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| author | Ali Ahmet Memis <ali@iusegentoo.com> | 2026-08-21 01:45:27 +0000 |
|---|---|---|
| committer | Stafford Horne <shorne@gmail.com> | 2026-08-29 07:32:26 +0100 |
| commit | 78004e9a87f240df03e2f73120d291763c32e0a7 (patch) | |
| tree | 137c22dd795222931b9d2bf2501d37cd766741aa /Documentation/ABI/testing/usb-uevent | |
| download | linux-stable-78004e9a87f240df03e2f73120d291763c32e0a7.tar.gz linux-stable-78004e9a87f240df03e2f73120d291763c32e0a7.zip | |
openrisc: fix arbitrary kernel memory access via or1k_atomic syscallgrafted
sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user
pointers, v1 and v2, and swaps the words they point to in hand-written
assembly.
l.lwz r29,0(r4)
l.lwz r27,0(r5)
l.sw 0(r4),r27
l.sw 0(r5),r29
The pointers are not checked with access_ok(). The four memory
accesses also have no exception table entries.
A caller passes a kernel address as either pointer, and the syscall
reads from and writes to it directly.
This gives an unprivileged process a kernel read/write primitive. It
overwrites kernel data such as the sys_call_table, gaining code
execution in kernel context.
Check both pointers before entering the critical section. Add fixups
for the four memory accesses so faults on valid but unmapped user
addresses return -EFAULT.
[shorne@gmail.com: fix comment style]
Fixes: 9d02a4283e9c ("OpenRISC: Boot code")
Cc: stable@vger.kernel.org
Signed-off-by: Ali Ahmet Memis <ali@iusegentoo.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Diffstat (limited to 'Documentation/ABI/testing/usb-uevent')
| -rw-r--r-- | Documentation/ABI/testing/usb-uevent | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/usb-uevent b/Documentation/ABI/testing/usb-uevent new file mode 100644 index 000000000..2b8eca4bf --- /dev/null +++ b/Documentation/ABI/testing/usb-uevent @@ -0,0 +1,27 @@ +What: Raise a uevent when a USB Host Controller has died +Date: 2019-04-17 +KernelVersion: 5.2 +Contact: linux-usb@vger.kernel.org +Description: When the USB Host Controller has entered a state where it is no + longer functional a uevent will be raised. The uevent will + contain ACTION=offline and ERROR=DEAD. + + Here is an example taken using udevadm monitor -p:: + + KERNEL[130.428945] offline /devices/pci0000:00/0000:00:10.0/usb2 (usb) + ACTION=offline + BUSNUM=002 + DEVNAME=/dev/bus/usb/002/001 + DEVNUM=001 + DEVPATH=/devices/pci0000:00/0000:00:10.0/usb2 + DEVTYPE=usb_device + DRIVER=usb + ERROR=DEAD + MAJOR=189 + MINOR=128 + PRODUCT=1d6b/2/414 + SEQNUM=2168 + SUBSYSTEM=usb + TYPE=9/0/1 + +Users: chromium-os-dev@chromium.org |