From: Wang Hai <wanghai38@huawei.com> To: <gregkh@linuxfoundation.org>, <alice.chao@mediatek.com>, <rafael@kernel.org>, <jesse.brandeburg@intel.com>, <anthony.l.nguyen@intel.com> Cc: intel-wired-lan@lists.osuosl.org, linux-kernel@vger.kernel.org Subject: [Intel-wired-lan] [PATCH v2] kobject: Fix slab-out-of-bounds in fill_kobj_path() Date: Tue, 20 Dec 2022 09:21:43 +0800 [thread overview] Message-ID: <20221220012143.52141-1-wanghai38@huawei.com> (raw) In kobject_get_path(), if kobj->name is changed between calls get_kobj_path_length() and fill_kobj_path() and the length becomes longer, then fill_kobj_path() will have an out-of-bounds bug. The actual current problem occurs when the ixgbe probe. In ixgbe_mii_bus_init(), if the length of netdev->dev.kobj.name length becomes longer, out-of-bounds will occur. cpu0 cpu1 ixgbe_probe register_netdev(netdev) netdev_register_kobject device_add kobject_uevent // Sending ADD events systemd-udevd // rename netdev dev_change_name device_rename kobject_rename ixgbe_mii_bus_init | mdiobus_register | __mdiobus_register | device_register | device_add | kobject_uevent | kobject_get_path | len = get_kobj_path_length // old name | path = kzalloc(len, gfp_mask); | kobj->name = name; /* name length becomes * longer */ fill_kobj_path /* kobj path length is * longer than path, * resulting in out of * bounds when filling path */ This is the kasan report: ================================================================== BUG: KASAN: slab-out-of-bounds in fill_kobj_path+0x50/0xc0 Write of size 7 at addr ff1100090573d1fd by task kworker/28:1/673 Workqueue: events work_for_cpu_fn Call Trace: <TASK> dump_stack_lvl+0x34/0x48 print_address_description.constprop.0+0x86/0x1e7 print_report+0x36/0x4f kasan_report+0xad/0x130 kasan_check_range+0x35/0x1c0 memcpy+0x39/0x60 fill_kobj_path+0x50/0xc0 kobject_get_path+0x5a/0xc0 kobject_uevent_env+0x140/0x460 device_add+0x5c7/0x910 __mdiobus_register+0x14e/0x490 ixgbe_probe.cold+0x441/0x574 [ixgbe] local_pci_probe+0x78/0xc0 work_for_cpu_fn+0x26/0x40 process_one_work+0x3b6/0x6a0 worker_thread+0x368/0x520 kthread+0x165/0x1a0 ret_from_fork+0x1f/0x30 This reproducer triggers that bug: while: do rmmod ixgbe sleep 0.5 modprobe ixgbe sleep 0.5 When calling fill_kobj_path() to fill path, if the name length of kobj becomes longer, return failure and retry. This fixes the problem. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Wang Hai <wanghai38@huawei.com> --- v1->v2: Return value type change and some formatting adjustments. lib/kobject.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/lib/kobject.c b/lib/kobject.c index a0b2dbfcfa23..3f97d903266a 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -112,7 +112,7 @@ static int get_kobj_path_length(struct kobject *kobj) return length; } -static void fill_kobj_path(struct kobject *kobj, char *path, int length) +static int fill_kobj_path(struct kobject *kobj, char *path, int length) { struct kobject *parent; @@ -121,12 +121,16 @@ static void fill_kobj_path(struct kobject *kobj, char *path, int length) int cur = strlen(kobject_name(parent)); /* back up enough to print this name with '/' */ length -= cur; + if (length <= 0) + return -EINVAL; memcpy(path + length, kobject_name(parent), cur); *(path + --length) = '/'; } pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj), kobj, __func__, path); + + return 0; } /** @@ -141,13 +145,17 @@ char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask) char *path; int len; +retry: len = get_kobj_path_length(kobj); if (len == 0) return NULL; path = kzalloc(len, gfp_mask); if (!path) return NULL; - fill_kobj_path(kobj, path, len); + if (fill_kobj_path(kobj, path, len)) { + kfree(path); + goto retry; + } return path; } -- 2.17.1 _______________________________________________ Intel-wired-lan mailing list Intel-wired-lan@osuosl.org https://lists.osuosl.org/mailman/listinfo/intel-wired-lan
WARNING: multiple messages have this Message-ID (diff)
