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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/debugfs-scmi | |
| 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/debugfs-scmi')
| -rw-r--r-- | Documentation/ABI/testing/debugfs-scmi | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/debugfs-scmi b/Documentation/ABI/testing/debugfs-scmi new file mode 100644 index 000000000..ee7179ab2 --- /dev/null +++ b/Documentation/ABI/testing/debugfs-scmi @@ -0,0 +1,70 @@ +What: /sys/kernel/debug/scmi/<n>/instance_name +Date: March 2023 +KernelVersion: 6.3 +Contact: cristian.marussi@arm.com +Description: The name of the underlying SCMI instance <n> described by + all the debugfs accessors rooted at /sys/kernel/debug/scmi/<n>, + expressed as the full name of the top DT SCMI node under which + this SCMI instance is rooted. +Users: Debugging, any userspace test suite + +What: /sys/kernel/debug/scmi/<n>/atomic_threshold_us +Date: March 2023 +KernelVersion: 6.3 +Contact: cristian.marussi@arm.com +Description: An optional time value, expressed in microseconds, representing, + on this SCMI instance <n>, the threshold above which any SCMI + command, advertised to have an higher-than-threshold execution + latency, should not be considered for atomic mode of operation, + even if requested. +Users: Debugging, any userspace test suite + +What: /sys/kernel/debug/scmi/<n>/transport/type +Date: March 2023 +KernelVersion: 6.3 +Contact: cristian.marussi@arm.com +Description: A string representing the type of transport configured for this + SCMI instance <n>. +Users: Debugging, any userspace test suite + +What: /sys/kernel/debug/scmi/<n>/transport/is_atomic +Date: March 2023 +KernelVersion: 6.3 +Contact: cristian.marussi@arm.com +Description: A boolean stating if the transport configured on the underlying + SCMI instance <n> is capable of atomic mode of operation. +Users: Debugging, any userspace test suite + +What: /sys/kernel/debug/scmi/<n>/transport/max_rx_timeout_ms +Date: March 2023 +KernelVersion: 6.3 +Contact: cristian.marussi@arm.com +Description: Timeout in milliseconds allowed for SCMI synchronous replies + for the currently configured SCMI transport for instance <n>. +Users: Debugging, any userspace test suite + +What: /sys/kernel/debug/scmi/<n>/transport/max_msg_size +Date: March 2023 +KernelVersion: 6.3 +Contact: cristian.marussi@arm.com +Description: Max message size of allowed SCMI messages for the currently + configured SCMI transport for instance <n>. +Users: Debugging, any userspace test suite + +What: /sys/kernel/debug/scmi/<n>/transport/tx_max_msg +Date: March 2023 +KernelVersion: 6.3 +Contact: cristian.marussi@arm.com +Description: Max number of concurrently allowed in-flight SCMI messages for + the currently configured SCMI transport for instance <n> on the + TX channels. +Users: Debugging, any userspace test suite + +What: /sys/kernel/debug/scmi/<n>/transport/rx_max_msg +Date: March 2023 +KernelVersion: 6.3 +Contact: cristian.marussi@arm.com +Description: Max number of concurrently allowed in-flight SCMI messages for + the currently configured SCMI transport for instance <n> on the + RX channels. +Users: Debugging, any userspace test suite |