W_Armin@xxxxxx> > --- > 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@xxxxxxxxxxxx>. 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@xxxxxxxxxxxx> 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 -- Mirsad Goran Todorovac Sistem inženjer Grafički fakultet | Akademija likovnih umjetnosti Sveučilište u Zagrebu System engineer Faculty of Graphic Arts | Academy of Fine Arts University of Zagreb, Republic of Croatia The European Union "I see something approaching fast ... Will it be friends with me?"
