title: net: usb: smsc75xx: Fix uninit-value access in __smsc75xx_read_reg
description: In the Linux kernel, the following vulnerability has been resolved:
net: usb: smsc75xx: Fix uninit-value access in __smsc75xx_read_reg
syzbot reported the following uninit-value access issue:
=====================================================
BUG: KMSAN: uninit-value in smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:975 [inline]
BUG: KMSAN: uninit-value in smsc75xx_bind+0x5c9/0x11e0 drivers/net/usb/smsc75xx.c:1482
CPU: 0 PID: 8696 Comm: kworker/0:3 Not tainted 5.8.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x21c/0x280 lib/dump_stack.c:118
kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121
__msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:975 [inline]
smsc75xx_bind+0x5c9/0x11e0 drivers/net/usb/smsc75xx.c:1482
usbnet_probe+0x1152/0x3f90 drivers/net/usb/usbnet.c:1737
usb_probe_interface+0xece/0x1550 drivers/usb/core/driver.c:374
really_probe+0xf20/0x20b0 drivers/base/dd.c:529
driver_probe_device+0x293/0x390 drivers/base/dd.c:701
__device_attach_driver+0x63f/0x830 drivers/base/dd.c:807
bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431
__device_attach+0x4e2/0x7f0 drivers/base/dd.c:873
device_initial_probe+0x4a/0x60 drivers/base/dd.c:920
bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491
device_add+0x3b0e/0x40d0 drivers/base/core.c:2680
usb_set_configuration+0x380f/0x3f10 drivers/usb/core/message.c:2032
usb_generic_driver_probe+0x138/0x300 drivers/usb/core/generic.c:241
usb_probe_device+0x311/0x490 drivers/usb/core/driver.c:272
really_probe+0xf20/0x20b0 drivers/base/dd.c:529
driver_probe_device+0x293/0x390 drivers/base/dd.c:701
__device_attach_driver+0x63f/0x830 drivers/base/dd.c:807
bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431
__device_attach+0x4e2/0x7f0 drivers/base/dd.c:873
device_initial_probe+0x4a/0x60 drivers/base/dd.c:920
bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491
device_add+0x3b0e/0x40d0 drivers/base/core.c:2680
usb_new_device+0x1bd4/0x2a30 drivers/usb/core/hub.c:2554
hub_port_connect drivers/usb/core/hub.c:5208 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5348 [inline]
port_event drivers/usb/core/hub.c:5494 [inline]
hub_event+0x5e7b/0x8a70 drivers/usb/core/hub.c:5576
process_one_work+0x1688/0x2140 kernel/workqueue.c:2269
worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415
kthread+0x551/0x590 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Local variable ----buf.i87@smsc75xx_bind created at:
__smsc75xx_read_reg drivers/net/usb/smsc75xx.c:83 [inline]
smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:968 [inline]
smsc75xx_bind+0x485/0x11e0 drivers/net/usb/smsc75xx.c:1482
__smsc75xx_read_reg drivers/net/usb/smsc75xx.c:83 [inline]
smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:968 [inline]
smsc75xx_bind+0x485/0x11e0 drivers/net/usb/smsc75xx.c:1482
This issue is caused because usbnet_read_cmd() reads less bytes than requested
(zero byte in the reproducer). In this case, 'buf' is not properly filled.
This patch fixes the issue by returning -ENODATA if usbnet_read_cmd() reads
less bytes than requested.
affected:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: d0cad871703b, lessThan: 3e0af6eec178, status: affected, versionType: git
version: d0cad871703b, lessThan: 2a36d9e2995c, status: affected, versionType: git
version: d0cad871703b, lessThan: 310f1c92f65a, status: affected, versionType: git
version: d0cad871703b, lessThan: 30bc4d7aebe3, status: affected, versionType: git
version: d0cad871703b, lessThan: cda10784a176, status: affected, versionType: git
version: d0cad871703b, lessThan: 9ffc5018020f, status: affected, versionType: git
version: d0cad871703b, lessThan: 4931e80da946, status: affected, versionType: git
version: d0cad871703b, lessThan: e9c65989920f, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 2.6.34, status: affected
version: 0, lessThan: 2.6.34, status: unaffected, versionType: custom
version: 4.14.327, lessThanOrEqual: 4.14.*, status: unaffected, versionType: custom
version: 4.19.296, lessThanOrEqual: 4.19.*, status: unaffected, versionType: custom
version: 5.4.258, lessThanOrEqual: 5.4.*, status: unaffected, versionType: custom
version: 5.10.198, lessThanOrEqual: 5.10.*, status: unaffected, versionType: custom
version: 5.15.135, lessThanOrEqual: 5.15.*, status: unaffected, versionType: custom
version: 6.1.57, lessThanOrEqual: 6.1.*, status: unaffected, versionType: custom
version: 6.5.7, lessThanOrEqual: 6.5.*, status: unaffected, versionType: custom
version: 6.6, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