From: Wang Hai <wanghai38@huawei.com> To: <gregkh@linuxfoundation.org>, <alice.chao@mediatek.com>, <rafael@kernel.org>, <jesse.brandeburg@intel.com>, <anthony.l.nguyen@intel.com> Cc: <intel-wired-lan@lists.osuosl.org>, <linux-kernel@vger.kernel.org> Subject: [PATCH v2] kobject: Fix slab-out-of-bounds in fill_kobj_path() Date: Tue, 20 Dec 2022 09:21:43 +0800 [thread overview] Message-ID: <20221220012143.52141-1-wanghai38@huawei.com> (raw) In kobject_get_path(), if kobj->name is changed between calls get_kobj_path_length() and fill_kobj_path() and the length becomes longer, then fill_kobj_path() will have an out-of-bounds bug. The actual current problem occurs when the ixgbe probe. In ixgbe_mii_bus_init(), if the length of netdev->dev.kobj.name length becomes longer, out-of-bounds will occur. cpu0 cpu1 ixgbe_probe register_netdev(netdev) netdev_register_kobject device_add kobject_uevent // Sending ADD events systemd-udevd // rename netdev dev_change_name device_rename kobject_rename ixgbe_mii_bus_init | mdiobus_register | __mdiobus_register | device_register | device_add | kobject_uevent | kobject_get_path | len = get_kobj_path_length // old name | path = kzalloc(len, gfp_mask); | kobj->name = name; /* name length becomes * longer */ fill_kobj_path /* kobj path length is * longer than path, * resulting in out of * bounds when filling path */ This is the kasan report: ================================================================== BUG: KASAN: slab-out-of-bounds in fill_kobj_path+0x50/0xc0 Write of size 7 at addr ff1100090573d1fd by task kworker/28:1/673 Workqueue: events work_for_cpu_fn Call Trace: <TASK> dump_stack_lvl+0x34/0x48 print_address_description.constprop.0+0x86/0x1e7 print_report+0x36/0x4f kasan_report+0xad/0x130 kasan_check_range+0x35/0x1c0 memcpy+0x39/0x60 fill_kobj_path+0x50/0xc0 kobject_get_path+0x5a/0xc0 kobject_uevent_env+0x140/0x460 device_add+0x5c7/0x910 __mdiobus_register+0x14e/0x490 ixgbe_probe.cold+0x441/0x574 [ixgbe] local_pci_probe+0x78/0xc0 work_for_cpu_fn+0x26/0x40 process_one_work+0x3b6/0x6a0 worker_thread+0x368/0x520 kthread+0x165/0x1a0 ret_from_fork+0x1f/0x30 This reproducer triggers that bug: while: do rmmod ixgbe sleep 0.5 modprobe ixgbe sleep 0.5 When calling fill_kobj_path() to fill path, if the name length of kobj becomes longer, return failure and retry. This fixes the problem. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Wang Hai <wanghai38@huawei.com> --- v1->v2: Return value type change and some formatting adjustments. lib/kobject.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/lib/kobject.c b/lib/kobject.c index a0b2dbfcfa23..3f97d903266a 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -112,7 +112,7 @@ static int get_kobj_path_length(struct kobject *kobj) return length; } -static void fill_kobj_path(struct kobject *kobj, char *path, int length) +static int fill_kobj_path(struct kobject *kobj, char *path, int length) { struct kobject *parent; @@ -121,12 +121,16 @@ static void fill_kobj_path(struct kobject *kobj, char *path, int length) int cur = strlen(kobject_name(parent)); /* back up enough to print this name with '/' */ length -= cur; + if (length <= 0) + return -EINVAL; memcpy(path + length, kobject_name(parent), cur); *(path + --length) = '/'; } pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj), kobj, __func__, path); + + return 0; } /** @@ -141,13 +145,17 @@ char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask) char *path; int len; +retry: len = get_kobj_path_length(kobj); if (len == 0) return NULL; path = kzalloc(len, gfp_mask); if (!path) return NULL; - fill_kobj_path(kobj, path, len); + if (fill_kobj_path(kobj, path, len)) { + kfree(path); + goto retry; + } return path; } -- 2.17.1
next reply other threads:[~2022-12-20 1:22 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-12-20 1:21 Wang Hai [this message] 2022-12-20 1:21 ` [PATCH v2] kobject: Fix slab-out-of-bounds in fill_kobj_path() Wang Hai 2022-12-21 11:08 ` [Intel-wired-lan] " Michal Swiatkowski 2022-12-21 11:08 ` Michal Swiatkowski 2022-12-22 6:22 ` wanghai (M) 2022-12-22 6:22 ` wanghai (M) 2023-01-09 9:37 ` Wang Hai 2023-01-09 9:37 ` [Intel-wired-lan] " Wang Hai 2023-01-09 10:33 ` Greg KH 2023-01-09 10:33 ` [Intel-wired-lan] " Greg KH 2023-01-09 11:15 ` Wang Hai 2023-01-09 11:15 ` Wang Hai 2023-01-11 15:07 ` Greg KH 2023-01-11 15:07 ` [Intel-wired-lan] " Greg KH
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