From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall 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 Signed-off-by: Stafford Horne --- Documentation/ABI/testing/debugfs-pcie-ptm | 70 ++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 Documentation/ABI/testing/debugfs-pcie-ptm (limited to 'Documentation/ABI/testing/debugfs-pcie-ptm') diff --git a/Documentation/ABI/testing/debugfs-pcie-ptm b/Documentation/ABI/testing/debugfs-pcie-ptm new file mode 100644 index 000000000..602d41363 --- /dev/null +++ b/Documentation/ABI/testing/debugfs-pcie-ptm @@ -0,0 +1,70 @@ +What: /sys/kernel/debug/pcie_ptm_*/local_clock +Date: May 2025 +Contact: Manivannan Sadhasivam +Description: + (RO) PTM local clock in nanoseconds. Applicable for both Root + Complex and Endpoint controllers. + +What: /sys/kernel/debug/pcie_ptm_*/master_clock +Date: May 2025 +Contact: Manivannan Sadhasivam +Description: + (RO) PTM master clock in nanoseconds. Applicable only for + Endpoint controllers. + +What: /sys/kernel/debug/pcie_ptm_*/t1 +Date: May 2025 +Contact: Manivannan Sadhasivam +Description: + (RO) PTM T1 timestamp in nanoseconds. Applicable only for + Endpoint controllers. + +What: /sys/kernel/debug/pcie_ptm_*/t2 +Date: May 2025 +Contact: Manivannan Sadhasivam +Description: + (RO) PTM T2 timestamp in nanoseconds. Applicable only for + Root Complex controllers. + +What: /sys/kernel/debug/pcie_ptm_*/t3 +Date: May 2025 +Contact: Manivannan Sadhasivam +Description: + (RO) PTM T3 timestamp in nanoseconds. Applicable only for + Root Complex controllers. + +What: /sys/kernel/debug/pcie_ptm_*/t4 +Date: May 2025 +Contact: Manivannan Sadhasivam +Description: + (RO) PTM T4 timestamp in nanoseconds. Applicable only for + Endpoint controllers. + +What: /sys/kernel/debug/pcie_ptm_*/context_update +Date: May 2025 +Contact: Manivannan Sadhasivam +Description: + (RW) Control the PTM context update mode. Applicable only for + Endpoint controllers. + + Following values are supported: + + * auto = PTM context auto update trigger for every 10ms + + * manual = PTM context manual update. Writing 'manual' to this + file triggers PTM context update (default) + +What: /sys/kernel/debug/pcie_ptm_*/context_valid +Date: May 2025 +Contact: Manivannan Sadhasivam +Description: + (RW) Control the PTM context validity (local clock timing). + Applicable only for Root Complex controllers. PTM context is + invalidated by hardware if the Root Complex enters low power + mode or changes link frequency. + + Following values are supported: + + * 0 = PTM context invalid (default) + + * 1 = PTM context valid -- cgit v1.3.1