51a32e8281
syzbot reported the following uninit-value access issue [1]: smsc95xx 1-1:0.0 (unnamed net_device) (uninitialized): Failed to read reg index 0x00000030: -32 smsc95xx 1-1:0.0 (unnamed net_device) (uninitialized): Error reading E2P_CMD ===================================================== BUG: KMSAN: uninit-value in smsc95xx_reset+0x409/0x25f0 drivers/net/usb/smsc95xx.c:896 smsc95xx_reset+0x409/0x25f0 drivers/net/usb/smsc95xx.c:896 smsc95xx_bind+0x9bc/0x22e0 drivers/net/usb/smsc95xx.c:1131 usbnet_probe+0x100b/0x4060 drivers/net/usb/usbnet.c:1750 usb_probe_interface+0xc75/0x1210 drivers/usb/core/driver.c:396 really_probe+0x506/0xf40 drivers/base/dd.c:658 __driver_probe_device+0x2a7/0x5d0 drivers/base/dd.c:800 driver_probe_device+0x72/0x7b0 drivers/base/dd.c:830 __device_attach_driver+0x55a/0x8f0 drivers/base/dd.c:958 bus_for_each_drv+0x3ff/0x620 drivers/base/bus.c:457 __device_attach+0x3bd/0x640 drivers/base/dd.c:1030 device_initial_probe+0x32/0x40 drivers/base/dd.c:1079 bus_probe_device+0x3d8/0x5a0 drivers/base/bus.c:532 device_add+0x16ae/0x1f20 drivers/base/core.c:3622 usb_set_configuration+0x31c9/0x38c0 drivers/usb/core/message.c:2207 usb_generic_driver_probe+0x109/0x2a0 drivers/usb/core/generic.c:238 usb_probe_device+0x290/0x4a0 drivers/usb/core/driver.c:293 really_probe+0x506/0xf40 drivers/base/dd.c:658 __driver_probe_device+0x2a7/0x5d0 drivers/base/dd.c:800 driver_probe_device+0x72/0x7b0 drivers/base/dd.c:830 __device_attach_driver+0x55a/0x8f0 drivers/base/dd.c:958 bus_for_each_drv+0x3ff/0x620 drivers/base/bus.c:457 __device_attach+0x3bd/0x640 drivers/base/dd.c:1030 device_initial_probe+0x32/0x40 drivers/base/dd.c:1079 bus_probe_device+0x3d8/0x5a0 drivers/base/bus.c:532 device_add+0x16ae/0x1f20 drivers/base/core.c:3622 usb_new_device+0x15f6/0x22f0 drivers/usb/core/hub.c:2589 hub_port_connect drivers/usb/core/hub.c:5440 [inline] hub_port_connect_change drivers/usb/core/hub.c:5580 [inline] port_event drivers/usb/core/hub.c:5740 [inline] hub_event+0x53bc/0x7290 drivers/usb/core/hub.c:5822 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703 worker_thread+0xf45/0x1490 kernel/workqueue.c:2784 kthread+0x3e8/0x540 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Local variable buf.i225 created at: smsc95xx_read_reg drivers/net/usb/smsc95xx.c:90 [inline] smsc95xx_reset+0x203/0x25f0 drivers/net/usb/smsc95xx.c:892 smsc95xx_bind+0x9bc/0x22e0 drivers/net/usb/smsc95xx.c:1131 CPU: 1 PID: 773 Comm: kworker/1:2 Not tainted 6.6.0-rc1-syzkaller-00125-ge42bebf6db29 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Workqueue: usb_hub_wq hub_event ===================================================== Similar to e9c65989920f ("net: usb: smsc75xx: Fix uninit-value access in __smsc75xx_read_reg"), 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. sysbot reported similar uninit-value access issue [2]. The root cause is the same as mentioned above, and this patch addresses it as well. Fixes: 2f7ca802bdae ("net: Add SMSC LAN9500 USB2.0 10/100 ethernet adapter driver") Reported-and-tested-by: syzbot+c74c24b43c9ae534f0e0@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+2c97a98a5ba9ea9c23bd@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=c74c24b43c9ae534f0e0 [1] Closes: https://syzkaller.appspot.com/bug?extid=2c97a98a5ba9ea9c23bd [2] Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.