6.6-stable review patch. If anyone has any objections, please let me know.
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From: Nikita Zhandarovich n.zhandarovich@fintech.ru
[ Upstream commit 405b0d610745fb5e84fc2961d9b960abb9f3d107 ]
Syzkaller, courtesy of syzbot, identified an error (see report [1]) in aqc111 driver, caused by incomplete sanitation of usb read calls' results. This problem is quite similar to the one fixed in commit 920a9fa27e78 ("net: asix: add proper error handling of usb read errors").
For instance, usbnet_read_cmd() may read fewer than 'size' bytes, even if the caller expected the full amount, and aqc111_read_cmd() will not check its result properly. As [1] shows, this may lead to MAC address in aqc111_bind() being only partly initialized, triggering KMSAN warnings.
Fix the issue by verifying that the number of bytes read is as expected and not less.
[1] Partial syzbot report: BUG: KMSAN: uninit-value in is_valid_ether_addr include/linux/etherdevice.h:208 [inline] BUG: KMSAN: uninit-value in usbnet_probe+0x2e57/0x4390 drivers/net/usb/usbnet.c:1830 is_valid_ether_addr include/linux/etherdevice.h:208 [inline] usbnet_probe+0x2e57/0x4390 drivers/net/usb/usbnet.c:1830 usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x4d1/0xd90 drivers/base/dd.c:658 __driver_probe_device+0x268/0x380 drivers/base/dd.c:800 ...
Uninit was stored to memory at: dev_addr_mod+0xb0/0x550 net/core/dev_addr_lists.c:582 __dev_addr_set include/linux/netdevice.h:4874 [inline] eth_hw_addr_set include/linux/etherdevice.h:325 [inline] aqc111_bind+0x35f/0x1150 drivers/net/usb/aqc111.c:717 usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772 usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396 ...
Uninit was stored to memory at: ether_addr_copy include/linux/etherdevice.h:305 [inline] aqc111_read_perm_mac drivers/net/usb/aqc111.c:663 [inline] aqc111_bind+0x794/0x1150 drivers/net/usb/aqc111.c:713 usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772 usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] ...
Local variable buf.i created at: aqc111_read_perm_mac drivers/net/usb/aqc111.c:656 [inline] aqc111_bind+0x221/0x1150 drivers/net/usb/aqc111.c:713 usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772
Reported-by: syzbot+3b6b9ff7b80430020c7b@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3b6b9ff7b80430020c7b Tested-by: syzbot+3b6b9ff7b80430020c7b@syzkaller.appspotmail.com Fixes: df2d59a2ab6c ("net: usb: aqc111: Add support for getting and setting of MAC address") Signed-off-by: Nikita Zhandarovich n.zhandarovich@fintech.ru Link: https://patch.msgid.link/20250520113240.2369438-1-n.zhandarovich@fintech.ru Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/usb/aqc111.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/net/usb/aqc111.c b/drivers/net/usb/aqc111.c index 284375f662f1e..04d5573123bec 100644 --- a/drivers/net/usb/aqc111.c +++ b/drivers/net/usb/aqc111.c @@ -30,10 +30,13 @@ static int aqc111_read_cmd_nopm(struct usbnet *dev, u8 cmd, u16 value, ret = usbnet_read_cmd_nopm(dev, cmd, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, value, index, data, size);
- if (unlikely(ret < 0)) + if (unlikely(ret < size)) { + ret = ret < 0 ? ret : -ENODATA; + netdev_warn(dev->net, "Failed to read(0x%x) reg index 0x%04x: %d\n", cmd, index, ret); + }
return ret; } @@ -46,10 +49,13 @@ static int aqc111_read_cmd(struct usbnet *dev, u8 cmd, u16 value, ret = usbnet_read_cmd(dev, cmd, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, value, index, data, size);
- if (unlikely(ret < 0)) + if (unlikely(ret < size)) { + ret = ret < 0 ? ret : -ENODATA; + netdev_warn(dev->net, "Failed to read(0x%x) reg index 0x%04x: %d\n", cmd, index, ret); + }
return ret; }